Awardees

David Goldsman Receives the 2023 Lifetime Professional Achievement Award

David Goldsman (left) and Barry Nelson (right)

David Goldsman, Coca-Cola Foundation Professor in the School of Industrial and Systems Engineering at Georgia Tech, received the 2023 Lifetime Professional Achievement Award (LPAA) from the INFORMS Simulation Society (I-Sim). The award was presented on December 12, 2023, at the I-Sim Business Meeting of the 2023 Winter Simulation Conference (WSC), which was held in San Antonio, Texas. The award selection committee was chaired by Peter W. Glynn (Stanford University) with members Pierre L’Ecuyer (Université de Montréal) and Barry L. Nelson (Northwestern University).

The highest honor of the INFORMS Simulation Society, the Lifetime Professional Achievement Award is given at most annually to recognize an individual for major contributions to the field of computer simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on the field. An individual’s achievements may fall in one or more of the following categories:

contributions to research,
contributions to practice,
dissemination of knowledge,
development of software or hardware,
service to the profession, and
advancement of the status or visibility of the field.

As succinctly stated by his nominator James Wilson,

Over the past 40 years, David Goldsman has made seminal contributions to the field of computer simulation as well as the larger fields of [Operations Research and Management Science] ORMS, [Industrial & Systems Engineering] ISE, [Healthcare Systems Engineering] HSE, and statistical [Ranking & Selection] R&S. Those contributions are remarkable not only for their scope and impact but also for the remarkably long time period over which that impact has been sustained in all its dimensions. The I-Sim Lifetime Professional Achievement Award is appropriate recognition for such a remarkable career and such a worthy individual.

Contributions to research:

Dave’s research contributions are broad in coverage and impact, and deep in methodological rigor and innovation. Three bodies of work of particular significance are in simulation output analysis; ranking and selection (R&S) for simulation optimization; and healthcare systems engineering (HSE).

Beginning with his dissertation and the associated paper

David Goldsman and Lee Schruben. "Asymptotic properties of some confidence interval estimators for simulation output." Management Science 30.10 (1984): 1217-1225,

Dave has been an innovator in creating and evaluating point and confidence-interval estimators for parameters of the steady-state simulation output process, including the mean, variance and quantiles of the limiting distributions as well as the autocorrelation structure of the process. Of particular note are contributions to the method of standardized time series and to “batching,” alone and in combination with other methods. His paper

Christos Alexopoulos and David Goldsman. "To batch or not to batch?." ACM Transactions on Modeling and Computer Simulation (TOMACS) 14.1 (2004): 76-114

received the I-Sim Outstanding Publication Award in 2007 and is still the most comprehensive comparison of the two most-popular methods for creating confidence intervals for the steady-state mean: independent replications and batch means.

Dave’s initial work on R&S was in statistics and focused on “multinomial selection,” which means selecting the treatment that is most likely to be the best. This work was joint with a founder of the field, Robert Bechhofer, and culminated in the comprehensive reference text,

Robert E. Bechhofer, Thomas J. Santner, and David Goldsman. Design and Analysis of Experiments for Statistical Selection, Screening and Multiple Comparisons, John Wiley and Sons, New York (1995).

Dave is credited with introducing and adapting the R&S problem of selecting the treatment with the best mean performance to selecting the best simulated system beginning with a Winter Simulation Conference session he organized in 1983. His papers on the topic represent the first concerted effort to adapt statistical R&S procedures to large-scale simulation experiments, where the usual assumptions about independent, homoscedastic, normally distributed responses do not always apply; such methods have become a mainstay of research and are the only rigorous simulation optimization tools applied routinely by practitioners. His advocacy of R&S in the paper

David Goldsman, Barry L. Nelson, and Bruce Schmeiser. Methods for selecting the best system. Proceedings of the 1991 Winter Simulation Conference. Institute of Electrical and Electronics Engineers, 177—186,

was instrumental to its widespread adoption, and the paper itself was named one of ten landmark papers in the Winter Simulation Conference for the period 1968—2006.

Since the 1990s Dave has pursued research addressing public-health problems, including the eradication of Guinea-worm disease in Sudan; bed-allocation and patient-scheduling for hospitals and community clinics in Atlanta and San Diego; public school programs for vaccination of children against Hepatitis B in Denver; interventions for pandemic influenza; and analysis of organ-transplant policies. In addition to publications in our familiar journals, much of this work has appeared in prestigious scientific and domain-specific journals such as PLOS One, Symmetry, Transplant Infectious Disease and Infectious Disease Modeling. This work has made substantial contributions to practice through collaborations with domain experts and Dave’s extensive consulting activities.

Dissemination of knowledge:

Dave has published 83 journal articles, 5 books, 4 edited books, 19 refereed book chapters and 95 conference proceedings, garnering 8,355 citations in Google Scholar. He has supervised 34 Ph.D. students, 9 M.S. students, 2 M.Eng. students, 9 postdoctoral fellows and 29 foreign-exchange students. His Ph.D. students have achieved first, second and third place finishes in the annual Pritsker Doctoral Dissertation Award competition, received the IIE Transactions Best Paper in Operations Award, and have had highly successful careers in academic, governmental, military and commercial organizations.

Dave co-organized and co-presented the High School Teachers Workshop on Operations Research that was a fixture at the INFORMS Annual Meetings from 1996 to 2014. This workshop showed hundreds of teachers how they could bring operations research into their high school mathematics classes. In 1987 he founded the WSC Doctoral Colloquium and later arranged for it to be sponsored by I-Sim. The Colloquium continues to be an amazingly impactful forum for fostering research among junior scholars in a low-pressure forum with an interested and engaged audience, possibly leading to connections and jobs that last a career.

Due to his thought leadership Dave has been invited to present keynote lectures and plenary addresses all over the world, including at the International Conference on Computers and Industrial Engineering in Taiwan; the Asia Simulation Conference in South Korea; the ENIM IFAC International Conference on Modeling and Simulation in Tunisia; and the Joint ISEM—Centre for Next Generation Logistics C4NGL Workshop in Singapore.

Service to the profession:

Dave has served the profession in the broadest possible sense, including exemplary leadership in I-Sim and the Winter Simulation Conference.

For WSC he has been associate proceedings editor, program chair, and board member representing IIE (now IISE). As a board member he held the offices of secretary, vice chair and chair, and played a leading role in establishing the WSC Foundation, on whose board he later served.

In his role as I-Sim President from 1994—1996, Dave (a) conceived of the idea of the Lifetime Professional Achievement Award; (b) initiated the creation and ongoing maintenance of the I-Sim web site; and (c) managed I-Sim’s transition during the merger of ORSA and TIMS into INFORMS, a merger that also had significant impact on the organization and financial structure of WSC.

Dave has held editorial positions with Management Science, Operations Research Letters, IISE Transactions and numerous other publications. His editorial service, both as a board member and especially as a careful, caring and relentlessly positive referee, is legendary.

He received the I-Sim Distinguished Service Award in 2002, and there have been mountains of service since then. However, Dave’s uncredited service almost certainly dominates what has been recorded. This uncredited service includes tens of graduate students who needed a recommendation letter or a little advice to get them unstuck; colleagues whose research needed an extra polish or a push; hurry-up referee’s reports or editing to cover for someone else who failed to do it; and colleagues who needed to be picked up at the airport or have their talk covered when they couldn’t make it.

Advancement of the status of the field:

Dave is an exceptional ambassador for simulation both in the U.S. and abroad. His numerous personal connections have brought researchers and practitioners from outside our field into it, and his successful consulting engagements with some forty companies have demonstrated the value of modeling and simulation in practice.

Professional recognition:

Dave received the Alpha Pi Mu Teacher of the Year Award from the undergraduate and graduate students in the School of Industrial and Systems Engineering at Georgia Tech in 1986, 1987, 1991, and 1997. For his numerous contributions to the fields of ORMS and ISE, Dave received the Operations Research Division Award from IIE in 1996. He received the Distinguished Service Award from I-Sim in 2002; and in 2007 he received I-Sim’s Outstanding Simulation Publication Award. In 2006 Dave received a Fulbright Teaching Fellowship to hold faculty positions in the Department of Industrial Engineering at Bogaziçi University and in the Faculty of Management of Sabancı University (Istanbul, Turkey). In May 2012 he received the Fellow Award from IIE. In May 2018 he received the Operations Research (OR) Division Teaching Award from IISE, and in the fall of 2018 he was recognized as a Hesburgh Award Teaching Fellow by Georgia Tech. In January 2020 Dave received the Georgia Power Professor of Excellence Award, and in December 2020 he received the INFORMS Fellow Award.

The international simulation community has been greatly enriched by the remarkable contributions of Dave Goldsman over the past 40 years, as have the related fields of statistics, public health, education, and transportation. His career is an exemplar of the impact that the Lifetime Professional Achievement Award of the INFORMS Simulation Society was created to recognize.

Barry L. Nelson Receives the 2022 Lifetime Professional Achievement Award

Barry L. Nelson, the Walter P. Murphy Professor in the Department of Industrial Engineering and Management Sciences at Northwestern University, received the 2022 Lifetime Professional Achievement Award (LPAA) from the INFORMS Simulation Society (ISIM). The award was presented both online and in person on December 11, 2022, at the opening session of the 2022 Winter Simulation Conference (WSC), which was held physically in Singapore. The award selection committee for 2022 was chaired by Pierre L’Ecuyer (Université de Montréal), with members Peter W. Glynn (Stanford University) and James R. Wilson (North Carolina State University).

contributions to research,
contributions to practice,
dissemination of knowledge,
development of software or hardware,
service to the profession, and
advancement of the status or visibility of the field.

Barry Nelson’s extraordinary contributions to the field of computer simulation over the past four decades were forcefully and concisely summarized by Shane Henderson (Cornell University):

In high-impact research, in translation of research to practice, in framing key research questions and future research directions, in training the next generation of simulation researchers, in education both in the university classroom and beyond, in professional service roles and every other dimension I can think of he is a leader and role model.

Barry has made seminal research contributions to many areas of computer simulation, including design and analysis of simulation experiments on models of stochastic systems; statistical ranking, selection, screening, and multiple comparisons; simulation optimization; simulation metamodeling; simulation input modeling, especially for multivariate and nonstationary input processes; uncertainty quantification; variance reduction (efficiency improvement) techniques; and sequential analysis. Beyond the field of computer simulation, Barry has had a significant impact on the larger disciplines of industrial and systems engineering (ISE), operations research and the management sciences (ORMS), applied statistics, and applied probability. Barry has followed up his numerous theoretical and methodological contributions with major contributions to practice in a broad diversity of application domains, including computer performance evaluation, production and procurement planning for manufacturing of personal computers, wind and solar power simulation, election poll staffing, supply chain modeling, design of an automated material handling system for the Port Authority of Singapore, and financial engineering models of crop insurance risk.

Barry’s contributions to the dissemination of knowledge include his published work, his distinguished lectures, his research awards, his teaching awards, and his greatest contribution of all―his teaching and advising of students. To provide more perspective on the full significance of Barry’s publications over the past 40 years, we note that as of May 10, 2023, Barry had accumulated 12,944 citations in Google Scholar with an h-index of 61. Altogether he has published 105 archival journal articles, 13 book chapters, 3 books, and 117 refereed proceedings papers. The following publications warrant special mention. Barry and his students or collaborators received ISIM’s Outstanding Simulation Publication Award three times (in 2006, 2013, and 2015) for the following articles:

Boesel, J., B. L. Nelson, and S. Kim, “Using Ranking and Selection to ‘Clean Up’ after Simulation Optimization," Operations Research 51 (2003), 814‒825.
Ankenman, B. E., B. L. Nelson, and J. Staum, “Stochastic Kriging for Simulation Metamodeling,” Operations Research 58 (2010), 371‒382.
W. Xie, B. L. Nelson, and R. R. Barton, “A Bayesian Framework for Quantifying Uncertainty in Stochastic Simulation," Operations Research 62 (2014), 1439‒1452.

Barry has been extraordinarily effective in disseminating knowledge about simulation and in advancing the status and visibility of the field through his keynote addresses and distinguished lectures delivered at universities, conferences of professional societies, research organizations, governmental organizations, and commercial enterprises worldwide. The following lectures deserve special mention:

Keynote Address, International Workshop on Mathematical Methods and Tools in Computer Simulation, St. Petersburg, Russia, May 1994.
Plenary Lecture, 2007 INFORMS Simulation Society Workshop, Fontainebleau, France, July 2007.
Keynote Address, IIE Annual Conference and Expo, Vancouver, Canada, May 2008.
Keynote Address, Asian Simulation and Modeling Conference, Bangkok, Thailand, January 2009.
Omega Rho Distinguished Lecture, INFORMS Annual Meeting, November 2011.
Titans of Simulation Lecture, Winter Simulation Conference, December 2013.
Keynote Address, Operational Research Society 7th Simulation Workshop, Worcestershire, England, April 2014.
Keynote Address, Winter Simulation Conference, December 2017.
Alan B. Pritsker Scholars Distinguished Lecture, Purdue University, April 2018.
Plenary Lecture, 13th International Conference in Monte Carlo & Quasi-Monte Carlo Methods in Scientific Computing, Rennes, France, July 2018.
Keynote Address, INFORMS Annual Meeting, November 2020.

Barry has also delivered invited lectures at 47 universities throughout the world. Moreover, he has made numerous presentations at such nonacademic organizations as General Motors Research and Development, the MITRE Corporation, the Norwegian Defense Establishment, SAS Institute, and Simio LLC.

By Barry’s teaching and advising of undergraduate and graduate students, he and his former students have made an unsurpassed contribution to the worldwide dissemination of knowledge about simulation. As of May 2023, Barry had completed the supervision of 5 senior honors thesis students, 5 master’s thesis students, 31 Ph.D. students, and 2 postdoctoral researchers. Among Barry’s former graduate students, 12 hold senior positions in commercial and research organizations. Moreover, 23 of Barry’s former students are faculty members at leading universities in China, Hong Kong, South Korea, Taiwan, Thailand, Turkey, the United Kingdom, and the United States. The impact on the simulation field made by Barry and all his former students will almost surely persist for a long time.

Barry has also received the following research awards beyond ISIM’s Outstanding Simulation Publication Awards that he received in 2006, 2013, and 2015:

David F. Baker Distinguished Research Award from the Institute of Industrial and Systems Engineers (IISE) in 2019.
Best Paper Award from IIE Transactions (now IISE Transactions) in 2006, 2009, and 2013:
- Hong, L. J., and B. L. Nelson, “Selecting the Best System when Systems are Revealed Sequentially," IIE Transactions 39 (2007), 723‒734.
- Tsai, S. C., and B. L. Nelson, “Fully Sequential Selection Procedures with Control Variates,"IIE Transactions 42 (2009), 71‒82.
- Xu, W. L., and B. L. Nelson, “Empirical Stochastic Branch-and-Bound for Optimization via Simulation," IISE Transactions 45 (2013), 685‒698.

Barry has received numerous teaching awards from Northwestern University, The Ohio State University, the IISE Operations Research Division, and the IISE Modeling and Simulation Division. The following partial list exemplifies the significance of all the teaching awards that Barry has received:

Alpha Pi Mu Outstanding Faculty Award, voted by the Department of Industrial and Systems Engineering seniors, The Ohio State University (1989, 1995).
Charles E. MacQuigg Award for Outstanding Teaching, a college-wide award from the College of Engineering, The Ohio State University (1992).
Alumni Award for Distinguished Teaching, a university-wide award from The Ohio State University (1994). This is the highest award for teaching given by the university, and it includes induction into the OSU Academy of Teaching.
Graduate Teaching Award, Student INFORMS Chapter, Department of Industrial Engineering and Management Sciences (IEMS), Northwestern University (1995‒1996, 1996‒1997, 1997‒1998, 1999‒2000, 2000‒2001, 2002‒2003, 2005‒2006, 2006‒2007, 2012‒2013).
Northwestern Alumni Association Excellence in Teaching Award (2003).
McCormick School of Engineering and Applied Science Teacher of the Year Award, Northwestern University (1997-1998, 2006‒2007).
Cole-Higgins Award for Teaching Excellence, McCormick School of Engineering and Applied Science, Northwestern University (2021‒2022).

Barry’s groundbreaking contributions to the development of software include the following:

Ranking-and-selection algorithms implemented in Arena, OptQuest, and Simio.
Input-uncertainty algorithms implemented in Simio.
MORE plot implemented in Simio and Simul8.
Shapley-effects algorithms implemented in a CRAN R package.
Input-model averaging algorithm implemented in a CRAN R package.

Barry’s contributions in service to the international simulation community are extraordinary for their wide scope and the length of time over which those contributions have been sustained:

Each WSC position from Session Chair to Board Chair (1983‒present).
Trustee of the WSC Foundation (2008‒2012).
Each ISIM position from Newsletter Editor to President (1986‒1994).
Each ISIM committee and many high-level INFORMS committees (1983‒present).
Editor-in-Chief of Naval Research Logistics (2006‒2008).
Area Editor of Operations Research and Surveys in Operations Research and Management Science (2009‒2011).
Area Editor of Operations Research (1998‒2000).
Member of National Science Foundation (NSF) review panel (1990, 1992, 2000, 2001, 2003, 2004, 2009, 2010, 2012); reviewer of NSF proposals (1987, 1989, 1990, 1991, 1996).
External reviewer of many academic departments of ISE and ORMS (2008‒2017).

In recognition of Barry’s yeoman service to the simulation profession, he received the ISIM Distinguished Service Award (2003).

We in the international simulation community are the beneficiaries of Barry Nelson’s remarkable contributions over the past 40 years to the field of computer simulation as well as the allied disciplines of ISE, MSOR, applied statistics, and applied probability. His career epitomizes the highest ideals of the Lifetime Professional Achievement Award of the INFORMS Simulation Society.

Peter W. Glynn Receives the 2021 Lifetime Professional Achievement Award

Peter W. Glynn, the Thomas Ford Professor of Engineering in the Department of Management Science & Engineering at Stanford University, received the 2021 Lifetime Professional Achievement Award (LPAA) from the INFORMS Simulation Society. The award was presented at the opening session of the 2021 Winter Simulation Conference (WSC), which was held both online and in person, on December 13, 2021. The award selection committee for 2021 was chaired by James R. Wilson (North Carolina State University), with members David Goldsman (Georgia Institute of Technology) and Pierre L’Ecuyer (Université de Montréal).

The highest honor of the INFORMS Simulation Society, the Lifetime Professional Achievement Award is given at most annually to recognize an individual for major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on computer simulation. An individual’s achievements may fall in one or more of the following categories:

contributions to research,
contributions to practice,
dissemination of knowledge,
development of software or hardware,
service to the profession, and
advancement of the status or visibility of the field.

Peter Glynn’s multifaceted contributions to the field of computer simulation were memorably summarized by Ward Whitt (Columbia University) in a single sentence: “In my opinion, Peter is the preeminent contributor to the theoretical foundations of stochastic simulation.” Yet this striking assessment is perhaps an understatement in some respects. Over the past 40 years, Peter’s research contributions have also had a significant impact on the larger disciplines of operations research and the management sciences (ORMS), applied statistics, applied probability, and indeed all the scientific, engineering, and technological disciplines. Moreover, Peter has followed up his numerous theoretical and methodological contributions with ongoing, in-depth advice to many organizations that are seeking to apply those contributions to a broad diversity of critical problems currently facing society. Peter has made equally significant contributions to the dissemination of knowledge through his extensive archival publications; his lectures worldwide; and his teaching and advising of a large number of students, of whom many have already had distinguished careers. Peter has capped this extraordinary performance with service to all the aforementioned disciplines as editor-in-chief of some of the leading journals in those disciplines as well as an editor of two series of books published by one of the world’s leading publishers in science, the humanities, technology, and medicine. In the rest of this article, we elaborate on these contributions.

Beginning with his doctoral dissertation research, Peter and many of his students and collaborators have established a rigorous foundation for representing the dynamic structure of a regenerative simulation using an appropriate (discrete-time) general-state-space Markov chain. Beyond having a significant impact on the regenerative method of analysis for steady-state simulations, this work provides a basis for the analysis of Markov chain Monte Carlo methods in statistics.

Closely related to Peter’s research on regenerative simulation is his work on representing the structure and operation of a discrete-event system as a generalized semi-Markov process (GSMP). Such a continuous-time stochastic process provides a convenient framework for modeling and analysis of a large class of discrete-event simulations. Peter’s work on this topic is documented in his article titled “On the Role of Generalized Semi-Markov Processes in Simulation Output Analysis,” which appeared in the Proceedings of the 1983 Winter Simulation Conference, and in his article titled “A GSMP Formalism for Discrete Event Systems,” which appeared in Proceedings of the IEEE in 1989. As of May 2, 2022, Glynn (1983) and Glynn (1989) had accumulated 390 citations in Google Scholar.

In 1989 Peter and Donald Iglehart published the article titled “Importance Sampling for Stochastic Simulations” in Management Science. This article is a cornerstone in the development of importance-sampling estimators computed from (dependent) stochastic processes. Moreover, it has stimulated the design of efficient rare-event simulation algorithms, which have been extensively applied to the performance evaluation of complex queueing networks and high-reliability systems such as computer networks and nuclear power plants. A related paper on rare-event simulation titled “Variance Reduction in Mean Time to Failure Distributions” was published by Peter and his collaborators Perwez Shahabuddin, Victor Nicola, Philip Heidelberger, and Ambuj Goyal in the Proceedings of the 1988 Winter Simulation Conference. A clear indication of the impact of Glynn and Iglehart (1989) and Shahabuddin et al. (1988) on simulation theory and practice is that as of May 2, 2022, these two articles had accumulated 833 citations in Google Scholar.

Sensitivity analysis and stochastic optimization are two closely related areas in which Peter’s research contributions have been of central interest to the international simulation community. Peter is one of the pioneers in the development of the likelihood-ratio method for gradient estimation as documented in his article titled “Likelihood Ratio Gradient Estimation: An Overview,” which appeared in the Proceedings of the 1987 Winter Simulation Conference, and in his article titled “Likelihood Ratio Gradient Estimation for Stochastic Systems,” which appeared in the Communications of the ACM in 1990. These seminal articles have also had a significant impact on the area of stochastic optimization as evidenced by Peter’s article titled “Stochastic Approximation for Monte Carlo Optimization,” which appeared in the Proceedings of the 1986 Winter Simulation Conference. As of May 2, 2022, Glynn (1986, 1987, 1990) had collectively accumulated 949 citations in Google Scholar.

In the analysis of steady-state simulations, one of the long-standing problems is the detection and elimination of an initial transient. In 1992 Peter and his collaborators Søren Asmussen and Hermann Thorisson published a groundbreaking article titled “Stationarity Detection in the Initial Transient Problem” in the ACM Transactions on Modeling and Computer Simulation (TOMACS). To avoid initialization bias, this article provides the first exact algorithm for sampling from the equilibrium distribution of a finite-state, irreducible Markov chain in which the only known parameter is the number of states. This article has spawned many lines of research not only for steady-state simulation analysis but also for sampling from the solutions of stochastic differential equations. As of May 2, 2022, Asmussen, Glynn, and Thorisson (1992) had accumulated 157 citations in Google Scholar.

The foregoing discussion merely scratches the surface of Peter’s research contributions so as to exemplify the enduring interest in that work. In the following observations we find the ultimate evidence of the impact of Peter’s research on many scientific, engineering, and technological disciplines well beyond the field of simulation: (i) in 1998 he was elected a Fellow of the Institute of Mathematical Statistics (IMS); (ii) in 2007 he was elected a Fellow of INFORMS; (iii) in 2010 he and Søren Asmussen received the John von Neumann Theory Prize from INFORMS; and (iv) in 2012 he was elected a member of the National Academy of Engineering.

The impact of Peter’s contributions to practice is commensurate with the impact of his contributions to research. In particular he has worked closely on a continuing basis with many commercial, governmental, medical, and research organizations that are seeking to apply his research and expertise to a wide range of urgent technical and societal problems. A brief list of some of these application areas is the following: modeling the natural history of breast cancer, modeling the demand for hospital care by COVID-19 patients, predicting the durations of pediatric surgeries, managing power consumption of networks of computer chips, managing capacity and inventory in manufacturing systems, analyzing diversity in organizations and communities, modeling water releases in a network of reservoirs, and analyzing the trading of securities. From a broader perspective, Peter has made significant contributions to the practice of simulation and ORMS as well as science, engineering, and technology in general.

Peter’s achievements in the dissemination of knowledge encompass his published work; his distinguished lectures; and his greatest achievement of all―his teaching and advising of students. To provide more perspective on the full significance of Peter’s publications over the past 40 years, we note that as of May 2, 2022, Peter had accumulated 18,500 citations in Google Scholar with an h-index of 66. Altogether he has published 185 archival journal articles, 26 book chapters, 2 books, and 98 refereed proceedings papers. Beyond Peter’s publications that were previously discussed, the following publications warrant special mention. Peter and his students or collaborators received the INFORMS Simulation Society’s Outstanding Simulation Publication Award three times (in 1993, 2009, and 2015, respectively) for the following publications:

Fox, B. L., and P. W. Glynn. 1990, “Discrete-time Conversion for Simulating Finite-Horizon Markov Processes.” SIAM Journal on Applied Mathematics 50 (5): 1457‒1473.
Asmussen, S., and P. W. Glynn. 2007. Stochastic Simulation: Algorithms and Analysis. Stochastic Models and Applied Probability 57. New York: Springer.
Rhee, C.-H., and P. W. Glynn. 2015. “Unbiased Estimation with Square Root Convergence for SDE Models.” Operations Research 63 (5): 1026‒1043.

Similarly, Peter and his students or collaborators received the INFORMS Applied Probability Society’s Best Publication Award for the following article:

Blanchet, J., P. Glynn, and J. C. Liu. 2007. “Fluid Heuristics, Lyapunov Bounds and Efficient Importance Sampling for a Heavy-Tailed G/G/1 Queue.” Queueing Systems: Theory and Applications 57:99‒113.

A common theme running through many of the letters of support for Peter’s LPAA nomination is that Asmussen and Glynn (2007) has become a definitive doctoral-level textbook on stochastic simulation, having accumulated 1,919 citations in Google Scholar.

Peter has been particularly effective in disseminating knowledge about simulation and in advancing the status and visibility of the field though his distinguished lectures delivered at universities, conferences of professional societies, and research organizations worldwide. The following lectures deserve special mention:

IMS Medallion Award and Lecture, Institute of Mathematical Statistics, 1995;
Lunteren Lecture, Delft University of Technology, The Netherlands, 2007;
Wasserstrom Lecture, Northwestern University, 2013;
Alan B. Pritsker Scholars Distinguished Lecture, Purdue University, 2014;
Markov Lecture, Applied Probability Society, INFORMS Annual Meeting, 2014;
Titans of Simulation Talk: “Uncertainty and Risk: Simulations, Stochastics and Statistics,” Winter Simulation Conference, 2019; and
Philip McCord Morse Lectureship Award, INFORMS Annual Meeting, 2020.

The eminent mathematician Paul Halmos made the following trenchant observation about teaching and advising at the doctoral level: “Directing a Ph.D. student is a kind of teaching, perhaps the most challenging and interesting kind.” In this respect Peter is certainly one of the most effective teachers in the international simulation community. As of October 2021, Peter had completed the supervision of 48 Ph.D. students. Among Peter’s former students, 26 hold senior positions in commercial, medical, and research organizations worldwide. Moreover, 22 of Peter’s former students are faculty members at leading universities in Australia, Hong Kong, India, Lebanon, Mexico, Taiwan, the United Kingdom, and the United States. Among Peter’s former students in academia, 8 are assistant professors, 2 are associate professors, 8 are full professors, and 4 are chaired full professors. Peter Glynn and his former students have had an unsurpassed impact on the dissemination of knowledge about simulation and on the advancement of the status and visibility of the field; and that impact will almost surely be sustained in all its dimensions over a remarkably long period of time.

We close this discussion with an appreciation of Peter’s extraordinary service to the scientific, engineering, and technological professions over the past 40 years. Peter served as Co-Editor of the Journal of Computational Finance from 1997 to 2001. He served as the Founding Editor-in-Chief of Stochastic Systems, the flagship journal of the INFORMS Applied Probability Society, during the period 2009‒2014. The latter tour of duty was soon followed by Peter’s service as Editor-in-Chief of the Journal of Applied Probability, the oldest journal devoted to research in the field of applied probability, during the period 2016‒2018; and at the same time Peter served as Editor-in-Chief of the companion journal Advances in Applied Probability. He has also served on the editorial boards (or editorial advisory boards) of Applied Stochastic Models and Data Analysis (1985‒1991); Stochastic Models (1987‒1998); Queueing Systems: Theory and Applications (2010‒present); Stochastic Systems (2017‒present); and Mathematics of Operations Research (2017‒present). Beyond his editorial work on archival journals, Peter has also had leading editorial roles for the following series of books:

Editor (with Stephen M. Robinson) of the Springer Series in Operations Research (1995‒2004); and
Editor-in-Chief (with Andreas E. Kyprianou, Yves Le Jan, and Kavita Ramanan), Springer Series in Probability Theory and Stochastic Modeling (2015‒present).

Peter’s service to the simulation profession in particular requires special elaboration. In the foregoing discussion of Peter’s publications on modeling and analysis of discrete-event simulations using GSMPs, we see that one of his seminal articles on this topic was published in the WSC Proceedings. Similarly in the discussion of Peter’s articles on importance sampling, we see that one of the articles was published in what is now called the Stochastic Models and Simulation Department of Management Science, while the other article was published in the WSC Proceedings. In the discussion of Peter’s articles on sensitivity analysis and stochastic optimization, we see that two of the key articles were published in the WSC Proceedings. Finally, Peter’s pioneering article on the initial transient problem was published in TOMACS. Peter has consistently published much of his high-profile work in the leading publication outlets for simulation theory and practice; and by doing this for 40 years, Peter has significantly advanced the status and visibility of not only the simulation literature but also the entire simulation profession.

We in the international simulation community are among the main beneficiaries of Peter Glynn’s remarkable contributions to science, engineering, and technology over the past 40 years. His career epitomizes the highest ideals of the Lifetime Professional Achievement Award of the INFORMS Simulation Society.

2021 LPAA Selection Committee:

James R. Wilson (Chair)
David Goldsman
Pierre L'Ecuyer

Pierre L'Ecuyer Receives the 2020 Lifetime Professional Achievement Award

Top: Pierre L'Ecuyer in front of the Galilea Sea (Israel). Bottom: on the Col du Galibier (France).

Pierre L’Ecuyer, professor in the Département d’Informatique et de Recherche Opérationnelle (DIRO) at the University of Montreal, received the 2020 Lifetime Professional Achievement Award from the INFORMS Simulation Society. The award was presented at the opening session of the 2020 Winter Simulation Conference, which was held online, on December 14, 2020. The award selection committee for 2020 was chaired by Dave Goldsman (Georgia Tech), with members Lee W. Schruben (University of California, Berkeley) and James R. Wilson (North Carolina State University). The highest honor of the INFORMS Simulation Society, the Lifetime Professional Achievement Award is given at most annually to recognize an individual for major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on computer simulation. An individual’s achievements may fall in one or more of the following categories:

contributions to research,
contributions to practice,
dissemination of knowledge,
development of software or hardware,
service to the profession, and
advancement of the status or visibility of the field.

The period of professional accomplishment for a recipient should normally be at least twenty years.

Pierre L’Ecuyer has long been regarded as one of the very top researchers in the field of discrete-event stochastic simulation, where he has made significant advances across a wide swath of important topic areas. In Google Scholar he has 15,713 citations and an h-index of 67 as of February 7, 2021. Pierre’s education path gave him a great toolkit: he received his Bachelor’s degree in Mathematics in 1972, his M.Sc. in Operations Research in 1980, and his Ph.D. in Computer Science (with an orientation in Operations Research) in 1983, all from the Université de Montréal. He served as a professor during the period 1982–1990 in the Computer Science Department at Laval University before taking his “permanent” position in DIRO, when he returned home to the University of Montreal in 1990. Pierre has also taken visiting positions over the years at numerous prestigious schools around the world.

Pierre has made numerous major contributions to simulation research over the past four decades; and in the process he has performed a key role not only in shaping the research agenda for the field of simulation but also in setting the standards for high-quality research in the field. Pierre is the world’s undisputed expert in uniform random number generation. He knows all the methods, has implemented and rigorously tested every algorithm, has developed the most-widely used generators, and covers the theory and practice of random number generation like no one else before him. For two decades, Pierre’s TestU01 software library has been the gold-standard suite of procedures for empirically testing the performance of random number generators. Researchers and practitioners in every field encounter Pierre’s handiwork, which includes state-of-the-art, public-domain software libraries that can be used in the real world. This makes our field look very good!

Pierre’s work is published in the best journals, and it entails much, much more than just random number generation. Pierre has published 123 articles in archival journals, 26 articles in books or encyclopedias, and 130 papers in the refereed proceedings of conferences. He has brilliant papers on stochastic approximation and simulation methodologies, combining knowledge from number theory, probability theory, and optimization in clever and original ways. This body of work has been recognized by the INFORMS Simulation Society’s Outstanding Simulation Publication Award, which Pierre won in 1999 and again in 2009 and yet again in 2018!

Beyond his publications, Pierre has actively disseminated knowledge about simulation to a wide range of audiences. He is a popular, engaging speaker, and has made over 500 presentations at universities, research organizations, and conferences around the globe. Many of those have been prestigious plenary and “Titan” talks, attended by cross-disciplinary audiences numbering in the hundreds. It is noteworthy that Pierre has numerous papers on the applications of simulation in a broad diversity of areas, including dynamic programming, general operations research, variance reduction techniques, quasi-Monte Carlo analysis (especially with respect to financial systems), and large-scale queueing networks (e.g., service and call centers).

In terms of leadership and service to the field of simulation, Pierre’s contributions are significant and have substantially advanced the field. He is an unbelievably active referee, having provided thoughtful, rigorous, helpful reviews for over 160 journals! He has also put forth a huge amount of work in editorial and conference-organization roles, serving on numerous committees of professional societies and international conferences. While serving as Simulation Department Editor of Management Science from 1993 to 1997, Pierre advanced dramatically the status and visibility of that department in the international simulation community as well as the international operations-research/management-science community. He also served as the Editor-in-Chief of one of the bellwether journals in the field of simulation, ACM Transactions on Modeling and Computer Simulation (TOMACS), from 2010 to 2013; and during that period, TOMACS underwent unprecedented growth in the scope and volume of articles published. For all of this work, and more, he received the INFORMS Fellow Award in 2006, and he received the Distinguished Service Award from the INFORMS Simulation Society in 2011. He received the ACM SIGSIM Distinguished Contribution Award in 2016.

Pierre has also been a leader in education, a job that he clearly loves. He has served as the research supervisor of 12 doctoral students, 40 master’s-thesis students, 23 postdoctoral fellows, and over 63 internships by undergraduates and master’s-level graduate students. Many of these former students have themselves become distinguished researchers or practitioners in simulation-related fields. He is also active on the advisory committees of numerous additional master’s and doctoral students.

In summary, Pierre L’Ecuyer has made exceptional contributions to the field of discrete-event simulation through his research, contributions to practice, dissemination of knowledge, development of software, leadership/service, and contributions to the status of our field. Several letters of endorsement from distinguished individuals accompanied Pierre’s nomination for the Lifetime Professional Achievement Award. Two themes running through these letters are that Pierre has had an incredible amount of productivity and that he is a world-class scholar, researcher, colleague, and leader in the field of simulation and in the larger fields of operations research and the management sciences. Pierre L’Ecuyer’s remarkable career epitomizes the highest ideals of the Lifetime Professional Achievement Award of the INFORMS Simulation Society.

2020 LPAA Selection Committee:

James R. Wilson
Lee W. Schruben
David Goldsman (Chair)

James R. Wilson Receives the 2019 Lifetime Professional Achievement Award

Lee Schruben and James R. Wilson

James R. Wilson, Professor Emeritus in the Edward P. Fitts Department of Industrial and Systems Engineering at North Carolina State University (NCSU), is the recipient of The INFORMS Simulation Society’s Lifetime Professional Achievement Award (LPAA). The Lifetime Professional Achievement Award is the highest honor of the Society, given occasionally, but at most once a year. The purpose of this award is to recognize major contributions to the field of simulation that are sustained over a professional career, with the critical consideration being the total impact of those contributions on the field of computer simulation.

Throughout his 40-year professional career, Prof. Wilson has been a giant of the simulation community. He has authored 116 research papers in the leading archival journals, written 10 book chapters, and published 98 articles in Conference Proceedings, mostly in the peer-reviewed Proceedings of the Winter Simulation Conference. His research has been recognized by awards such as the Jacob Wolfowitz Prize for Theoretical Advances in the Mathematical and Management Sciences, the Outstanding Simulation Publication Award from the INFORMS Simulation Society, and multiple Best Paper Awards in Operations Engineering and Analysis from IISE Transactions. He was elected a Fellow of the Institute of Industrial and Systems Engineers in 2002, and an INFORMS Fellow in 2005. In 2013, he received the David F. Baker Distinguished Research Award from the Institute of Industrial Systems Engineers.

Prof. Wilson’s nomination letters were from global leaders in simulation research. They described his specific papers as “a tour-de-force”, “foundational”, “seminal”, “groundbreaking”, “outstanding contributions”, “fundamental”, “pioneering”, “comprehensive” “having long-term, significant impact”, and “the groundwork for all subsequent research”. All of Prof. Wilson’s research papers are characterized by meticulous quality, clarity of exposition, rigorous development, attention to detail, and the highest ethical research standards. Some of the most prominent researchers in the simulation field say they were inspired in their own written and oral expositions by Prof. Wilson’s engaging, stylish rigor.

Prof. Wilson has also contributed broadly to simulation practice in healthcare, logistics, production, the textile industry, and biomechanics. His projects were described in one letter as “great illustrations of how to apply ‘state-of-the-art’ simulation methodology to real-life problems in a non-trivial way. They are important for the advance of simulation practice in operations research and management sciences.”

Prof. Wilson has advised and co-advised over 30 Ph.D. and 40 MS students, at NCSU and elsewhere. Eight of his doctoral students have won awards for their dissertation research. His students and co-advisors commented on Wilson’s dedication, relentless pursuit of excellence, and unprecedented attention to technical and expository details.

Prof. Wilson has received numerous awards for teaching excellence including: the C. A. Anderson Outstanding Faculty Award from NCSU student organizations and the UTC Excellence in Teaching Award from the NCSU College of Engineering. He was also elected to the NCSU Academy of Outstanding Teachers.

In disseminating knowledge, Prof. Wilson has provided excellent written guides for good research writing, reviewing technical papers, and on science and engineering ethics. He is a living template for outstanding written and oral presentations, described in one letter as exemplifying “clarity and attention to detail. What a pleasure it is to see Jim in action!”

Not content with developing and analyzing his innovative algorithms, Wilson and his colleagues have contributed software to disseminate their methodologies. These too have served as prototypes for simulation methodology software. As one letter puts it: Wilson’s software is the “ ‘gold standard’ [for] implementations against which all later proposed algorithms are tested.”

If Prof. Wilson had not already more than qualified for this honor with his research, practice, dissemination of knowledge, and software, he would have qualified solely by his Service to the Profession and Advancement of the Status or Visibility of the Field. Wilson has been simulation’s premier spokesperson. Some of the accolades in the nominating letters described his representation of the simulation community as “exemplary”, “a pillar”, “terrific ambassador for simulation”, “superb expositor”, “eloquent spokesman”, “logical”, and “humorous”. One letter writer describes himself as always “buoyed by [Wilson’s] oration and entranced by his eloquence”.

Prof. Wilson has assumed some of the biggest leadership responsibilities in simulation, and he is acknowledged by his successors as their role model. His service work is overwhelming and outshines the entire simulation community. He has the reputation as a demanding but exceedingly helpful editor. It is well known that he saved the Simulation Department of Management Science from extinction with his relentless pursuit for and handling of high-quality papers. He has served as area editor, editor-in-chief, and guest editor for numerous top journals. One letter commented: “it’s hard to think of anyone who compares to Jim’s service to the profession. In addition to all these achievements, Jim is a genuinely selfless individual who will go way out of his way to help others,…junior colleagues in particular.” Another states: “Jim has strong opinions on research, invariably for reasons based on clear mathematical or practical grounds, and I respect his views enormously. […] The simulation community is far richer because of Jim’s incredible contributions over the course of a distinguished career.” Wilson’s refereeing work is legendary: doing the work of a co-author without attribution (but given his ferocious style and the depth of his reviews, hardly anonymously).

Finally, Prof. Wilson is regarded as the single individual most responsible for the continuing recognition of WSC as the premier simulation conference in the world. He has held every position in the program committee structure. In 2005, he received the WSC Board of Directors Award, after which the award was renamed “The James R. Wilson Board of Directors Award”. One letter writer gives an example: “The Winter Simulation Conference… was in dire financial straits … in the aftermath of the 9/11/2001 attacks. Jim (and others) organized an effort … to maintain the financial viability required for WSC to continue… It is difficult to imagine the state of our field today, in the absence of [the] WSC.” This conference would not have had the opportunity to flourish as it has without Jim’s leadership. When we needed a leader most, Wilson stepped up. He was the guiding force and the inspirational and operational founder of the Fund to support the WSC, as well as the simulation archives at NCSU and the “pioneers of simulation” internet series.

The adjectives used in Prof. Wilson’s nominating letters are a thesaurus of synonyms for excellence. However, the one adjective that resonates throughout is “generous”. No single person has selflessly had more influence in the quality and integrity of simulation than Prof. James R. Wilson.

Perhaps the Selection Committee’s sentiments are best expressed in the words of one of the nomination letters: “Jim is one of those rare individuals who have contributed in so many different ways to the simulation community that it is difficult to imagine what this community would look like, in the absence of those efforts. I cannot imagine an individual more deserving of our field’s Lifetime Professional Achievement Award than Jim Wilson.”

2019 LPAA Selection Committee:

Russell Cheng

David Goldsman

Lee Schruben (Chair)

James O. Henriksen Receives the 2018 Lifetime Professional Achievement Award

Left to right: James O. Henriksen, Robert G. Sargent

The Lifetime Professional Achievement Award is the highest honor given by the Institute for Operations Research and the Management Sciences’ (INFORMS) Simulation Society. The purpose of the award is to recognize major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on computer simulation.

The selection committee, consisting of Russell Cheng (Chair), Marvin Nakayama, and Lee Schruben, is pleased to select James O. Henriksen for the INFORMS Simulation Society's 2018 Lifetime Professional Achievement Award. Jim is the founder and CEO of Wolverine Software, which was established in 1976 and is devoted to providing simulation software to the simulation community.

To be chosen for this award, an individual’s contributions may be in one or more of the following areas: development of software or hardware, contributions to research, service to the profession, contributions to practice, dissemination of knowledge, and advancement of the status or visibility of the field. Jim has made significant and sustained contributions in all of these areas. We next summarize his contributions to the six areas.

Area 1. Development of Software or Hardware. Jim has made numerous contributions to simulation software. He made corrections to IBM’s GPSS software while employed by the University of Michigan Computer Center (part-time 1967-1968 and full-time 1970-1974). Next, Jim was the project manager for the development of CACI’s Univac 1108 version of Simscript II.5 (1974-1975). Jim then established Wolverine Software (1976) for developing simulation software. He first developed GPSS/ H for IBM mainframe computers. The first version released in 1977 had numerous improvements over the other commercial versions of GPSS then available including being compiled instead of interpreted, having much faster run-times for executing models, and having additional modeling features. GPSS/H soon dominated the market for GPSS. Later versions of GPSS/H were developed for various types of computers. GPSS/H continues to be used as a simulation language world-wide. Jim next developed Proof Animation, which was introduced in 1989 as one of the first 2-dimensional simulation animation software products. Later versions were developed including 3-dimensional animations. Jim introduced in 1995 the Simulation Language eXtensible, SLX, as a multiple-layered software simulation product.

Area 2. Contributions to Research. Jim’s research has been primarily directed at developing practical ways to make simulations run faster, to model, and to develop models faster. One of Jim’s major research areas has been and continues to be event-lists algorithms. He has developed perhaps the best algorithms for executing discrete-event simulations based on his research into the statistical underpinnings of event-list behavior. Jim has investigated the “best ways” to model specific systems, such as conveyor systems, using different world views. He has also researched and developed tools to model systems faster, such as debuggers and animation; and furthermore developed what a simulation environment should contain. Additionally, he has developed a new simulation language SLX based on his knowledge gained through years of research, simulation software development, and simulation model development.

Area 3. Service to the Profession. Jim has performed considerable professional service, such as refereeing numerous papers for a variety of journals and conferences. But foremost has been his notable service to the Winter Simulation Conference (WSC). He served as Business Chair of the 1981 WSC, the General Chair of the 1986 WSC, a keynote speaker at the Twenty-Fifth anniversary of WSC (1992), a Titan speaker at the 2006 WSC, one of the panelists to select the Landmark Papers for the Fortieth WSC (2007), and the ACM/SIGSIM representative to the WSC Board of Directors from 1987-1990. Also, Jim was the initiator of having exhibits at WSC, which started in 1984, and which has become an integral part of WSC ever since.

Area 4. Contributions to Practice. Jim through Wolverine Software has provided the simulation community commercial simulation products (GPSS/H, Proof Animation, and SLX) that push the “state-of-the-art” and are “efficient” in a variety of ways including computationally and ease of use. He has made some fifty presentations at WSC that include how to model, how to use specific simulation software, and how specific simulations work. Jim has advised many users of his company’s software how to model “difficult situations” and how to model to avoid excessively long model execution times. Also, while Jim was in the U.S. Army, he did simulations regarding the Safeguard Antiballistic Missile System.

Area 5. Dissemination of Knowledge. Jim taught simulation along with other computer science courses as a Teaching Assistant at the University of Michigan and as an Adjunct Professor at Virginia Tech Northern Virginia Center. He has published papers in Operations Research, Journal of Simulation, and a variety of conference proceedings including several WSC Proceedings. Jim has made numerous presentations to a variety of audiences and has taught classes regarding his company’s simulation products.

Area 6. Advancement of the Status or Visibility of the Field. Jim has promoted simulation as a problem-solving method to many companies and government organizations. His development of GPSS/H that executed much faster than other GPSS Languages and had additional modeling features helped remove the image that simulation had for many years as being a “method of last resort.” Jim was selected to record two videos for the Computer Simulation Archive, a widely viewed collection covering the history of the field.

Support Letters. The support letters for Jim’s nomination emphasized the importance of his numerous contributions to the simulation community. Perhaps of equal significance are the comments made about how Jim is an extraordinary person.

“most noteworthy to me, is his tireless and truly selfless service to the simulation community”;
“as a non-academic, Jim was not required or pressured to teach or be involved with students, but he did so anyway”;
“he is one of the giants in the field”; and
“he is one of the finest individuals whom I have ever met.”

In conclusion, the selection committee is honored to have been able to select James O. Henriksen as the 2018 Lifetime Professional Achievement Award recipient.

Lee W. Schruben Receives the 2017 Lifetime Professional Achievement Award

Left to right: Lee Schruben and Russell Cheng.

The Lifetime Professional Achievement Award is the highest honor given by the Institute for Operations Research and the Management Sciences’ Simulation Society. The purpose of the award is to recognize major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on computer simulation.

The selection committee, consisting of Marvin Nakayama (Chair), Bruce Schmeiser, and Russell Cheng, is pleased to select Lee W. Schruben for the INFORMS Simulation Society’s 2017 Lifetime Professional Achievement Award.

To be chosen for this award, an individual’s contributions may be in one or more of the following areas: research, practice, knowledge dissemination, software or hardware development, professional service, and field status or visibility advancement. A UC Berkeley Chancellor’s Professor and a Fellow of INFORMS, Lee has made significant and sustained contributions in all of these areas, as detailed next.

Area 1. Contributions to research. As one of the few researchers who has received the I-Sim Outstanding Publication Award multiple times, Lee has forged numerous fundamental advances over a broad range of research topics throughout his illustrious career. As one support letter noted, these include “experiment design for pseudo-random number assignment; the coverage function; tests for initialization bias; standardized time series; frequency-domain output analysis; event graphs; input uncertainty; and retrospective optimization as areas for which his seminal paper or papers sit at the base of a huge follow-on literature by other scholars. … What distinguishes Lee ... is the sheer number of breakthrough ideas that he has contributed.” The many other support letters similarly laud Lee’s groundbreaking work. In one letter: “Since the 1970s, Lee has been the most creative researcher in our field.” In another: “Lee is distinguished as one of the few simulation researchers who have made contributions of fundamental importance to both simulation analysis and simulation modeling.” Yet another proclaims: “What is particularly nice about all of this fine theoretical research is that it has direct applications to the real world.”

Area 2: Contributions to practice. Lee has a long and consistent record of promoting and influencing the practice of simulation through his extensive collaboration with the industry. He has been a consultant for nearly 20 companies, including Applied Materials, General Electric, and General Motors. Moreover, Lee has for many years been affiliated with SEMATECH, a research and development consortium, which a 2003 National Academies Report states has had significant impact on the U.S. semiconductor manufacturing industry. More recently, Lee has been involved in projects with the pharmaceutical industry. Lee’s work on event graphs directly led to the creation of a software package called SIGMA, which has had a substantial influence on simulation practice and in teaching simulation modeling. Lee's SIGMA-influenced technology led to Bio-G, a Berkeley student-led startup. Founded in 2007, its clients have included AstraZeneca, Merck, Genentech, Bayer and others.

Area 3: Dissemination of knowledge. Lee has had important dissemination activities beyond his publications, books and consulting. One great impact is his extensive teaching, including twelve different courses at Cornell and seven at Berkeley. For decades Lee has spoken at professional conferences, especially INFORMS and the Winter Simulation Conference. He has also been a leader in charting our field’s future, through keynote presentations at various conferences and his Titans talk at the 2011 WSC.

Area 4: Development of software and hardware. His simulation software SIGMA is used at universities worldwide. As one letter writer explains, it promotes “transparent teaching of modeling and simulation in a language-free fashion enabling the students to focus on the fundamentals rather than the particular characteristics of a specific simulation package.” This software was recognized as one of EDUCOM’s 101 Computing Education Success Stories.

Area 5: Service to the profession. Lee has held various offices for TIMS College on Simulation and Gaming, the precursor to I-Sim. He has served in editorial positions at important journals, including Operations Research, ORSA Journal of Computing, Operations Research Letters, and Simulation. He also chaired the ORIE department at Berkeley. As one letter states “Lee has been instrumental in ensuring the livelihood of the profession, by mentoring future generations and honoring the accomplishments of senior members of the community”.

Area 6: Advancement of the status or visibility of the field. Lee’s early years of careful research papers solidified simulation as an honorable research area. He has been an international presence for decades, and many of Lee’s former Ph.D. students are current leaders in the simulation and operations-research communities. As one letter writer notes, “In summary, I find Lee’s body of work to be the most creative of all researchers in the analysis methodology world of stochastic simulation; he is universally identified as having been at the very top of the field over the course of his long career. Analysis methodology would look very different without him.”

In conclusion Professor Schruben’s contributions in all six areas recognized by the award have been truly outstanding. The selection committee is delighted to be able to select him as an eminently worthy recipient of the LPAA. A video of Professor Schruben’s speech for this award is available via the link: 2017 I-Sim LPAA - YouTube.

Russell Cheng Receives the 2016 Lifetime Professional Achievement Award

The Lifetime Professional Achievement Award is the highest honor given by the Institute for Operations Research and the Management Sciences’ Simulation Society. The purpose of the award is to recognize major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on computer simulation.

The selection committee, consisting of Douglas Morrice, Marvin Nakayama, and Bruce Schmeiser, is pleased to select Russell C.H. Cheng for the INFORMS Simulation Society's 2016 Lifetime Professional Achievement Award.

To be chosen for this award, an individual’s contributions may be in one or more of the following areas: research, practice, knowledge dissemination, software or hardware development, professional service, and field status or visibility advancement. Russell has made significant and sustained contributions in all of these areas. We summarize all six areas here.

Area 1. Research: Russell first published in 1970. His first simulation paper, “A note on the effect of initial conditions on a simulation run,” was published in 1976, forty years ago. Since then, Russell has been a prolific and seminal contributor to the simulation methodology literature in numerous areas. Quoting the taxonomy used in the nomination document, “Among the 130 publications...there are several strong and influential research threads, including random-variate generation, input modeling, variance reduction, metamodeling, input uncertainty, factor screening, design of experiments for queueing simulation, and optimization via simulation.” Quoting from a supporting letter, “Russell never ceases to amaze me with his ingenuity, his playful curiosity and his uncanny knack of asking what sound like the simplest of questions yet get right to the heart of the problem. He also makes research fun and interesting, as anyone who has heard him speak will testify.”

Area 2. Practice: Again, from the nomination document, “These (research threads) are accompanied by a substantial number of application-driven papers that employ simulation to address problems in manufacturing, telecommunications, revenue management, air traffic control, emergency services and combat. One distinguishing feature of these applications is how many of them employed simulation for the difficult task of real-time control, rather than system design.” From a supporting letter, “he is also one of those rare guys whose work ultimately gets used by practitioners.” Another supporting letter says that within the past fifteen years, “He has worked with a very diverse set of organisations including Shell, as part of a PhD project; Ford, working on input modelling for assembly lines; the World Health Organization, modelling tuberculosis and HIV; the UK Defence Science and Technology Laboratories, working on battle simulations; the UK Fire Service in which he worked to determine the optimal deployment of fire engines; and EURO Control, the European Air Traffic Control organisation, for whom he used a discrete event simulation model to test scheduling strategies for aircraft.”

Area 3. Knowledge Dissemination: Russell has been an invited speaker or an active member of the WSC program committee virtually every year for the past twenty-seven years. Editorially, he has actively served several journals, including TOMACS, the Journal of Simulation, the International Journal of Simulation: Systems, Science and Technology, and Operations Research Letters. His book, Non-Standard Parametric Statistical Estimation, will appear shortly.

Area 4. Software and Hardware Development: In addition to his many software codes arising from his research (available online), a nominator provides the example that Russell “spent a number of years designing marine simulators for pilots to use to practice manoeuvring ships around the world’s major harbours, all using DOS screens and very basic graphics.”

Area 5. Professional Service: Russell's list of service roles is long. In 2007, he received the I-Sim Distinguished Service Award. In the United Kingdom, Russell has played a significant role in simulation societies' leadership, including being General Secretary of the United Kingdom Simulation Society (1991-1997) and then Chairman (1997-1999). He was a Board Member of EUROSIM, the Federation of Simulation Societies in Europe (2000-2005).

Area 6. Field Status or Visibility Advancement: As a start, Russell has graduated twenty-two Ph.D. students. From a supporting letter, “To the degree that our community now has a significant international presence, Russell can take a good measure of the credit” and from another supporting letter, “Russell has been key to maintaining the mathematical basis of simulation within the Operational Research community and to introducing statisticians to the interesting problems of simulation.”

Russell's being a Fellow of the Royal Statistical Society and Fellow of the Institute of Mathematics and its Applications also reflects well on our simulation community.

Beyond these six official areas, it is no surprise that phrases such as “Russell’s unassuming and humble nature” arise repeatedly in the nomination and supporting letters. Russell has been influential in developing our simulation community's enviable collegiality while maintaining high standards.

From two other supporting letters, we have summary statements, “Russell is truly one of the giants of simulation in terms of scholarship, teaching, and service; and his impact in these areas has been profound and tremendously beneficial to all of us in our field.” And “Russell Cheng’s contributions to the field of computer simulation are remarkable not only for their scope, depth, and impact, but also for the extended period of time over which that impact has been sustained.” The selection committee is honored to present the INFORMS Simulation Society's 2016 Lifetime Professional Achievement Award to Russell Cheng. A video of Professor Cheng’ speech for this award is available via the link: 2016 I-Sim LPAA - YouTube.

Bernard P. Zeigler Receives the 2015 Lifetime Professional Achievement Award

Left to right: Douglas Morrice and Bernard Zeigler.

The award committee, consisting of Sigrún Andradóttir, Douglas Morrice, and Bruce Schmeiser, is pleased to select Professor Bernard P. Zeigler for the INFORMS Simulation Society 2015 Lifetime Professional Achievement Award.

To be chosen for this award, an individual’s contributions may be in one or more of the following areas: research, practice, knowledge dissemination, software or hardware development, professional service, and field status or visibility advancement. Professor Zeigler has made significant and sustained contributions in all of these areas for over 40 years.

Starting in the 1960’s and 70’s, his research on modeling formalisms grounded in general systems theory provided an overall framework for the development of simulation programming languages. One of his nominators points out as “especially influential” the concepts of hierarchical modeling, modular modeling, the separation of model, simulator, and experimental frame, and the modeling formalism Discrete Event System Specification (DEVS) for discrete event simulation programming languages. All his nominators point out that since his research was so fundamental to simulation modeling, it was leveraged by Professor Zeigler and many others on problems in simulation programming language development, simulation verification and validation, and high level architecture for distributed computer simulations. His work has also been applied across a diverse number of fields including the military, forestry, biology, and healthcare.

Regarding knowledge dissemination, it is difficult to match Professor Zeigler’s record. Based on the generality of his work, several of his nominators point out that he has made several seminal contributions in the fields of system simulation, computer science, and systems engineering. Professor Zeigler's hundreds of scholarly publications in journals, proceedings, and books make him one of the most highly cited scholars in our field. Of his book Theory of Modeling and Simulation: Integrating Discrete Event and Continuous Complex Dynamic Systems (first edition, 1976; second edition, 2000), which has received close to 5000 citations on Google Scholar, a nominator writes “In the past 50 years, no other single publication in the simulation literature has had such a large impact on both the practice and theory of system simulation.” Another one of his books Multifaceted Modelling and Discrete Event Simulation (1984) received the 1988 TIMS College on Simulation Outstanding Publication Award. In addition, Professor Zeigler has given dozens of keynote talks and plenary sessions at conferences and meetings worldwide. Over his career, he has advised over 40 doctoral students with an almost even split between academic and non-academic placements. Lastly, many of the nominators considered Dr. Zeigler’s works classics and required reading for all their Ph.D. students.

Professor Zeigler has served on nine editorial boards including as Editor-in-Chief of SIMULATION: Transactions of The Society for Modeling and Simulation International (1995-2000) and founding editor of Journal of Defense Modeling and Simulation (2003-2008). The high quality of his service is captured in the following comment by one of his nominators “I refereed numerous papers for Professor Zeigler …, and I was profoundly impressed by his conscientious service to the readers and authors of both these journals. An editor-in-chief has to serve numerous constituencies with conflicting interests, and Professor Zeigler has provided the ideal role model for such a position while significantly advancing the journals under his editorship.”

The arguments for Professor Zeigler’s contribution to the advancement of the status or visibility of the field are nicely summarized by one nominator who states “He (Professor Zeigler) provided the first theory … for simulation … Because his theory is based on general system theory, he is able to promote simulation into larger fields such as Artificial Intelligence and relate it to other types of modeling.”

Among his many awards and honors, Professor Zeigler was named an IEEE Fellow in 1995 and received the Society for Computer Simulation’s McLeod Founder’s Award in 2000, both in recognition of his contributions to discrete event simulation.

Taken together, Professor Zeigler’s contributions to the field of computer simulation have been broad, impactful, and sustained. The selection committee is honored to present Professor Bernard P. Zeigler with the INFORMS Simulation Society 2015 Lifetime Professional Achievement Award. A video of Professor Zeigler’ speech for this award is available via the link: 2015 I-Sim LPAA - YouTube.

Bruce Schmeiser Receives the 2014 Lifetime Professional Achievement Award

Left to right: Bruce Schmeiser and Susan Sanchez.

The INFORMS Simulation Society (I-Sim) presented its 2014 Lifetime Professional Achievement Award (LPAA) to Professor Bruce Schmeiser of Purdue University. A presentation of the award took place on December 8, 2014, during the opening session of the 2014 Winter Simulation Conference (WSC) in Savannah, Georgia; and an extended re-presentation of the award took place on December 9, 2014, during the I-Sim business meeting held at WSC'14. A video of Professor Schmeiser’ speech for this award is available via the link: 2014 I-Sim LPAA - YouTube.

The LPAA is the highest honor given by I-Sim. The purpose of the award is to recognize major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on computer simulation. In 2014 the award selection committee consisted of Susan Sanchez (Naval Postgraduate School), Sigrun Andradottir (Georgia Tech), and Douglas Morrice (University of Texas--Austin), with Susan Sanchez serving as the chair of the committee.

Over the course of a career spanning forty-three years, Bruce Schmeiser has made path-breaking contributions to the theory and practice of computer simulation, including the fields of random variate generation, input modeling, output analysis, efficiency improvement (variance reduction), stochastic root finding, simulation optimization, and the development of simulation-related algorithms and software. Bruce is widely recognized for his excellent conference presentations as well as for his remarkable accomplishments as a classroom teacher and mentor. During his career, he has mentored 20 PhD students, taught thousands of students in his courses, and dedicated himself to the purpose of passing on his extensive knowledge of the field to others.

Beyond these technical achievements, for the past five decades Bruce has served the international simulation community in leadership and editorial positions of great responsibility. By his leadership of I-Sim and WSC, Bruce has played a pivotal role in the growth and development of these institutions, thereby substantially advancing the status and visibility of the simulation field at a critical time in its development. Through his service on editorial boards of numerous archival publications of INFORMS, the Institute of Industrial Engineers (IIE), the American Statistical Association (ASA), and the American Society for Quality (ASQ), Bruce has played a similarly vital role in the establishment and advancement of the simulation literature.

In the letters of support, Bruce is described as:

“a true scholar, always generous with his time and ideas;”
one who “has devoted a great deal of time to the general encouragement of junior researchers entering the field, and in helping them think through the key research and teaching challenges of our discipline;”
“an important role model…in how one should conduct oneself in research and professional service;”
one whose encouragement and mentorship continues well after his students graduate;
a “man of integrity and an exceptional Samaritan who truly cares for others.”

The field of computer simulation is much the better for his contributions and leadership.

Taken as a whole, Bruce Schmeiser's contributions to simulation are striking not only for their scope and impact on the field but also for the remarkably long time period over which that impact has been sustained in all of its dimensions. It was with great pride that the selection committee presented to him the 2014 Lifetime Professional Achievement Award of the INFORMS Simulation Society.

Peter Welch Receives the 2013 Lifetime Professional Achievement Award

Left to right: Barry L. Nelson and Peter Welch.

The award committee, consisting of Barry L. Nelson, Sigrún Andradóttir, and Susan Sanchez, are pleased to present the 2013 Lifetime Professional Achievement Award to Dr. Peter Welch.

In the course of a career spanning sixty-two years, Peter has made contributions of fundamental importance not only in the field of computer simulation but also in the broader fields of applied mathematics, applied statistics, computer science, and operations research. Since the mid-1970s Peter has made groundbreaking contributions to the theory and practice of computer simulation, to the dissemination of knowledge in that field, and to the development of simulation-related software systems. For the past three decades Peter has also served the international simulation community in editorial and administrative positions of great responsibility. By his yeoman service to the INFORMS Simulation Society and the Winter Simulation Conference during the period 1994–2011 as the founding webmaster for those institutions, Peter has substantially advanced the status and visibility of the simulation field at a critical time in its development.

Donald Iglehart Receives the 2012 Lifetime Professional Achievement Award

Left to right: Barry L. Nelson and Donald Iglehart.

The Lifetime Professional Achievement Award is the highest honor given by the Institute for Operations Research and the Management Sciences’ Simulation Society. The purpose of the award is to recognize major contributions to the field of simulation that are sustained over a professional career involving, some combination of

Research and Dissemination of Knowledge;
Service to the Profession;
Practice; and
Advancement of the Status or Visibility of the Field.

The award committee, consisting of Reuven Rubenstein, Averill Law and me, are please to present the 2012 Lifetime Professional Achievement Award to Donald Iglehart, Professor Emeritus of the Department of Management Science & Engineering at Stanford University.

Don is being honored for his foundational work on recognizing and exploiting the underlying stochastic structure of simulation as a means of producing enhanced simulation methodologies; for his ability to clearly organize and articulate deep theory in his presentations and writing; and for educating Ph.D. students who have had, individually and cumulatively, a profound impact on simulation education and research. It is no exaggeration to say that Don Iglehart’s contributions made simulation a respectable research discipline in some circles of the operations research community.

Don is a member of the National Academy of Engineering, a winner of the John von Neumann Theory Prize, and a Fellow of INFORMS and the Institute of Mathematical Statistics.

Peter A.W. Lewis Receives the 2011 Lifetime Professional Achievement Award

The Lifetime Professional Achievement Award is the highest honor given by the INFORMS Simulation Society. The award recognizes major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of these contributions on the field. The 2011 LPAA Selection Committee consisted of Averill M. Law (chair), Reuven Rubinstein, and Enver Yücesan.

This year’s winner is Dr. Peter A.W. Lewis (1932-2011), who was Distinguished Professor of Statistics and Operations Research at the Naval Postgraduate School. He was a leader in the fields of computer simulation, applied statistics and probability, and operations research. Peter’s work on simulation theory and methodology encompassed the areas of input modeling (time-series models and non-stationary point processes), random-number generation, variance-reduction techniques, and output-data analysis (regenerative method and quantile estimation).

Peter’s service to the international simulation community included persuading the American Statistical Association (ASA) to become a sponsor of WSC in the mid-1980s, and then serving on the WSC Board of Directors as ASA’s representative from 1986 to 1989. A common theme running through the comments about Peter Lewis by many of his colleagues and former students is his extraordinary influence on their professional careers and his steadfast encouragement and support of their work.

Peter was elected Fellow of the International Statistical Institute, the Institute of Mathematical Statistics, and the ASA.

Reuven Rubinstein Receives the 2010 Lifetime Professional Achievement Award from the INFORMS Simulation Society

Left to right: Enver Yucesan, Reuven Rubinstein, Peter Haas

The Lifetime Professional Achievement Award is the highest honor given by INFORMS Simulation Society. The award recognizes major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on the field.

The LPAA Selection Committee consists of Enver Yücesan (chair), Richard E. Nance, and Averill M. Law. This year’s winner of the LPAA is Professor Reuven Rubinstein of the William Davidson Faculty of Industrial Engineering and Management at Technion. Professor Rubinstein has received his PhD in Operations Research at Rigas Polytechnical Institute in Latvia in 1969. He has joined Technion in 1973. Over the years, he has held many visiting positions in Europe, in North America, in South Africa, Japan and New Zealand. He has served as an editor in Stochastic Models, Methodology and Computing in Applied Probability, and Annals of Operations Research.

“Professor Rubinstein has been a pivotal figure in the theory and practice of simulation as we know it today. His career reflects a high level of creativity and contribution, with a willingness to explore new areas and an amazing ability to suggest surprising new avenues of research and to influence subsequent work.”

Averill M. Law Receives the 2009 Lifetime Professional Achievement Award from the INFORMS Simulation Society

Left to right: Richard Nance and Averill Law

Averill M. Law, President of Averill M. Law & Associates, received the 2009 Lifetime Professional Achievement Award from the INFORMS Simulation Society. The award was presented at the opening session of the Winter Simulation Conference, which was held on December 14, 2009 in Austin, TX.

He is best known for his textbook Simulation Modeling and Analysis, which is now in its fourth edition. (The first three editions were co-authored with W. David Kelton.) It is arguably the all-time, most-successful book on simulation with more than 125,000 copies in print, and widely used in university courses, by simulation practitioners, and for self study.

Dr. Law has been the leading educator on simulation methodology and practice since 1977, having presented more than 475 short courses on all aspects of simulation in 18 countries, and attended by 7000 practitioners, faculty members from leading universities, and graduate students alike. He also taught simulation for 17 years at the University of Wisconsin-Madison and the University of Arizona.

He has made significant research contributions in many areas of simulation, such as output data analysis, comparing alternative system configurations, variance-reduction techniques, selecting input probability distributions, model validation, and manufacturing-system analysis. This research was funded by the Office of Naval Research, the Defense Modeling and Simulation Office, the Navy Modeling and Simulation Office, and the National Institute of Standards and Technology, and was published in journals such as Operations Research, Management Science, Naval Research Quarterly, and Communications in Statistics. His paper "Statistical Analysis of Simulation Output Data" was the first invited feature paper on simulation to appear in a major research journal.

He has been a long-time supporter of the Winter Simulation Conference, having presented at least one tutorial or paper every year since 1976.

Richard E. Nance Receives the 2007 Lifetime Professional Achievement Award from the INFORMS Simulation Society

Left to right: Robert Sargent, Richard Nance and Jack Kleijnen

Professor Emeritus Richard E. Nance of Virginia Tech was presented with the INFORMS Simulation Society's highest honor, the Lifetime Professional Achievement Award (LPAA) at this year's Winter Simulation Conference, December 9-12, 2007, Washington, D.C.

Dick has made numerous outstanding contributions to the simulation profession (and related fields) over his thirty-five plus years as a professional. He was one of the foremost leaders in bringing simulation into the leading professional journals. He was the individual who brought simulation into IIE Transactions and into Operations Research when he included simulation in the departments (areas) that he served as department/area editor for these two journals. This led to individual departments (areas) being established for simulation only in these journals. Dick also initiated the establishment of ACM TOMACS and served as the first Editor-in-Chief. In addition, Dick has served on several editorial boards and as associate editors for a number of journals; and as a co-editor of special journal issues on simulation.

Dick has also made major service contributions beyond his editorial work. He served as President of what is now called the INFORMS Simulation Society and was a WSC Board Representative. He served as the program chair of WSC 1990 and was one of the Founding Trustees of the WSC Foundation. For ACM, Dick was Chair of SIGSIM, Chair of SIGIR, and Chair of numerous committees.

Dick has also made major contributions in research as shown through his publications and his work with students; in practice through his work with the U.S. Navy and consulting; in dissemination of knowledge through his teaching, presentations, publications, and editorial work; in development of simulation software through his work in developing modeling environments and the conical framework; and in advancement of the status and visibility of simulation through his society work, editorial work, numerous presentations, and work with a variety of industrial and government organizations.

Dick has received several awards and honors. To mention some, he is a Fellow of ACM; has received service awards from TIMS College on Simulation (what is now called the INFORMS Simulation Society), ACM SIGSIM, U.S. Naval Surface Weapons Center, and the WSC Board of Directors; has received the Military Operations Research Society Medal; and is a member of honor societies. Dick also held the John Adolphus Dahlgren Chair of Naval Computing Systems at Virginia Tech.

The unanimous decision of the award committee was based on Dick's resume and very strong supporting letters from outstanding members of the international simulation community. The committee and letter writers all agree that Dick is an excellent researcher, educator, and leader of the international simulation community who is well-worthy of the Lifetime Professional Achievement Award. As one letter writer noted, Dick is truly a "giant of simulation."

Jack. P.C. Kleijnen Receives the 2005 Lifetime Professional Achievement Award from the INFORMS Simulation Society

Left to right: Lee Schruben and Jack Kleijnen

Professor Jack. P.C. Kleijnen of Tilburg University, the Netherlands, was presented with the Informs Simulation Society's highest honor, the Lifetime Professional Achievement Award at this year's Winter Simulation Conference, December 4th through 7th in Orlando Florida. Unrelated to this award, there was a special research track in tribute to Professor Kleijnen at the Conference, where he was further recognized by being a speaker at the Titan's of Simulation honorary assembly.

Professor Kleijnen has excelled in many of the criteria that are qualifications for this award and made significant contributions to the field of simulation and in other areas for more than 40 years. His published work includes 6 books and almost 200 papers, many receiving awards. Jack was described in one of the nomination's supporting letters as "a true pioneer in simulation research". Another endorsement letter said: "keeping track of Jack Kleijnen's research is close to a fulltime job."

Professor Kleijnen has also distinguished himself in his service to the profession. Jack is the only person in recent memory to have received an Operations Research Meritorious Service Award two years in a row for his editorial and refereeing work - in two different areas!

All the writers of supporting letters mentioned Professor Kleijnen's direct and personal influence on their careers. One of Jack's most notable traits is his consistent energy and infectious enthusiasm for simulation. As noted in one letter, Jack has a "downright charming and genuine fascination with new ideas." All who know Jack will agree with the remark in another supporting letter that points to Jack's constant level of enthusiasm and prolific work both within simulation and in other areas, calling him simulation's "great ambassador".

George S. Fishman Receives the 2004 Lifetime Professional Achievement Award from the INFORMS Simulation Society

Left to right: George S. Fishman and Robert G. Sargent

George S. Fishman, professor emeritus of operations research in The University of North Carolina at Chapel Hill, received the 2004 Lifetime Professional Achievement Award from the INFORMS Simulation Society. The award was presented at the opening session of the 2004 Winter Simulation Conference, which was held in Washington, D.C., on December 6, 2004. The award selection committee for 2004 was chaired by Robert G. Sargent (Syracuse University), with members Thomas J. Schriber (University of Michigan) and Lee W. Schruben (University of California, Berkeley).

The highest honor of the INFORMS Simulation Society, the Lifetime Professional Achievement Award is given at most annually to recognize an individual for major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on computer simulation. An individual’s achievements may fall in one or more of the following categories:

contributions to research,
contributions to practice,
dissemination of knowledge,
development of software or hardware,
service to the profession, and
advancement of the status or visibility of the field.

The period of professional accomplishment for a recipient should normally be at least twenty years.

George Fishman is one of the pioneers in the field of discrete-event stochastic simulation, having inaugurated the use of rigorous approaches to the development of statistical methods for simulation during the 1960s while he was working at the Rand Corporation and simultaneously earning his Ph.D. degree in biostatistics from the University of California at Los Angeles. (He received a master’s degree in economics from Stanford University in 1963 and a bachelor’s degree in economics from the Massachusetts Institute of Technology in 1960.) After receiving his Ph.D. in 1970, George served on the faculty of Yale University for four years; and in 1974 he joined the faculty of The University of North Carolina at Chapel Hill, where he has spent the rest of his professional career.

George Fishman has made numerous major contributions to simulation research over the past five decades; and in the process he performed a key role not only in shaping the research agenda for the field of simulation but also in setting the standards for high-quality research in the field. In the area of simulation output analysis, George pioneered the use of spectral analysis and the autoregressive method; he cointroduced the regenerative method; he performed groundbreaking analysis of the method of batch means; and he formulated new algorithms for batch means and implemented those procedures in software for large-scale practical applications. In the area of random-number generation, George performed comprehensive empirical analyses of random-number generators; and he introduced new performance measures for evaluating the behavior of those generators. This research stimulated the development of substantially better random-number generators for practical applications. George also made significant contributions to the allied area of (nonuniform) random-variate generation.

Another major focus of George’s research is computational and statistical efficiency in simulation. He introduced new methods for efficiency improvement and variance reduction in the design, execution, and analysis of computer simulation experiments. George has developed several methods for efficient simulation and performance evaluation of stochastic networks, Markov chains, and other probabilistic models that commonly arise in operations research.

George has written six books. Two of these books deserve special comment. His 1973 book, Concepts and Methods in Discrete Event Digital Simulation, was one of the first comprehensive books on all aspects of simulation, providing thorough coverage of such topics as the modeling of systems, developing simulation programs, and analyzing simulation output. His 1996 book, Monte Carlo: Concepts, Algorithms, and Applications, received the 1996 Frederick W. Lanchester Prize from INFORMS as well as the 1997 Outstanding Simulation Publication Award from the INFORMS College on Simulation.

George has disseminated knowledge about simulation well beyond the seventy-plus research articles and the six books that he has written. Over the past five decades, he has presented numerous papers at professional conferences and has given seminars at universities around the world. George has also written several papers on the applications of simulation in a broad diversity of disciplines.

George has performed substantial service to the field of simulation, and for this he received the 1990 Distinguished Service Award from the INFORMS College on Simulation. He served as president of TIMS College on Simulation and Gaming (now the INFORMS Simulation Society) from 1972 to 1974. George served as the first editor of the Simulation Department of Management Science during the period 1978–1987. As the Simulation Department Editor of Management Science, George exercised a decisive influence in establishing the standards for archival research publications in simulation—a highly controversial topic in the late 1970s and early 1980s. He served on the Board of Directors of the Winter Simulation Conference (1978–1980) and on the Editorial Advisory Board of ACM Transactions on Modeling and Computer Simulation (1989–1992). He has also served on numerous committees of professional societies and international conferences. George Fishman’s contributions to the field of simulation in leadership and service have substantially advanced the field over the past forty-plus years, especially during the 1970s.

George has also been a leader in operations research education. He exerted remarkable leadership in advancing Operations Research at The University of North Carolina at Chapel Hill, including helping to establish the Department of Operations Research and serving as chair of that department for a decade. George served as the adviser to numerous master’s and doctoral students, and he served on the advisory committees of many more master’s and doctoral students.

In summary, George S. Fishman has made exceptional contributions to the field of discrete-event simulation through his research, dissemination of knowledge, leadership, and service. Several letters of endorsement from distinguished individuals accompanied George’s nomination for the Lifetime Professional Achievement Award. Two themes running through all these letters are that George has had an amazing amount of productivity and that he is a world-class scholar, researcher, and leader in the field of simulation and in the larger fields of operations research and the management sciences. George Fishman’s career epitomizes the highest ideals of the Lifetime Professional Achievement Award of the INFORMS Simulation Society.

Robert G. Sargent Receives the 2002 Lifetime Professional Achievement Award from the INFORMS-College on Simulation

Left to Right: Thomas Schriber and Robert G. Sargent

Robert G. Sargent, Professor Emeritus of Electrical Engineering and Computer Science at Syracuse University, received the 2002 Lifetime Professional Achievement Award from the Institute for Operations Research and the Management Sciences-College on Simulation (INFORMS-CS). The award was presented to Dr. Sargent at the Opening Session of the 2002 Winter Simulation Conference, which was held in San Diego, California, on December 9, 2002.

The Lifetime Professional Achievement Award is the highest honor given by INFORMS-CS, and it is given at most once a year. The award recognizes major contributions to the field of simulation that are sustained over most of a professional career, with the critical consideration being the total impact of those contributions on the field. An individual's contributions may fall in one or more of the following areas:

contributions to research,
contributions to practice,
dissemination of knowledge,
development of software or hardware,
service to the profession, and
advancement of the status or visibility of the field.

The period of professional accomplishment for a recipient of the award should normally be at least twenty years. In 2002 the award selection committee was chaired by James R. Wilson (North Carolina State University), with Thomas J. Schriber (The University of Michigan) in his initial year of service and Julian Reitman (University of Connecticut, Stamford) completing his final year of service on the committee.

Bob Sargent first became involved with discrete-event simulation in the early 1960s as a graduate student at The University of Michigan, where he studied simulation methodology and developed simulation models. After completing his Ph.D. at Michigan in 1966, Bob joined the faculty at Syracuse University and taught simulation there until he retired in the late 1990s. Bob contributed significantly in several areas of simulation during his professional career. He made important research contributions to simulation methodology, many having a practical flavor. His sustained service to the simulation profession is well known and has been formally recognized with several service awards. He disseminated information about simulation and advanced its visibility through numerous presentations and tutorials at major international conferences and through his work with the U.S. Air Force. Bob was also one of the first individuals to initiate the modeling of computer systems for performance evaluation. His most significant professional achievements in simulation are detailed below.

1. Contributions to Research
Bob has made major research contributions in several areas of simulation methodology.

In the modeling area, he coauthored the definitive paper on hybrid analytic/simulation modeling. He made important contributions subsequent to the original development of Event Graph Models, which are graphical representations of the event world view. Bob led the development of Control Flow Graph Models, which are graphical representations of the process world view. He and one of his students later extended these graphical representations by evolving Hierarchical Control Flow Graph Models to facilitate development, maintenance, execution, and reuse of complex simulation models. Bob and another of his students updated and extended the experimental frame concept.
In the area of computational speedup of simulation model execution, he and his students made contributions to event-list processing, the use of associative processors (associative processing), and the use of parallel computers (parallel simulation).
In the output analysis area, Bob's contributions include the following: development of new statistical estimators; a comprehensive theoretical and experimental comparison of confidence interval estimators; creation of a methodology for fitting and validating metamodels that use different types of basis functions; and the development of the cyclic regenerative method.
In the verification and validation (V&V) area, he raised the visibility and understanding of the roles of verification and validation and the distinction between them. He developed a graphical view of how V&V relates to the modeling process, which is known as the "simplified view of the modeling process," and which has become widely used. He and a student developed a statistical framework within which to view validation. He also developed numerous validation techniques, approaches, and methodologies.
In the area of the theory of simulation, he and a student developed a general framework for discrete-event modeling and simulation based on formal logic.

2.Contributions to Practice
Bob was involved with some of the first data collection, data analysis, and modeling of computer systems for performance evaluation. Some of this work is contained in his publications. Much of Bob's research work was directed toward obtaining results that can be used by practitioners. Furthermore, he worked with the U.S. Air Force on military problems, as well as serving on some Department of Defense committees.

3.Dissemination of Knowledge
Bob has been an active disseminator of simulation knowledge to practitioners and researchers alike. He started giving tutorials on "Introduction to Simulation Languages" and "Output Analysis" in the 1970s and later gave tutorials on "Verification and Validation." These presentations were made at Winter Simulation Conferences (WSCs); Symposia on the Simulation of Computer Systems; NATO meetings; joint international conferences of The Institute of Management Sciences (TIMS) and the Operations Research Society of America (ORSA) [now merged to form the Institute for Operations Research and the Management Sciences (INFORMS)]; meetings of local professional societies; and seminars at universities. Bob also disseminated state-of-the-art knowledge on simulation through numerous presentations at conferences and universities around the world. He was a coeditor of the 1976 and 1977 Proceedings of the Winter Simulation Conference; coeditor of a special issue of Operations Research on simulation, (1983, Vol. 31, No. 6); and coauthor of state-of-the-art bibliographies. He was a National Lecturer with the Association for Computing Machinery (ACM) during the period 1985-1989, giving numerous talks on simulation at ACM chapters. In addition, he taught simulation credit-courses at Syracuse University for over thirty years; and he chaired the dissertations of nine Ph.D. students, six of whom did their Ph.D. work in the area of simulation.

4.Development of Software Bob and his students developed prototype simulation systems, including the Hierarchical Modeling and Simulation System-Java (HiMASS-j), to demonstrate the concept and workability of using the paradigm of the Hierarchical Control Flow Graph Model together with visual interactive simulation model building and an updated approach to experimental frames. Some of these developments were done on behalf of the U.S. Air Force.

5.Service to the Profession
Bob made many significant service contributions to the simulation community in a variety of areas. Bob was and still is very active in TIMS/College on Simulation and Gaming, now known as INFORMS-College on Simulation. He held all the offices in the College, including the position of president (1978-1980). He served on most of the College's committees, and was involved in establishing all the awards given by the College.

Bob's contributions in service to WSC over the past four decades deserve special mention. He was the representative of the Institute of Industrial Engineers (IIE) to the conference committee of each annual WSC from 1974 to 1984. Bob was instrumental in initiating the rebirth of WSC in 1976, serving as the Associate Program Chair for the 1976 WSC, and then as the General Chair for the 1977 WSC. He played a key role in the establishment of the WSC Board of Directors; and he drafted a set of bylaws for the WSC Board, coordinating three revisions of that document that culminated in final Board of approval of its by-laws in 1979. Bob also formulated the duties of the various officers of the Board. He continued as the IIE representative to the Board from 1976 to 1984, and he served as Board Chair from 1979 to 1981. Bob has also served various annual WSCs as a track coordinator and session organizer.

Bob's editorial work is commensurate with the other dimensions of his service to the simulation community. He helped establish the Simulation Department of Management Science in the mid-1970s; and then he played a critical role in saving that department from closure on three separate occasions in the late 1970s and the early 1980s. He was the Departmental Editor for Simulation Modeling and Statistical Computing (Research Contributions) of the Communications of the ACM, serving from 1980 to 1985. Bob was involved in establishing the ACM Transactions on Modeling and Computer Simulation (TOMACS); and he served on the TOMACS Editorial Advisory Board from 1989 to 1997. Over the years, he served as a referee for numerous archival journals in the fields of industrial engineering, operations research, and computer science. For the special fiftieth anniversary issue of Operations Research (2002, Vol. 50, No. 1), Bob coauthored an invited article on the past, present, and future of the field of simulation that was titled "Perspectives on the Evolution of Simulation."

Bob service to the simulation community has spanned numerous professional societies and major international conferences. Bob gave the Keynote Address at the 1998 Conference on Simulation and Visualization (in Magdeburg, Germany); and he gave the Doctoral Colloquium Keynote Address at the 2000 WSC. He was a Director-at-Large of the Society for Computer Simulation (now the Society for Modeling and Simulation International, or SCS) from 1984 to 1987; he was a member of the Executive Committee for Simulation of the Institute of Electrical and Electronics Engineers (IEEE) Computer Society for several years; and he was an active member of the ACM Special Interest Group on Simulation (SIGSIM), serving on committees and performing various tasks. Bob organized numerous sessions on simulation at various national and international meetings. Bob has also provided service to the National Science Foundation, much of which had to do with the field of simulation. In addition, he served various professional societies in areas other than simulation. For his service work, Bob received awards from the following organizations: ACM; IIE; the WSC Board of Directors; and the INFORMS-College on Simulation (in particular, he received the College's Distinguished Service Award in 1988).

6. Advancement of the Visibility of Simulation
Over the past four decades, Bob has increased the visibility of simulation through his numerous presentations at a broad range of professional meetings-in particular, the national and international conferences of ACM, IEEE, IIE, INFORMS, and SCS-and in his work with the U.S. Air Force, where he promoted simulation as a problem solving technique.

7. Summary
The nomination of Bob Sargent for the INFORMS-CS Lifetime Professional Achievement Award was accompanied by letters of endorsement from ten distinguished individuals who can evaluate authoritatively various facets of Bob's remarkable career. A common theme running through the ten letters of endorsement is that in all his professional activities, Bob has set a standard for uncompromising integrity and a commitment to excellence that many people in the international simulation community have tried to emulate. Perhaps Lee Schruben expressed this sentiment most forcefully in his letter of endorsement:

At critical points in my career and life, he has been the most supportive voice. Above all else, Bob is always the teacher. He is direct but constructive in his criticisms, and with high but attainable standards. Even after losing an argument with Bob, he somehow makes me feel better than before the exchange. In academics, where arrogance and negativity often mask themselves as a commitment to high standards, Bob stands out as positive, able to see and add value. He tries to look for what is right as well as what may be wrong with any new idea. There are several lines of research that I would have abandoned without Bob's encouragement and some that I did abandon, or should have, for lack of it.

If it is possible for someone to be everyone's friend, then Bob has done it by being a best friend to our profession. I am happy to count him among mine. Bob's accomplishments stem from one core value: he cares, and by doing so makes us all care.

Bob Sargent's career epitomizes the highest ideals of the Lifetime Professional Achievement Award of the INFORMS-College on Simulation; and it was with great pride that the selection committee presented the award to him.

Tom Schriber Receives the 2001 Lifetime Professional Achievement Award from the INFORMS-College on Simulation

Tom Schriber

The Lifetime Professional Achievement Award is the highest honor given by the Institute for Operations Research and the Management Sciences (INFORMS)-College on Simulation. Given at most once a year, the award recognizes major contributions to the field of computer simulation that are sustained over a professional career. The winner may qualify based on one or more of the following six areas:

research,
practice,
dissemination of knowledge,
development of software or hardware,
service to the profession, and
advancement of the status or visibility of the field.

In 2001 the award selection committee was chaired by Julian Reitman (University of Connecticut, Stamford), with James R. Wilson (North Carolina State University) in his initial year of service and David Goldsman (Georgia Tech) completing his final year of service on the committee.

Thomas J. Schriber, the winner of this year's award, has made remarkable contributions in all the categories listed above. Tom became involved with discrete-event simulation research when he joined the faculty of the University of Michigan Business School in 1966; and he has subsequently introduced many thousands of people to simulation throughout the world. Tom is perhaps best known for his landmark textbook, Simulation Using GPSS, which was first published in 1974. Also known as the "Red Book," this classic text had 38 printings totaling 40,000 copies during the period 1974-1988; and since 1980 the Russian translation of this book, naturally called the "Red Red Book," has sold over 10,000 copies.

Since the mid-1960s Tom has promoted simulation around the globe-from behind the former Iron Curtain to Chile, Mexico, the Netherlands, Korea, and many other countries. Tom is truly the ambassador to the world for the field of simulation. He loves to teach; and he is particularly highly regarded for his tutorials and national lectures, both in academic and industrial settings. Tom's service to the profession extends to the Winter Simulation Conference, where for many years he served on the Board of Directors as the representative of the Association for Computing Machinery (ACM). He has also been an associate editor for numerous scholarly journals. Tom has made outstanding contributions to simulation research in a broad range of areas, including simulation output analysis, simulation modeling and language development, and the application of simulation to the design and control of production and transportation systems. Tom has disseminated this knowledge at all levels of academia, government, and industry via his many books, speeches, mentoring of students and colleagues, and academic leadership. Tom Schriber's career epitomizes the highest ideals of the Lifetime Professional Achievement Award of the INFORMS-College on Simulation.

Alan Pritsker Receives the 1999 Lifetime Professional Achievement Award from the INFORMS-College on Simulation

Presentation Remarks of David Goldsman

Tonight I would like to honor Alan Pritsker with the presentation of the INFORMS College on Simulation's Lifetime Professional Achievement Award --- here in the informal atmosphere of the College business meeting.

The Award recognizes major contributions to the field of computer simulation that are sustained over a professional career. The winner may qualify based on one or more of six areas:

research,
practice,
dissemination of knowledge,
development of software or hardware,
service,
advancement of the status of the field.

Alan is that rare individual who could have won the Award based on his contributions in *any* of the areas, let alone all six!

Let me start by putting giving some examples showing how longstanding Alan's commitment to simulation has been --- easily over 40 years ---

from fighting to use simulation for research and consulting at Battelle
to teaching and developing simulation languages at ASU
to advancing the state-of-the-art in research and language development at Purdue and Pritsker and Associates
to leading projects of major societal importance.

I will now touch on just a few of the accomplishments that exemplify Alan's impact on our profession.

Leadership in Professional Societies. By his leadership in various professional societies and governmental organizations over the past 40 years, Alan has contributed significantly to the dramatic growth of the field of simulation as well as the larger fields of IE and OR. To this end, Alan was awarded the Frank and Lillian Gilbreth Industrial Engineering Award in 1991. Its citation reads: This award is the highest and most esteemed honor presented by the IIE and recognizes individuals who have distinguished themselves through contributions to the welfare of mankind in the field of industrial engineering. The contributions are of the highest caliber and are nationally and internationally recognized. Alan also enjoys the singular distinction of being the only individual in IIE's history to be honored with a special issue of IIE Transactions on the occasion of that person's retirement --- that issue will be published next year.

Of course, Alan has also served the Winter Simulation Conference in many capacities, most notably as WSC Board representative from IIE and our College over the years.

Leadership in the National Academy of Engineering. The NAE is an organization of national importance and influence --- both on the educational and political sides of things. Alan was the second industrial engineer to be elected to the Academy. He has since served the Academy in many capacities. Perhaps most important to us, he has encouraged the Academy to elect other IE's, and so has directly enhanced the importance of our field on the national level.

Research and Teaching. Alan is recognized world-wide for his advancement of the theory and methodology of discrete and combined simulation, as well as simulation environments. Alan is also widely known for his work in simulation output analysis and variance reduction techniques. Even now, Alan is developing new ranking and selection methods to select the best of a number of alternative simulation scenarios with precise statistical guarantees.

Alan loves to teach and mentor students at all levels. He has also produced a progeny of exceptional Ph.D. students --- among them,

Hank Grant, Southwestern Bell Professor at The Univ. of Oklahoma
Hamdy Taha, University Professor at The Univ. of Arkansas
Gary Whitehouse, Provost, University of Central Florida
Jim Wilson, Chair of IE at North Carolina State
Nick Hurst, General, US Army.

Applications. Alan's work is driven by real-world practice. He has made countless contributions in this regard. Two examples are his work with policy analysis for organ transplantation, and, in the area of manufacturing, real-time factory control.

Over the past five years, Alan has led the development and use of large-scale simulation models of various operations of the United Network for Organ Sharing (UNOS). In particular, the UNOS Liver Allocation Model (ULAM) has been used to compare proposed policies for allocating donated livers to patients awaiting a transplant. This work included state-of-the-art modeling and statistical analysis techniques, resulting in a number of archival publications. But partially on the basis of Alan's extensive analyses of ULAM-generated predictions of the effects of implementing various policies, UNOS made a highly publicized change to its liver-allocation policy in January 1997. In June 1998, Alan testified to Congress on the results of his comparison of the current policy vs. a sickest-patient-first national waiting list; shortly thereafter, Congress authorized the continuation of the current policy for a year pending and independent review by the National Academy of Sciences. This is a remarkable example of the definitive practice of simulation in addressing ultimate questions of life and death.

Many of us would not be here today if it were not for Alan. Just look at this small sampling of the lives he has touched. On the academic side of things, for instance, Bruce Schmeiser might never have decided to go to Purdue if Alan had not been doing simulation there. Jim Wilson would probably have ended up in a different field than simulation. Lee Schruben and David Kelton have told me that they might not have been where they are today without the foundations laid down by Alan. And then additional generations would never have been spawned: Barry Nelson, Keebom Kang, Enver Yucesan; the list goes on and on. On the applied side, Alan was doing things with simulation 25 years ago that have ultimately evolved into the bountiful variety of simulation languages that we see today. His ideas have certainly influenced generations of simulation language developers and modelers.

Clearly, in all ways, Alan has advanced the status of our field, so let's congratulate my wonderful friend on this outstanding achievement.

Julian Reitman Receives First Lifetime Professional Achievement Award from INFORMS-College on Simulation

Left to right: Stephen D. Roberts and Julian Reitman

The INFORMS College on Simulation is pleased to recognize Julian Reitman with its first Lifetime Professional Achievement Award (LPAA). The award was presented during the opening ceremonies of the 1998 Winter Simulation Conference, recently held in Washington, DC. The Selection Committee consisted of Steve Roberts, David Goldsman, and Gordon Clark. The LPAA award, given at most once a year, was established "to recognize major contributions to the field of simulation that are sustained over most of a professional career." Certainly Julian Reitman epitomizes that ideal. His active career in simulation has covered more than forty years, virtually spanning the history of modern computer simulation.

Julian Reitman was on the frontier of simulation application and he pioneered many simulation developments. And he has generally been regarded as one of the "true" founders of the simulation community as we know it.

Almost from the beginning of his career in the late 1940s, Julian was thrust into the world of electronic analog computing and modeling. He was fortunate to make an early transition into the digital world in the 1950s, being asked to create computer and communications systems for airline reservations. This assignment permitted him the opportunity to work directly with complex systems of people and technology.

As with so much of the history of mankind, it is how we handle the confrontation with real problems that is ultimate test of our character. In Julian's case, out of a frustration with limited analysis tools, he "discovered" computer simulation. In fact, it was probably Julian's prodding that caused IBM to make GPSS, its internal simulation language, public. Julian was one of the first, and one of the few, to recognize the value of a "high-level" modeling approach to solving complex systems problems. In the 1960s, he was the leader of one of the first simulation application groups in industry -- at the Norden Division of United Aircraft Corporation.

Throughout the 1960s and into the 1970s, Julian and his team at Norden had a number of remarkable accomplishments. They created many simulation models of real systems: naval vessel performance, anti-submarine warfare, effectiveness of airborne radar, railed automated highways, air traffic control, message switching in communications, yield predication for integrated circuit production, and countless others. Activities were carried out throughout the world. Many of this models were the first such simulation applications and they promoted the tool in a number of ways.

While breaking new ground in simulation applications, Julian became a leading proponent for extensions and enhancements to GPSS that incorporated user features that foretold the future of simulation. Three deserve special mention; (1) memory-management facilities to execute models whose size exceeded physical memory, (2) interactive control of executing simulations with real-time debugging that allowed revision of model logic and data, and (3) animation of executing simulation models and the graphical display of simulation output. Remarkable accomplishments considering that it was 1970!

It would have been easy for Julian to limit his attention to the success of his team and his company, but that is clearly not in his nature. Julian believed that he had an obligation to the profession and to society. In the mid-1960s Julian played a leading role in the establishment of the IEEE Systems, Man, and Cybernetics Group, where he served as chair, was on the administrative committee, was on the Editorial Board of IEEE Press, and an associate editor of two IEEE journals. Julian was named a Senior Life member in recognition of his service to IEEE.

Julian was one of the founders of the Winter Simulation Conference(WSC) first serving as the program chair for the WSC predecessor that was held in 1967. That conference arose out of Julian's concern that simulation applications have an outlet. Julian served as General Chair of the first WSC in 1968, published a proceedings, and established much of the structure and tradition of what we see in today's conference. Julian served in active leadership of the WSC and in 1976 was one of the founding members of the WSC Board, serving until 1985. He has been the longest serving board member representing any society.

Julian was also one of the pioneers in the establishment of the simulation literature. Julian published the first article on simulation to appear in the IEEE general-interest publication in 1974 and numerous articles since then in other journals. He won the best paper award at the Fifth Annual Simulation Symposium in 1972. As an outgrowth of his teaching courses in universities, in plants and locations throughout the world, he ultimately in 1971 wrote one of the first simulation textbooks, destined to be a classic, entitled Computer Simulation Applications: Discrete Event Simulation for Synthesis and Analysis of Complex Systems.

Julian's service to the simulation community continued through the 1980s and into the 1990s. Today he remains active in "retirement" by teaching and documenting the history of science and technology. Julian is quick to remind us all that while there has been considerable advances in the technology of simulation, predictions of performance are often inadequately understood and observed. They are inextricably tied to the human element and that understanding the role of people remains a significant area for future development.

Julian Reitman was among the first, if not the most prominent, to champion of the application of simulation, and this focus on simulation application has been his lifelong passion. Julian's professional contributions to the field of simulation, especially in the application of simulation, are striking not only for their impact on the field, but also for the remarkably long period over which that impact has been sustained.