Celebrating over 70 Years of Modeling and Simulation

The History of The Society for Modeling and Simulation International (SCS)

Over seventy years ago, John McLeod and a group of fellow analog computer users met in November of 1952 at Point Mugu, California to form a Simulation Society. John McLeod proposed the formation of an association “to increase the effectiveness and broaden the application of simulation” with the stated purpose being "to promote the advancement of simulation and allied computer arts.” Originally, society members, who were expert in the use of slide rules, banded together to share techniques for using analog computers. In 1952, John McLeod and other pioneers wanted to reach beyond analog computer concerns and beyond their own field of aerospace, in defining the purpose of their activities. They had the vision to realize that this was simulation, not analog computation, and that simulation was not going to be restricted to aerospace applications. An organization was formed, named the Simulation Council. It was agreed that it would hold monthly meetings organized by a five-member Steering Committee that would change from meeting to meeting. John McLeod of NAMTC, Point Mugu was the first Chairman of the Steering Committee, which also included Rick Anderson of the J. B. Rea Company, Albert Fulton of Hughes Aircraft Co., Walt Mitchell of the Navy Electronics Laboratory (NEL), and Lee Cahn from analog computer manufacturer, Beckman Instruments.

The group agreed to produce a monthly newsletter and John McLeod was appointed editor. This was the beginning of a lifelong commitment for both John and his wife, Suzette, who was appointed Council Secretary. John agreed to pay for the first three issues of the newsletter himself, to see if the idea would fly. John McLeod famously told the story of having trouble producing copies of the original Simulation Council Newsletters on a temperamental mimeograph machine in a bedroom of the McLeod home in Camarillo, California. From time to time the machine would decide to transfer more ink on to its operator than to the paper. Several times John's clothes ended up covered in ink. Always the problem solver, John carried out experiments that established that the ink could be washed from his skin, but not from his clothes. The remedy was obvious and the editor produced several issues of the Newsletter au naturel. The second meeting of the Simulation Council was held at Truman's Restaurant in Westwood, California (north of Los Angeles) on the subject of Function Generators. The meeting attracted an attendance of thirty-seven individuals representing fifteen organizations. The organization remained informal, with no charter, no bylaws, no officers, and no dues - at least for a time.

The history of Simulation Council to Simulation Councils, Inc.
By this time, the activities of the Simulation Council were becoming more widely known and admired. On June 28, 1954, just 18 months after the Simulation Council was formed, the Midwestern Simulation Council met for the first time at the University of Michigan. Dr. Robert M. Howe was appointed Chairman of the new council and the name of the original Simulation Council was changed to the Western Simulation Council. Less than six months later, on November 15, 1954, the Eastern Simulation Council was established at a meeting at the Applied Physics Laboratory, Johns Hopkins University with Harold K. Skramstad of the National Bureau of Standards as its first Chairman.

Considering the difficulties involved in producing the newsletter as well as the growing and more widely distributed readership, a more convenient and effective way of publishing the Newsletter had to be found. The solution was an arrangement, starting with the March 1955 issue of the Newsletter, to publish the newsletter as a regular section in the journal Instruments and Automation (which changed its name to Instruments & Control Systems in February 1959). The last issue of the original newsletter was produced in February 1955.

The years 1955 and 1956 brought further growth in the developing network of councils. Four more councils were established, bringing the total to seven. The South-Eastern Simulation Council was created on September 30, 1955, at a meeting in the Arnold Engineering Development Center in Tullahoma, Tennessee. The Council's first Chair was W. K. McGregor of ARO Inc. This was followed in October 1956 by the Central States Simulation Council, chaired by James A. Pierce of Beechcraft Aircraft.

The organization had now grown to a point that demanded a more formal structure and, on June 3, 1957, the Simulation Councils, Inc. (SCi) was formed as a California non-profit membership corporation by Dov Abramis, George A. Bekey, and Norman L. Irvine. Until 1962 a Board of Directors led by its Chair guided the organization. In 1962 the title of this position was changed to President. The newsletter continued to appear in Instruments and Automation until December 1963. Volume 1, Number 1 of the new journal SIMULATION was published in the Fall of 1963 and was published monthly in two volumes per year until December 2001 when the Society's publications were redesigned. The purpose of the newly incorporated organization was "to promote the advancement of simulation and allied computer arts by sponsoring meetings and informal discussions, by publishing reports of these meetings and papers, and by cooperating with educational and other organizations in activities that contribute to the advancement of simulation and allied arts." Membership in the organization had grown to nearly 2,000 by this time and it has subsequently fluctuated between about 1,400 and 2,000.

The history of SCi to SCS
The early regional council structure of the Society was built around local or regional meetings often devoted to a selected topic and the publication of a monthly newsletter. Local meetings were the rule for the Western Simulation Council, but other regional councils tended to organize regional meetings with several presentations. National meetings were limited to events at the Spring and Fall Joint Computer Conferences. As the organization became more widely distributed, the need for activities and services with a greater national reach became more apparent. This need, which required the network of Simulation Councils to convert itself into a national society, was met first by a switch of emphasis from local and regional meetings to national conferences and, later, by adding new publications.

By 1972 the regional council structure covered not only the entire United States and much of Canada, but had also gained its first foothold in Europe with the creation of the United Kingdom Simulation Council (UKSC) in 1968. The Society was also the co-sponsor of two major annual conferences. A change of name seemed in order, and in 1972 the society started to do business under the new name The Society for Computer Simulation (SCS) although its legal name continued to be Simulation Councils Inc.

Conferences and Publications History
The structural reforms of the 1970s produced an Executive Committee structure with specific VP positions devoted to Publications and to Conferences. In addition to SIMULATION, SCS was producing the Simulation Proceedings series of hard back books, and additional occasional publications such as the Directory of Simulation Software. In 1984 SCS President Walter Karplus launched a new quarterly publication, Transactions of the Society for Computer Simulation, which featured papers of archival quality, in contrast to the more topical and news-oriented material in SIMULATION. Additionally, Publications was responsible for post-conference sales of conference proceedings. This established the pattern for the publication’s operation for the 1980s and 1990s.

Changes also occurred in the conference activities of the society. In the 1970s Lance Leventhal, SCS Technical Editor, proposed a multi-conference format that focuses on selected specialized topics operating as independent mini-conferences within the conference structure. The Western Multi-Conference (WMC) came first, and is still held each January. Next came the Eastern Multi-Conference (EMC), held in the Spring, which later changed its name to the Simulation Multi-Conference (SMC) and changed again in 1997 to the Advanced Simulation Technologies Conference (ASTC).

The multi-conference format has proved very successful. Well-established & strongly-supported topics could be combined with new or more specialized topics that attract less support and benefit from being part of a larger financially viable event. WMC based its early development on the success of its core track on Simulation with Microcomputers in the days when simulations using desktop microcomputers running rudimentary operating systems like CP/M and MS-DOS were a major challenge. EMC was built on the success of the Simulators conferences.

SCS International Growth History
The SCS council structure did not serve members outside North America until 1968 when the United Kingdom Simulation Council (UKSC) was formed and became part of SCi. In August 1964, during the 1964 Congress of AICA (the Association International pour le Calcul Analogique) ­ now known as IMACS (the International Association for Mathematics and Computing in Simulation), Ro Favreau, an SCi pioneer, spoke about SCi and the new journal SIMULATION. Three years later, in 1967 at the next AICA Congress in Lausanne, Switzerland, fellow academics, asked John McLeod how to go about setting up a council and thus began the process of the SCi Board of Directors approving charters for new international councils.

By 1975 UKSC was able to organize its first UK Simulation Conference on the shores of Lake Windermere in the English Lake District. The formation of UKSC proved to be the start of an extended period of international growth through which the society transformed itself from a largely North American network of local groups into an international professional society. In 1985, a European office of the Society was established in Ghent. Creation of the European office produced an increase in the international membership of SCS and led to the creation of two annual European conferences, the European Simulation Multiconference (ESM) held in June and the European Simulation Symposium (ESS) in October. UKSC eventually became an independent organization from SCS.

The McLeod Institute for Simulation Sciences (MISS)
One of the most enduring legacies of the society may turn out to be the formation of the McLeod Institute for Simulation Sciences (MISS) in honor of its founder, John McLeod. Ralph Huntsinger of California State University, Chico (SCS President from 1986-88) first proposed the establishment of the McLeod Institute in the 1970s. The Board of Directors approved the idea in 1976 and later established the first MISS center at California State University, Chico. The MISS centers were created to collaborate on research projects, share software and expertise, arrange exchange visits, and collaborate in developing academic programs in the field of Modeling and Simulation (M&S).

McLeod Modeling and Simulation Network (M&SNet)
Established in 2003 to address a more specific focus, M&SNet was initially a world-wide consortium of 14 independent organizations and an active network of researchers, academicians and practitioners devoted to support the continuous improvement of the discipline of Modeling & Simulation and its applications. Its continuing mission is to search for innovative ways to use M&S as well as innovative domains of application and to disseminate M&S principles as well as theoretical, technological, and ethical knowledge. M&SNet, under the direction of Agostino Bruzzone, continues its aim of creating an evolving framework for sharing experience and knowledge in which participants have the possibility of effective cooperation & knowledge exchange for successful collaborations through its international meetings.

Reinventing the Society
The late 1990s were a time of rapid growth in the recognition and use of modeling and simulation as an enabling technology in a wide range of applications.

In 1993 the SCS Board of Directors (BoD) approved a structural overhaul of the BoD and the Executive Committee, and changed the focus of the Society to be more responsive to members and industry as a whole. One of the early outputs of the effort was the SCS Mission Statement, characterizing the society as an “international multidisciplinary forum dedicated to research, development, and applications of simulation”, which guided future SCS operations and growth.
In the rapidly changing environment of the 1990s, constant review of the society's status and strategic directions proved necessary, and in 1998 incoming President Axel Lehmann established a Council of Advisors charged with addressing the challenges facing the society and making recommendations for change. The Council was made up of leading figures in the M&S community who were not Society insiders, chaired by a Past-President of SCS. The Council of Advisors started work in 1999 and presented its report to the Board of Directors in 2001. As a result of its recommendations the Society first changed its name and mission statement to reflect the current emphasis on both modeling and simulation. The Society became The Society for Modeling and Simulation International, but retained the SCS logo, the acronym of SCS and its legal name, Simulation Councils Inc. for continuity. All publications were redesigned and were outsourced to Sage Publications with the introduction of a new journal SIMULATION: The Transactions of the Society for Modeling and Simulation International.

SCS Today
The 2000s have been very busy with SCS desiring to further the trend from only conferences to publications and meetings. In 2003 SCS started The Journal of Defense Modeling and Simulation (JDMS): Applications, Methodology, Technology, a quarterly refereed archival journal devoted to advancing the practice, science, and art of modeling and simulation as it relates to the military and defense. The primary focus of JDMS is to document, in a rigorous manner, technical lessons derived from practical experience. The journal also publishes work related to the advancement of defense systems modeling and simulation technology, methodology, and theory. The journal covers all areas of the military / defense mission, maintaining a focus on the practical side of systems simulation versus purely theoretical applications.

Professional Certification & Body of Knowledge
In 2000, the SCS Council of Advisors recommended a professional certification for simulationists. Admiral Fred Lewis, Executive Director of the National Training Systems Association, also called for certification in his keynote address at SCS’s Summer Computer Simulation Conference in July 2000. Under Admiral Lewis' leadership, certification is now a reality. SCS members have contributed in key ways towards making this happen. Certification is granted to all members of the M&S community who hold sufficient credentials, which are based on education, work experience, and community standing, and who pass the certification exam.

Professional certification is just one aspect of SCS efforts to define and create a simulation profession. In 2023 a Body of Knowledge (BoK) was created by Tuncer Oren, Bernard P. Zeigler, and Andreas Tolk as Editors, with the help of the Simulation community. The BoK can be used in university curriculum and professional development programs.

SCS subsequently took steps to internationalize its activities by deciding to hold its flagship summer conference outside the US every year starting with Edinburgh in 2008. Since then, the conference has been held in Istanbul, Ottawa, The Hague, Genoa, Canada, and Berlin, as well as a variety of other international locations.

Each year SCS has held three major conferences a year: the Powerplant Simulation Conference, which brings together the fossil and nuclear simulation community, in the winter; the Spring Simulation Multi-Conference (SpringSim) event, which covers a wide variety of simulation interests, held typically in April or May; and the Summer Simulation Multi-Conference (SummerSim) event, which also covers a wide variety of simulation interests, held typically in June or July. Each conference was designed to appeal to the Simulation communities domestically and internationally. In 2021 SpringSim and SummerSim were merged into a new event named the Annual Modeling and Simulation Conference (ANNSIM).

Membership with SCS offers benefits as SCS partners with other groups in the simulation community to offered benefits such as discounted registrations to events such as Winter Simulation Conference (WSC), American Automatic Control Council Conference (AACC) and American Association for the Advancement of Science (AAAS) events. SCS Members enjoy free access to all of its journals through Sage Publications, to Simulation books printed in cooperation with Springer Nature, as well as discounts on all printed SCS proceedings through Curran Publications. We also now offer developing country memberships and offer virtual sessions during our annual conference events.

In the more than half a century since the Simulation Council was formed, the organization that we now know as the Society for Modeling and Simulation International (SCS) has evolved from a small local group of aerospace professionals into an international organization with affiliations and activities wherever modeling and simulation is practiced. SCS survives & thrives because there are still many devoted members who are determined to have it remain so. Members have always been & continue to be key to the health of the Society. SCS may have lost some ground in being at the forefront of Simulation as the field continues to spread through more & more disciplines, but it continues to work to bring simulationists together through offering ways to publish papers on simulation in its two journals with regard to its use/impact in a wide variety of fields as well as offer opportunities to connect in person with fellow simulation professionals at its annual simulation events. History Book.

In Memoriam: Meet the McLeods


(The article below was originally published in Instruments and Automation, Volume 28, No. 4, April 1955)

John H. McLeod, Jr., Head of the Functional Simulation Branch, Guidance Div., Naval Air Missile Test Center, Point Mugu, Calif., has been publishing the now well-known Simulation Council Newsletter since November 1952. This was shortly after he sparked the formation of the first Simulation Council. The primary purpose of the Newsletter is to report on the Council discussions.

The high value of the Newsletter stems from the fact that simulation technique opens a new frontier for industrial, as well as military and engineering, instrumentation. And the technique is most apparent from the discussions of those engaged in simulation. It is in recognition of this fact that Instruments and Automation will, beginning with this issue, publish monthly the Simulation Council Newsletter. This will make the Newsletter avail­ able not only to all present subscribers to the Newsletter but also to nil subscribers to Instruments and Automation. The Newsletter now reports the discussion of the Western, Midwestern, and Eastern Councils, plus those of the Industrial Analysis and Control Council; meetings of the Association for Computing Machinery, the IRE, PGEC, and others concerned with computers and simulation are also covered when possible.

The Newsletter and Bob Lowry, former Secretary of the Midwestern S. C., were instrumental in the forming of the Midwestern and Eastern Councils, which are now headed by Dr. Milton Warshawsky of WADC and Dr. Harold Skranstad of the National Bureau of Standards, respectively.

McLeod was born in Hattiesburg, Mississippi, February 27, 1911. He graduated from Tulane University in 1933, with a degree in mechanical and electrical engineering.

His experience includes the application of Automatic Control Instruments as Field Engineer with Taylor Instrument Companies, and their design as Research and Development Engineer with Leeds & Northrup Company. Since 1947 he has been concerned with the automatic stabilization and control of guided missiles, and the analysis and Synthesis of control systems by means of analog computer techniques at the USNAMTC, Point Mugu.

He has presented papers at two Cyclone Symposia, the Typhoon Symposium, the 1954 National Association of Computing Machinery Convention, the American Rocket Society's 1954 Fall Meeting, and the recent Louisiana State University High-Speed Computer Conference.

Your editors believe that you will enjoy Mr. McLeod’s literary style, as well as benefit from the great insight that his reports give to the new technique of simulation.

McLeod tells us “The most appropriate picture to use with any mention of me is that of Suzette and me, because it was Suzette who suggested the Newsletter and whose hard work made it possible.” Thus, we invite you to meet both John and Suzette.

Note that Mr. McLeod first worked in industrial instrumentation - and from there entered the "then-new" field of analog computation, where he discovered completely new and different techniques and procedures for instrumentation. In the brief time from 1952 to 1955 the new techniques were perfected and standardized, commercial equipment became available, basic circuits were developed for hysteresis and other non linearities, the great potentials of simulation for industry became apparent, and the new techniques became ready for the industrial field. The appearance of the Simulation Council Newsletter in Instruments and Automation thus marks the beginning of a new era, the introduction of simulation techniques into the industrial instrument field. Mr. McLeod has returned from whence he started; the tide of events has turned full-circle.