The author's experiences over a span of more than 50 years are characterised as a journey. Early interests in computer system performance modelling, information storage and retrieval, and computer networks become secondary to research topics in computer simulation. Organisations, events, and, most important, people define the paths, waysides, excursions, side roads, and major stops along the way. Editorial positions constitute an enduring thread throughout the journey. Capturing and preserving the history of the modelling and simulation discipline, frequently a topical sojourn, emerges as a dominant activity in the latter years. Two evocative questions, based on the prediction of a prominent computing pioneer, conclude the paper. [GRAPHICS] .

The development history of the Computer Simulation Archive is described from its inception in 1998 to the present. An overlap of visions among the creators produces an asset for the simulation community and the North Carolina State University Libraries. Collections donated over this period have produced impressive growth. Usage statistics show a steady increase in access, and the simulation endowment has nearly tripled over the past six years. The commitment of the North Carolina State University Libraries staff and the strong, consistent support of the simulation community are the key factors in this record of success.

The evolution of computer simulation software until the mid-1980's is subsumed by descriptions of the history of simulation programming languages. Since that time, the entire complexion of simulation model design, development, execution, and sustainment has undergone a radical transition. The transition to a large degree stems from technology advances in hardware and software coupled with the increasing expectations of simulation modelers and end users. This study, covering the evolution in its entirety, represents an initial perspective on the transition based on an examination and analysis of the Winter Simulation Conference Archive and a partial set of simulation software surveys published in OR/MS Today. The results characterize the modeling and simulation software evolution since the mid-1980's in terms of newcomers, endurers, fads, fades, trends, and trajectories. Prominent among the conclusions are that commercial firms are driving the major advances and the marketplace is quite volatile.

Innovation in Modeling and Simulation (M&S) refers to exploiting new ideas, exploiting new technology, and employing out-of-the-box thinking, which lead to the creation of new methodologies, techniques, concepts, frameworks, and software. This paper addresses the following questions: (a) what was the state of the art in M&S 50 years ago, what is it today, how much progress has been made? (b) how much innovation in M&S has been accomplished over the last half a century? (c) what were the obstacles to innovation in M&S? (d) what are some recommendations to promote innovation in M&S? (e) what message should be sent to the funding agencies to encourage innovation in M&S?

Hybrid Simulation comes in many shapes and forms. It has been argued by many researchers that Hybrid Simulation (HS) provides more and better insights into the real-life system as it allows modelers to assess its inherent problems from different dimensions. As a result HS is becoming an important field within the Modeling and Simulation arena. Yet we find that there is no clear and/or cohesive definition for it. Therefore, this panel paper aims to explore the concept of HS and its progression through the years. In doing so, we hope to lay out the underpinnings of a structured HS approach by providing historical narratives of the origins of hybrid models; the current challenges expressed by scholars; and future studies to ensure more focused development of a comprehensive methodology for HS.

Reflections and recollections spanning a professional lifetime disclose a number of the usual or expected influencing factors or aspects by which an individual's career might be characterized, perhaps even gauged.Persons, projects, organizations, events, and technology advances are familiar shapers of a professional record.However, a surprising factor in this chronology is the role of a classical problem: machine interference or machine repair.This persistent problem recurs at various junctures, sometimes quite subtly at other times rather starkly, throughout the past 50 years.Descriptions of the effects of the expected factors are intertwined with the machine interference problem in this recap of a career in computer simulation and software engineering.

The primary objective of the project titled “A Retrospective Oral History of Computer Simulation” is to document the emergence of computer simulation since World War II. We seek to capture the early history of the field through digital videos of interviews with the pioneers whose seminal contributions have had long-lasting impacts on simulation practice and theory. This project involves the following activities: (a) identifying those pioneers who are to participate in the project; (b) making the logistical arrangements necessary to produce high-quality digital-video recordings of structured interviews with those pioneers; and (c) carrying out the interviews, editing the recordings, and posting those recordings in a universally accessible permanent digital repository. The digital videos produced by this project will be made freely available on the Web site of the Simulation Archive hosted by the North Carolina State University Libraries. We discuss progress to date and future plans for the project.

This chapter discusses teaching as characterized in Buddhist texts and as undertaken by those who intend to convey those texts authoritatively. It examines the normative and historical elements of the Buddhist preacher—a figure constantly associated with the transmission of Buddhist teaching from generation to generation. In the first part, the chapter considers important portraits of this Buddhist preacher drawn in Buddhist sūtras and śāstras. These portraits explain the preacher's pedagogical competence in terms of four discriminations: dharma, things, expression, and eloquence. The latter part aims to present how idealized portraits of teachers painted in texts may have complied—and sometimes failed to comply—with the practices of those outside the texts who would shape and be shaped by them.

In response to a request from the WSC Foundation and the WSC 2010 Program Committee, we review and slightly revise our survey of the history of simulation up to 1982, with special emphasis on some of the critical advances in the field and some of the individuals who played leading roles in those advances. Documenting the history of simulation remains a work in progress on our part, and we encourage individuals and organizations in the simulation community to bring significant historical data to our attention.

We survey the history of simulation up to 1981, with special emphasis on some of the critical advances in the field and some of the individuals who played leading roles in those advances.

This paper presents the "position papers" contributed by the participants of a panel at the 2008 Winter Simulation Conference. As the paper pre-dates the actual panel, the purpose of the paper is to provide some background information about the views of the individual panelists prior to the actual panel. Each panelist was asked to submit a position paper addressing the general question of "What makes good Modeling and Simulation research?" This paper presents a summary of these position papers along with an introduction and conclusion aimed at identifying the common themes to setup the conference panel.

This paper presents the "position papers" contributed by the participants of a panel at the 2008 Winter Simulation Conference. As the paper pre-dates the actual panel, the purpose of the paper is to provide some background information about the views of the individual panelists prior to the actual panel. Each panelist was asked to submit a position paper addressing the general question of "What makes good Modeling and Simulation research?" This paper presents a summary of these position papers along with an introduction and conclusion aimed at identifying the common themes to setup the conference panel.

Reuse has been very difficult or in some cases impossible in the modeling and simulation (M&S) discipline. This paper focuses on how reuse can be accomplished by using a conceptual model (CM) in a community of interest (COI). We address the issue of reuse in a multifaceted manner covering many areas (types) of M&S such as discrete, continuous, Monte Carlo, system dynamics, gaming-based, and agent-based. M&S is commonly employed and reuse is critically needed by many COIs such as air traffic control, automobile manufacturing, ballistic missile defense, business process reengineering, emergency response management, military training, network-centric operations and warfare, supply chain management, telecommunications, and transportation. We present how a CM developed for a COI can assist in reuse for the design of any type of large-scale complex M&S application in that COI. A CM becomes an asset for a COI and offers significant economic benefits through its effective reuse.

Unique operational and environmental characteristics define pervasive services and computing; they, too, define an ideal atmosphere in which security risks flourish. Ever-present accessibility through the networked and wireless infrastructures, dependency on autonomous and often anonymous computing agents, and the ubiquitous nature of pervasive services make them both enticing and easy targets for ill-intentioned activities. To help mitigate that risk, we propose an adaptive, access-driven verification, validation and testing (VV&T) strategy that, through a Process/Object Model of Computation, (a) identifies those resources and software objects most susceptible to attack, (b) enumerates violable constraints and assumptions underlying those attacks, and (c) provides multi-level strategies incorporating resources, software objects, and constraints and assumptions to determine if, and to what extent, systems supporting pervasive computing are vulnerable to security exploits. The VV&T strategies are defined to accommodate various levels of access to the software development process and its artifacts.

This panel session will discuss various issues regarding simulation life-cycle models. Simulation life-cycles models have received little attention, and this panel session seeks to generate interest in this topic and stimulate new ideas for development, teaching, and use of these models.

The utility and benefits of a well-defined requirements engineering process are cited in many articles describing software engineering research and similar industry studies. In this paper we consider to what extent the M&S community employs software requirements engineering (SRE) in the model development process. We motivate the desirability of having an SRE component by first outlining current SRE models and their touted benefits. To help formulate a reasoned conclusion, we examined several recent M&S books and three M&S Life- cycle models for references to requirements in the M&S activities. Our findings, also outlined in this paper, indicate that the use of any formal SRE activities within M&S development and analysis is minimal, at best. Nonetheless, our investigation has also uncovered some recent changes that point to a rise in the awareness of the need for a more formal, well-defined approach to software requirements engineering in the M&S model development process. We note those changes and some additional opportunities for increased SRE use.

AbstractThis paper reflects one aspect of an overall research initiative to better understand and articulate the “cause and effect” relationship between design causes and operational effects. Here the specific focus is on “before the fact” system maintainability. Maintenance considerations for software intensive systems must be addressed early in design and must focus on the entire system life cycle. Use of commercial‐off‐the‐shelf (COTS) components in system architectures reinforces this need. COTS usage can be readily observed in modern commercial and defense systems. Such architectures are often characterized by an evolving physical baseline (technology refreshment) driven by obsolescence considerations. This paper proposes aspects of a framework to evaluate system architectures, with a particular focus on system maintainability and with the objective of positively influencing the long‐term cost of operational maintenance.

A GPSS model is developed for simulating air traffic flow at a major metropolitan airport. It simulates scheduled and non-scheduled flights; and incoxporates Official Airline Guide flight schedules, Department of Transportation delay statistics, and additional data obtained from all airlines operating out of Detroit Metropolitan Wayne County Airport. Simulation outputs include: capacity and delay statistics which can be tabulated by runway, gate, and air carrier. This model can be used to study the effect of weather conditions, scheduling patterns, and runway utilization modes on airport congestion and flight delays.

The development of a large scale communications system is complicated by the great scope of design considerations. The Command and Control Communications and Informatin Network Analysis Tool (C3INAT) simplifies this problem by use of a stratified model which separates Command and Control C2 and communication sub-models which may be developed independently. The C3INAT then integrates the two sub-models so that a communication system may be evaluated in light of its effect on Cz. C3INAT also provides efficient interfaces to existing data bases and the modular General Simulation System (GSS). Its output is compatible with most data base and statistical analysis packages.