
Panel on Modeling and Simulation
Committee on Technology for Future Naval Forces
Naval Studies Board
Commission on Physical Sciences,
Mathematics, and Applications
National Research Council
NATIONAL ACADEMY PRESS
Washington, D.C. 1997
NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.
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PANEL ON MODELING AND SIMULATION
GEORGE F. CARRIER, Harvard University, Chair
PAUL K. DAVIS, RAND and the RAND Graduate School, Vice Chair
DONALD K. BLUMENTHAL, Gualala, California
RICHARD BRONOWITZ, Center for Naval Analyses
JOHN C. DOYLE, California Institute of Technology
DONALD P. GAVER, Naval Postgraduate School
DON E. HIHN, Charleston, South Carolina
RICHARD J. IVANETICH, Institute for Defense Analyses
JOHN P. LEHOCZKY, Carnegie Mellon University
DAVID L. McDOWELL, Georgia Institute of Technology
DUNCAN C. MILLER, Massachusetts Institute of Technology
DAVID R. OLIVER, Northrop Grumman Corporation
GABRIEL ROBINS, University of Virginia
BERNARD P. ZEIGLER, University of Arizona
Invited Participant
BEN P. WISE, Science Applications International Corporation
Navy Liaison Representatives
CDR THOMAS COSGROVE, USN, Office of the Chief of Naval Operations, N858D
CAPT JAY KISTLER, USN, Office of the Chief of Naval Operations, N6M
Consultants
LEE M. HUNT
SIDNEY G. REED, JR.
JAMES G. WILSON
Staff
RONALD D. TAYLOR, Director, Naval Studies Board
PETER W. ROONEY, Program Officer
SUSAN G. CAMPBELL, Administrative Assistant
MARY G. GORDON, Information Officer
CHRISTOPHER A. HANNA, Project Assistant
COMMITTEE ON TECHNOLOGY FOR FUTURE NAVAL FORCES
DAVID R. HEEBNER, Science Applications International Corporation (retired), Study Director
ALBERT J. BACIOCCO, JR., The Baciocco Group, Inc.
ALAN BERMAN, Applied Research Laboratory, Pennsylvania State University
NORMAN E. BETAQUE, Logistics Management Institute
GERALD A. CANN, Raytheon Company
GEORGE F. CARRIER, Harvard University
SEYMOUR J. DEITCHMAN, Institute for Defense Analyses (retired)
ALEXANDER FLAX, Potomac, Maryland
WILLIAM J. MORAN, Redwood City, California
ROBERT J. MURRAY, Center for Naval Analyses
ROBERT B. OAKLEY, National Defense University
JOSEPH B. REAGAN, Saratoga, California
VINCENT VITTO, Lincoln Laboratory, Massachusetts Institute of Technology
Navy Liaison Representatives
RADM JOHN W. CRAINE, JR., USN, Office of the Chief of Naval Operations, N81 (as of July 4, 1996)
VADM THOMAS B. FARGO, USN, Office of the Chief of Naval Operations, N81 (through July 3, 1996)
RADM RICHARD A. RIDDELL, USN, Office of the Chief of Naval Operations, N91
CDR DOUGLASS BIESEL, USN, Office of the Chief of Naval Operations, N812C1
PAUL G. BLATCH, Office of the Chief of Naval Operations, N911E
Marine Corps Liaison Representative
LtGen PAUL K. VAN RIPER, USMC, Marine Corps Combat Development Command
Consultants
LEE M. HUNT
SIDNEY G. REED, JR.
JAMES G. WILSON
Staff
RONALD D. TAYLOR, Director, Naval Studies Board
PETER W. ROONEY, Program Officer
SUSAN G. CAMPBELL, Administrative Assistant
MARY G. GORDON, Information Officer
CHRISTOPHER A. HANNA, Project Assistant
NAVAL STUDIES BOARD
DAVID R. HEEBNER, Science Applications International Corporation (retired), Chair
GEORGE M. WHITESIDES, Harvard University, Vice Chair
ALBERT J. BACIOCCO, JR., The Baciocco Group, Inc.
ALAN BERMAN, Center for Naval Analyses
NORMAN E. BETAQUE, Logistics Management Institute
NORVAL L. BROOME, Mitre Corporation
GERALD A. CANN, Raytheon Company
SEYMOUR J. DEITCHMAN, Institute for Defense Analyses (retired), Special Advisor
ANTHONY J. DeMARIA, DeMaria ElectroOptics Systems, Inc.
JOHN F. EGAN, Lockheed Martin Corporation
ROBERT HUMMEL, Courant Institute of Mathematical Sciences, New York University
DAVID W. McCALL, Far Hills, New Jersey
ROBERT J. MURRAY, Center for Naval Analyses
ROBERT B. OAKLEY, National Defense University
WILLIAM J. PHILLIPS, Northstar Associates, Inc.
MARA G. PRENTISS, Jefferson Laboratory, Harvard University
HERBERT RABIN, University of Maryland
JULIE JCH RYAN, Booz, Allen and Hamilton
HARRISON SHULL, Monterey, California
KEITH A. SMITH, Vienna, Virginia
ROBERT C. SPINDEL, Applied Physics Laboratory, University of Washington
DAVID L. STANFORD, Science Applications International Corporation
H. GREGORY TORNATORE, Applied Physics Laboratory, Johns Hopkins University
J. PACE VanDEVENDER, Prosperity Institute
VINCENT VITTO, Lincoln Laboratory, Massachusetts Institute of Technology
BRUCE WALD, Arlington Education Consultants
Navy Liaison Representatives
RADM JOHN W. CRAINE, JR., USN, Office of the Chief of Naval Operations, N81 (as of July 4, 1996)
VADM THOMAS B. FARGO, USN, Office of the Chief of Naval Operations, N81 (through July 3, 1996)
RADM RICHARD A. RIDDELL, USN, Office of the Chief of Naval Operations, N91
RONALD N. KOSTOFF, Office of Naval Research
Marine Corps Liaison Representative
LtGen PAUL K. VAN RIPER, USMC, Marine Corps Combat Development Command
RONALD D. TAYLOR, Director
PETER W. ROONEY, Program Officer
SUSAN G. CAMPBELL, Administrative Assistant
MARY G. GORDON, Information Officer
CHRISTOPHER A. HANNA, Project Assistant
COMMISSION ON PHYSICAL SCIENCES, MATHEMATICS,
AND APPLICATIONS
ROBERT J. HERMANN, United Technologies Corporation, Co-Chair
W. CARL LINEBERGER, University of Colorado, Co-Chair
PETER M. BANKS, Environmental Research Institute of Michigan
LAWRENCE D. BROWN, University of Pennsylvania
RONALD G. DOUGLAS, Texas A&M University
JOHN E. ESTES, University of California at Santa Barbara
L. LOUIS HEGEDUS, Elf Atochem North America, Inc.
JOHN E. HOPCROFT, Cornell University
RHONDA J. HUGHES, Bryn Mawr College
SHIRLEY A. JACKSON, U.S. Nuclear Regulatory Commission
KENNETH H. KELLER, University of Minnesota
KENNETH I. KELLERMANN, National Radio Astronomy Observatory
MARGARET G. KIVELSON, University of California at Los Angeles
DANIEL KLEPPNER, Massachusetts Institute of Technology
JOHN KREICK, Sanders, a Lockheed Martin Company
MARSHA I. LESTER, University of Pennsylvania
THOMAS A. PRINCE, California Institute of Technology
NICHOLAS P. SAMIOS, Brookhaven National Laboratory
L.E. SCRIVEN, University of Minnesota
SHMUEL WINOGRAD, IBM T.J. Watson Research Center
CHARLES A. ZRAKET, Mitre Corporation (retired)
NORMAN METZGER, Executive Director
Preface
This report is part of the nine-volume series entitled Technology for the United States Navy and Marine Corps, 2000-2035: Becoming a 21st-Century Force. The series is the product of an 18-month study requested by the Chief of Naval Operations, who, in a memorandum on November 28, 1995, asked the National Research Council to initiate through its Naval Studies Board a thorough examination of the impact of advancing technology on the form and capability of the naval forces to the year 2035. To carry out this study, eight technical panels were organized under the committee on Technology for Future Naval Forces to examine all of the specific technical areas called out in the terms of reference.
The study's terms of reference (Appendix A) asked for an identification of "present and emerging technologies that relate to the full breadth of Navy and Marine Corps mission capabilities," with specific attention to "(1) information warfare, electronic warfare, and the use of surveillance assets; (2) mine warfare and submarine warfare; (3) Navy and Marine Corps weaponry in the context of effectiveness on target; [and] (4) issues in caring for and maximizing effectiveness of Navy and Marine Corps human resources." The terms of reference went on to identify 10 technical areas for special attention. One involved modeling and simulation (M&S): "The naval service is increasingly dependent upon modeling and simulation. The study should review the overall architecture of models and simulation in the DoD (DoN, JCS, and OSD), the ability of the models to represent real world situations, and their merits as tools upon which to make technical and force composition decisions."
It was against this background that the Panel on Modeling and Simulation was constituted and asked to develop the present report. Upon reviewing the terms of reference and defining a feasible scope of work, the panel noted that recent documents (some of them produced after the terms of reference were created) already provide a reasonable architecture-level survey of the Defense Department's M&S, as well as a vision statement. In particular, the Office of the Secretary of Defense's (OSD's) Defense Modeling and Simulation Office (DMSO) has developed a substantial Master Plan for M&S, the purpose of which is to establish a common technical framework for DOD's M&S.1 Given this body of existing material, the panel focused its efforts on key issues that have previously received little or insufficient attention. The objectives the panel set for itself, then, were (1) to clarify why the Department of the Navy leadership should care and be concerned about the substantive content and comprehensibility of M&S; (2)to assess what the Navy Department (and DOD) may need to do to benefit fully from the opportunities presented by M&S technology; (3)to clarify what M&S can and cannot be expected to accomplish in aiding decisions on technical, force-composition, and operations planning issues; and (4)to present priorities for M&S-related research.
The panel made no attempt to conduct a full survey of M&S relevant to the Department of the Navy. Much of the report deals with large-scale joint models such as those used in campaign planning, the evaluation of systems and new doctrinal concepts, or joint traininge.g., M&S such as the Joint Warfare System (JWARS) and the Joint Simulation System (JSIMS) systems now under development. The report has less to say about engineering- or engagement-level models, although it discusses the important role of simulation-based acquisition. Finally, this report is not a "forecast," nor does it lay out "roadmaps" for what should be done decade by decade for the next 40 years. Instead, the panel has chosen to focus on a chronic problem that took many years to develop and will take many years to deal with effectivelythe lack of a good military-science research foundation on which to base the modeling and simulation that it so much depends onand on priorities for remedying that problem over the years ahead.
Panel membership included experts in the research for and development and application of modeling and simulation, in both defense and nondefense domains. It also included experts in force planning; operations planning; applied mathematics, including probability and statistics; modeling and simulation theory; physics, including statistical mechanics; control theory; computer science; electrical engineering; operations research; gaming; and strategic planning.
The panel met eight times to receive briefings from Service and industry representatives, visit facilities, deliberate, and draft its report. It also participated in the three plenary meetings for the overall study. The first plenary meeting, in March 1996, established organization and a common starting point for the entire study. It included presentations by the Chief of Naval Operations and other high-level officials of the Navy Department, the other Services, the Defense Department, and industry. The subsequent plenaries were for drafting, comparison and integration across panels, the working out of cross-cutting issues, and synthesis (reflected primarily in Volume 1: Overview). The result follows. The report (which consists of a summary, the main report, and a set of appendixes) discusses modeling and simulation as a foundation technology for many developments that will be central to the Department of the Navy and Department of Defense over the next 3 to 4 decades.
The panel report is, of course, a product of the whole. However, the
Vice Chair, Paul Davis, organized and led report preparation. He and Richard
Ivanetich also compiled the panel's work and briefed it to study leadership along the way.
1See Defense Modeling and Simulation Office. 1995a. Department of Defense Modeling and Simulation (M&S) Master Plan, Office of the Under Secretary of Defense for Acquisition and Technology, Washington, D.C., October; Kaminski, Paul G., Under Secretary of Defense for Acquisition and Technology. 1996. "DMSO 'Modeling and Simulation,'" Keynote address at DOD Fifth Annual Industry Briefing, Alexandria, Va., May 22; and other materialsboth formal and informalavailable from the DMSO or the DMSO's World Wide Web site at http://www.dmso.mil.
Acknowledgments
The Panel on Modeling and Simulation is indebted to many people who provided briefings, scientific papers, or discussion time. It gives special thanks to Darryl Morgeson and Chris Barrett of Los Alamos National Laboratory, Jeff Grossman of the Naval Research and Development Laboratory (NRaD), Les Parrish of SPAWAR, Bill Stevens and Jeff Steinman of Metron, Inc., Henson Graves of Lockheed Martin, Tom Skillman of Boeing, Timothy Horrigan of Horrigan Analytics, CDR Dennis McBride, USN, of the Office of Naval Research, and Wayne Hughes of the Naval Postgraduate School. CAPT Jay Kistler, USN, was the panel's contact with the Navy, the study's sponsor. Both he and CDR McBride provided useful briefings and contacts.
The panel also acknowledges RAND's courtesy in supplying several of
the figures used to illustrate concepts discussed in the report.
Contents
1 INTRODUCTION
2 TECHNOLOGICAL PROSPECTS FOR DOD'S M&S
3 POTENTIAL FAILURES AND DISASTERS FOR DOD'S M&S
4 DEALING WITH AND IMPROVING DOD'S M&S
5 FOCUSING WARFARE RESEARCH AND IMPROVING M&S
6 CREATING AND IMPROVING INTELLECTUAL AND TECHNOLOGICAL INFRASTRUCTURE FOR M&S KEY TECHNICAL PROBLEMS REQUIRING INVESTMENT
7 CHALLENGES IN ASSIMILATING AND EXPLOITING M&S TECHNOLOGY
BIBLIOGRAPHY
APPENDIXES
A TERMS OF REFERENCE
B VIRTUAL ENGINEERING: TOWARD A THEORY FOR
MODELING AND SIMULATION OF COMPLEX SYSTEMS
John Doyle, California Institute of Technology
C SIMULATION-BASED ACQUISITION
Richard Ivanetich, Institute for Defense Analyses
D EXPLORATORY ANALYSIS
Paul K. Davis, RAND and the RAND Graduate School
E MULTI-RESOLUTION MODELING AND INTEGRATED FAMILIES OF MODELS
Paul K. Davis, RAND and the RAND Graduate School
Bernard Zeigler, University of Arizona
F MODEL REPOSITORIES AND ASSEMBLY AND INTEGRATION OF MODELS
Bernard Zeigler, University of Arizona
Paul K. Davis, RAND and the RAND Graduate School
G COMPONENTS OF A THEORY OF MODELING AND SIMULATION
Bernard Zeigler, University of Arizona
H AREAS OF RESEARCH IN MODELING AND SIMULATION
Bernard Zeigler, University of Arizona
I COMBAT MODELING ISSUES
Paul K. Davis, RAND and the RAND Graduate School
Donald Blumenthal, Gualala, California
Donald Gaver, Naval Postgraduate School
J PROBABILISTIC DEPENDENCIES IN COMBAT MODELS
Paul K. Davis, RAND and the RAND Graduate School
K M&S-RELATED EDUCATION
Donald Gaver, Naval Postgraduate School
L ACRONYMS AND ABBREVIATIONS
OVERVIEW: CONCLUSIONS AND RECOMMENDATIONS
The Department of the Navy must take a new look at modeling and simulation (M&S):
Indeed, independent of Navy and Marine actions, M&S will be deeply embedded within joint command-and-control systems. Without enhanced efforts, the Navy and Marine Corps will not understand the strengths or limits of such models and simulations, nor be proficient with them.
M&S will also become a core feature of system development and acquisition, as is the case already in leading-edge civilian industry. Because of its centrality, M&S should be seen as an enterprise technology in itselfpart of the revolution in business affairs that is now a key element of the Department of Defense's (DOD's) overall strategy.
While the future of M&S should be exceedingly bright, the Department
of the Navy will not be able to exploit its potential unless it attends to serious
and chronic shortfallsthe most important of which relate not to software, but to
the quality and content of the underlying models. Dramatic advances are being
made in DOD's M&S, but these advances are associated mainly with computer
and software technologies. By contrast, too little attention has been focused on
the content of the models themselves, or on the research base needed to create
that content. Failure to address this shortfall will inevitably lead to less effective
but more expensive combat forces andquite possiblyserious operational failures.
The escalating complexity of planned systems and operations creates
profound integration challenges requiring superb M&S for successand for the
avoidance of downright failures.

All of this suggests that the Department of the Navy needs to make an attitude shift regarding M&S, which has never previously merited a high priority for leadership attention. Today, what is needed is a strategic commitment to exploiting M&S (Figure ES.1). This, of course, would lead to a strategy, policy, and investment actions. In this report the Panel on Modeling and Simulation identifies priorities for such matters. One priority involves the two principal joint simulation programs for training and analysis, the Joint Simulation System (JSIMS) and the Joint Warfare System (JWARS), respectively. Since first-generation versions will be quite imperfect and the systems may last 10 to 20 years, the panel recommends that the Department of the Navy take an active role to ensure that JSIMS and JWARS are produced as evolving systems that incorporate future research results. This is not simply a management issue, but rather something very challenging technically, since the architecture of the simulations must allow this evolution. Also, links must be created between the research and M&S worlds, links that do not now exist. And the research itself must be expanded substantially.
The research needed falls into two categories, warfare-area research and fundamental research. The former involves understanding the processes that take place in combat (e.g., those of littoral operations or long-range precision strike). This is military science, not programming, and commercial industry will not lead the way. The fundamental research needed involves theory and methodology that will make it possible to design and construct sound and reusable models and simulations that will also be comprehensible, flexible, and testable in specific contexts. Achieving these features will require major advances. It follows that the panel recommends that the Department of the Navy (working with other Services and DOD as appropriate) establish a robust but focused program in research, with both warfare-area research and research on fundamental theory and methods.
Unfortunately, research alone is not sufficient, and its fruits are often not harvested because researchers, M&S developers, warfighters, and other leadership figures are often disconnected. Accordingly, the panel recommends that the Department of the Navy establish processes that ensure early scientific review of models emerging from research, a competitive atmosphere in which "the market" of model users is both encouraged and assisted in constantly evolving their M&S to represent the best available knowledge (i.e., in assimilating improvements), and a general emphasis on quality, including the ability to represent uncertainty. Accomplishing this will require a multiyear commitment of senior leadership, because the baseline culture is very different from the one needed. Elements of a changed approach would include enhanced officer education and continual "beta testing" of models and simulations by organizations such as the war colleges and commands, testing that extends deeply into content, not merely software performance. However, such "operators" will need substantial assistance from the scientific community.
In addition to addressing the quality and content of models and
simulation, the Department of the Navy needs to make investments that cut across
usual organizational stovepipes and budget accounts. This relates to the promise
of simulation-based acquisition. Accordingly, the panel recommends that the
Department of the Navy treat simulation-based acquisition (SBA) as a key
enabling technology with extraordinary long-term leverage and that it organize and
invest consistently with that enterprise-technology
view.
RICH OPPORTUNITIES FOR MODELING AND SIMULATION
Modeling and simulation (M&S) offers the promise of greatly enhancing future naval force capabilities and achieving major cost savings. To cite a few examples:
Simulation-based acquisition (SBA). Representations of proposed system designs can be constructed and tested in simulated environments. These virtual prototypes can be used to refine system requirements and relate tradeoff and engineering decisions to these requirements. Subsequently, computer-based representations can be maintained as development and production occur, and as modifications are introduced throughout the life cycle. The results can be more affordable systems that are better attuned to an operator's needs, easier to assimilate, and easier to modify. The remarkable success of the Boeing 777's development merely tapped the surface of what will eventually be possible.
Decision support. M&S can assist commanders in their planning for combat and other military operations. Key uses include developing and assessing proposed courses of action, mission planning and rehearsal, and dynamic situation assessment and adaptation in the course of battle. M&S-based decision support also has an important role in peacetime activities such as concept evaluation and resource allocation.
Models and simulations are being used for all of these functions today.
Indeed, the breadth of M&S is enormous, as suggested by Figure ES.2. The
best-known recent successes have been in training, but there is rapidly growing
documentation on valuable applications throughout Figure ES.2's cubeas
judged not only by those advocating M&S, but also by senior commanders.
Documented examples of recent high-leverage payoffs from M&S are given in
Chapter 2, but the future is more relevant in this study. It is especially significant
for the future that M&S will be thoroughly embedded in command-and-control
systems. There have already been numerous exercises in which differences
between the real and the simulated have been blurred or made invisible to some
participants. This will be increasingly the case as U.S. forces adopt the
concepts sketched in the Joint Chiefs of Staff's Joint Vision 2010 (Shalikashvili, 1996).
THE POTENTIAL FOR FAILURES AND DISASTERS
Cautions Amidst Enthusiasm
Despite this bullish introduction and the fact that M&S will surely "take
off" in the commercial sector, the potential of M&S for the Department of the
Navy and DOD may not be realized in the foreseeable future. Some of the DOD's
most important and expensive M&S efforts may fail orperhaps worseend up
saddling the DOD components with mediocre, inflexible, and sometimes
misleading tools that impede innovation and improvement of content. There is also
the potential for disasters due to overdependence on M&S for images and
predictions that appear more valid than they actually are (the "Spielberg" effect). This
could cost lives and undercut military operations.
One basic problem is that DOD's investments have been concentrated more
on content-neutral computer and software technologies rather than on the content
of the models.1 On the technology side, much has happened, for example,
object-oriented programming, high-performance computing, computer-aided design,
and establishment of the communications protocols and infrastructure for
everything from collaborative, distributed, multidisciplinary, simulation-based
engineering design to large-scale distributed war games. The dramatic progress in
technology will assuredly continue because of commercial developments and DOD
efforts such as those of its Defense Modeling and Simulation Office (DMSO).
An Undernourished Knowledge Base
In contrast, there has been curiously little investment in the knowledge base determining the substantive content and quality of much M&Sparticularly higher-level M&S needed for mission- and campaign-level work. It is an open secret, and a point of distress to many in the community, that too much of the substantive content of such M&S has its origin in anecdote, the infamous "BOGSAT" (bunch of guys sitting around a table), or stereotypical versions of today's doctrinally correct behavior. There is a need for focused research on the phenomena of combat and other military activities, both historical and prospective. This is the realm of military science.
Another shortfall in knowledge relates to theories and methods for
conceiving, designing, and building models (as distinct from software). Symptoms of
the problem are evident if one observes that DOD's M&S often consists of
nothing more than the computer code itself: there is no separable documented "model"
to be reviewed and improved, nor any way to readily understand the
assumptions generating the simulation's behavior. This can hardly be a comfortable basis
for decision support.
Complex Systems
The inherent complexity of the systems and force operations that DOD is attempting to simulate introduces new difficulties. Too many forecasts are extrapolating unreasonably from the Boeing 777 experience, and from M&S successes in weapon-system and small-unit training, to imagined M&S systems of extraordinary complexity. Recent failures such as the automated Denver airport baggage system and the Federal Aviation Administration advanced air-traffic-control system suggest the difficulties associated with reliably modeling and engineering complex systems. The military operations envisioned for future forces in the information era involve exceedingly complex systems.
Complexity is a multifaceted concept, but to appreciate some of what is involved here, the panel notes that planners, commanders, and engineers are most familiar and comfortable with systems (and models) that are primarily static, linear, and deterministic. However, automated and integrated military systems (the systems-of-systems approach) involve systems and models that are dynamic, nonlinear, and heterogeneous interconnections of mixed subsystems, with a much more sophisticated treatment of uncertainty, including uncertainties about the opponent's intentions and actions.
The panel's principal observation here is that dealing with such complex
systems effectively is a decades-long task. In the meantime, there is need for
humility, multiple approaches and competition, patience, and hedges. And even
long-run success will require profound changes in the way M&S is conceived and
designed, as well as an across-the-board attention to its content and
validityin a sense that suitably recognizes uncertainties. The panel describes what is needed below.
Assimilation of M&S Technology
Finally, there are the problems of assimilation and exploitation. M&S is an enabling technology, but its value is cross-cutting, and it has no natural single home. Nor should it, sincein a partial defense of stovepipingthe majority of work must be dictated by the needs of individual applications. However, whenever such a cross-cutting technology is introduced or its use expanded, there are organizational and managerial challenges. The key to success is often having a strategy embraced by the organization's leadership.
Against this background diagnosis, the panel has observations and
suggestions in each of a number of subjects. In essence, the recommendation is for
a concerted and long-overdue effort to improve the research base for the
Department of the Navy's and DOD's models, and to ensure that the results of
research are in fact incorporated. The panel's recommendations include priorities
and suggestions for a strategy, not simply general funding of research.
RECOMMENDATIONS ON JOINT MODELS
Concerns
One useful focus for the Department of the Navy's thinking about M&S is the set of joint systems now in development (most prominently JSIMS and JWARS). Taken together, these worthy programs (including the Service components) have a price tag approaching $1 billion. It is DOD's intention that JSIMS and JWARS will become the core for all future joint work on training and analysis, respectively. Although this is unlikely (a wider range of models will probably prove necessary), it may indeed be that JSIMS and JWARS will dominate the joint M&S scene for the next 20 years. Thus, it is important to the Department of the Navy that naval forces be adequately represented. Otherwise, valuable training opportunities will be compromised and the Navy and Marines will suffer in the competitions about doctrinal changes, future missions, and force-structure tradeoffs. More generally, the quality of joint work will suffer.
Unfortunately, it is likely that first-generation versions of JSIMS and JWARS will not be satisfactoryeven with heroic efforts and even though the products will have many excellent features. There will be major shortcomings with respect to both content and performance. Consequently, the panel recommends that the Navy insist that DOD and the program offices adopt open-architecture attitudes that will promote rather than discourage substitution of improved modules as ideas arise from the research and operations communities, and that they build explicit and well-exercised mechanisms to ensure that such substitutions occur.
This recommendation may seem uncontroversial, and it calls for no more than what some of the programs (notably JSIMS) are projecting on viewgraphs, but the history of DOD modeling has often been to produce relatively monolithic and inflexible programs. Further, there has been great DOD emphasis in recent years on avoiding alleged redundancies, collecting "authoritative representations," and exercising configuration control. The panel observes widespread frustration among analysts and other substantive users of models, who see DOD's M&S efforts as driven by civilian and military managers who think models are commodities to be standardized, who sometimes seem to value standardization more highly than quality (harsh words, but too important to be omitted), and who have given near-exclusive emphasis to software technology issues. They and the panel believe that M&S should instead be seen as organic, evolving, and flexible systems with no permanent shape (but with standardized infrastructure, including many component pieces).
In fact, the visionary technical infrastructure being promoted by OSD's Defense Modeling and Simulation Office (DMSO) (and software technologists) will permit the open system approach and will permit competition among alternative models (e.g., alternative representations of ballistic-missile defense, mine warfare, or command, control, communications, computing, intelligence, surveillance, and reconnaissance (C4ISR)). Thus, while it would be easy for JWARS, JSIMS, and other systems to end up as rigid monoliths, with the right architecture and organizational structure DOD can have its cake and eat it: it can have "standard configurations" while still making it easy for users to substitute model components as new ideas and methods emerge. An important but more subtle aspect of this infrastructure is connecting model evolution to the R&D and operational communities concerned with both current and futuristic doctrine; and, significantly, nurturing a competition of ideas and models. In that way the evolution will be more like survival of the soundest than like continuation of what has previously been approved.
The panel underlines the problem of incorporating research results
when they exist because, at present, the communities that do research and the
programming of models often do not communicate well and there is little pressure
to assure that the "best" models are reflected in M&S. Indeed, there is
much pressure to avoid changes.
Technical Attributes Needed in Joint Models
Against this background of concerns, the panel recommends that the Navy advocate an approach to joint-model development that has a long-haul view and an associated emphasis on flexibility. The groundwork should be in current model-building efforts for the following, which will be important in selected applications in the years ahead:
Explicit decision models representing the reasoning and behavior of commanders and different levels, and reflecting in natural ways courses of action, plans, and the adaptations that commanders make in the course of operations.
Diverse representations of uncertainty, including use of probability distributions (and, sometimes, alternatives such as fuzzy-set concepts), even in aggregate-level models.
Systematic treatment of important correlations (e.g., the "configural effects" of mine warfare and air defense).
Explanation capabilities linking simulated behavior to situations, parameter values, rules and algorithms, and underlying conceptual models.
Mixed modes of play that are interactive, selectively interruptible (e.g., for only higher-level commander decisions), and automated. (The panel regards the option for human play as critical for analytic applications as well as training, and the option of closed play, e.g., of the opponent, as critical for training.)
Testing of new doctrinal concepts requiring new entities, attributes, and processes.
Different types of models. The systems should accommodate model types as diverse as general state-space and simple Lanchester equations, entity-level "physics-based" models, and agent-based models with emergent behaviors. They should employ such varied tools for such uses as statistical analysis, generation of response surfaces, symbolic manipulators, inference engines, and search methods (e.g., genetic algorithms). The models must be able to deal not just with old-style head-on-head attrition warfare, but also with maneuver warfare on a nonlinear battlefield in the information era, and with operations in urban sprawl. They must reflect different command-and-control concepts.
Tailored assembly. The systems should facilitate tailored creation of models, including relatively simple M&S for specific applications. That is, one should conceive of JSIMS and JWARS as tool kits with rapid-assembly and modification mechanisms. Excessive complexity obfuscates and paralyzes.
In some respects, the last item is the most important. Given the breakthroughs in software technology over the last two decades, it is feasible (though not easy)and essentialfor major M&S efforts to be designed for frequent adaptation, specialization, and module-by-module improvement. One should think of assembling the right model, not taking it from the shelf whole. Further, it should be possible to discard or abstract complexities irrelevant to the problem at hand. Doing so runs directly counter to the common inclination to seek high resolution for everything, but tailored simplifications are crucial in applicationsespecially when they involve "exploratory analysis" over diverse situations and assumptions rather than point calculations. The type of analysis is crucial when uncertainties are largeas they often are. In any case, the need for simplicity is generally much better understood by those who have conducted studies or exercises, or designed decision-support systems, than by those who develop software.
The panel notes, however, that there are limits to what can be
accomplished by assembly or composition. The Department of the Navy and DOD should
be skeptical about the notion that a single system (e.g., JWARS or JSIMS)
will prove useful to a wide range of communities. It is one thing to assemble
and tailor components for one study rather than another, or for one exercise
rather than another. It is a very different matter to have the same system and library
of components support a broad range of different functions (testing, exercises,
force planning, etc.). Viewgraphs postulating such versatility do not constitute
an existence proof.
RECOMMENDATIONS FOR RESEARCH
Research in Key Warfare Areas
As noted above, there has been relatively little recent investment in understanding the phenomenology of military operations at the mission and operational levels. Much of the basis for related M&S is still programmer hypothesis and qualitative opinions expressed by subject matter experts. This has not always been so. During and after World War II, operations research worked from a rich empirical base, but now the United States is entering a period of nonlinear, parallel, information-era warfare for which the intuition of scientists, operations researchers, and warriors is insufficient and unreliable. Further, it will be relying on complex systems working as designed in multifaceted joint campaigns. Success may be much less tolerant of errors in concept and execution than in days past. Indeed, some of the doctrinal concepts under discussion will involve very high risks.
Given, then, that improvement of the research base is essential, how might
it be accomplished? Rather than merely urging general support for research,
the panel recommends a managerially focused approach with priorities and
mechanisms for assuring relevance and assimilation.
Accordingly, the panel recommends that the Navy and Marine Corps select a few high-priority warfare
areas and create research programs to support them. These programs should be
organized so as to ensure close ties to operational and doctrinal-development
communities, and to relevant training and exercise efforts that could be mined as a
source of empirical knowledge (e.g., as suggested in Figure ES.3, which would
exploit emerging capabilities for distributed interactive simulation). This is a
nontrivial and potentially controversial suggestion, since the long-standing tradition
has been to avoidand even prohibitextensive data collection for use
beyond those being trained. The costs of such efforts would be small in comparison
with those for buying and operating forces, or even procuring large models.
Although the Department of the Navy (and DOD) need to make up for past failures
to invest adequately in research, this is a domain in which a total of $20 million
to $30 million per year can accomplish a great deal.

FIGURE ES.3 Using exercises as a source of empirical data for M&S. SOURCE: Reprinted, by permission, from Davis (1995b). Copyright 1995 by IEEE.
As a first list of warfare areas for focused research, the panel recommends the following, which have some overlaps:
Joint task force operations with dispersed forces;
Long-range precision strike against forces employing countermeasures;
Theater-missile defense, including counterforce and speed-of-light weapon options, against very large ballistic-missile and cruise-missile threats; and
Short-notice, early-entry operations with opposition.
Each of the above warfare areas has major knowledge gaps that could be narrowed by empirical and theoretical research closely tied to the "warrior communities."
This report describes key attributes of research programs for such warfare areas. An overarching theme is the need to take a holistic approach rather than one based exclusively on either top-down or bottom-up ideas. A second theme is that the research should be seen as focused military science, not model building per se. This will determine the type and range of people involved, and also the depth of the work.
Two examples may be useful here. The first is the challenge of developing command-control concepts for highly dispersed Marine Corps forces operating in small units far from their ship-based support and dependent on a constellation of joint systems. The Marine Corps is studying alternative concepts in the Hunter/Warrior experiments. Such experiments need to be accompanied by systematic research and modeling of different types, perhaps including new types of modeling useful in breaking old mind-sets. It is plausible, for example, that cellular-automata models could help illuminate behaviors of dispersed forces with varying command-control concepts ranging from centralized top-down control to decentralized control based on mission orders. To its great credit, the Marine Corps is exploring such possibilities, opting to accept some "hype and smoke" in the realm of controversial complex-system research in exchange for new perspectives and tools useful in doctrinal innovation. While the panel does not believe such simplified models will prove adequate in the long run, they can be very helpful in developing new hypotheses.
A Navy example involves mine and countermine warfare. From prior
research based on sophisticated probabilistic modeling accounting for
numerous "configural effects" (i.e., effects of temporal and spatial correlations), it is
known that effective strategies for mine-laying or penetrating minefields are
often counterintuitive. By exercising such models and simulation-based alternatives
in an exploratory manner (as distinct from answering specific questions), it should
be possible to develop decision aids of great value in training, acquisition, and
operations. Such aids should not, however, focus only on "best estimate"
single-number predictions; they should instead provide commanders with information about
odds of success, as a function of information. If the aids are to be useful, they must
be informed by an intimate understanding of operational commanders' needs.
Recommendations on Fundamental Research
While many research activities are best driven by applications, other critical areas of M&S research require more fundamental research that might be sponsored by the Office of Naval Research (ONR), other Service analogues, the Defense Advanced Research Projects Agency (DARPA), and the Director of Defense Research and Engineering (DDR&E). In what follows the panel suggests particular subjects for fundamental research, divided into theory, advanced methodologies, and infrastructure (including tools).
Modeling Theory
The panel recommends that research on the following be given priority:
Agent-based modeling and generative analysis. Some of the most interesting new forms of modeling involve so-called "agent-based systems" in which low-level entities with relatively simple attributes and behaviors can collectively produce (or "generate") complex and realistic "emergent" system behaviors. This is potentially a powerful approach to understanding complex adaptive systems generallyin fields as diverse as ecology, economics, and military command-control. A fundamental step in developing particular models and simulations is deciding which attributes and interactions to represent, and in what detail. This choice should be the one that most adequately describes the phenomena one is trying to observe, but that choice is often not known until the subsystems are connected and the simulation is run. Thus, methods should be developed to allow one to iterate on the choice of the initial representations of subsystem models, based on results of their use in interconnected systems.
Semantic consistency. Phenomenological representations in different simulations need to interact with one another in distributed simulations. Such interaction is meaningful only if the representations are "semantically consistent," that is, if there is a shared understanding of what concepts and data "mean." This requires commonality of context and definition (or well-understood translations). The Navy should track related research, adding to it for special purposes. It should also support DMSO efforts to develop common models of the mission space (CMMS), which will assist in establishing semantic consistency in particular contexts and in developing integrated families of models.
Advanced Methodologies
The general task of developing and using models and simulations, and the particular activity of forming phenomenological representations, would be aided by methodological advances. Particular topics are as follows:
Exploratory analysis under uncertainty. Running a simulation for one set of fixed conditions is generally not satisfactory since there are often large uncertainties throughout the system. Even normal sensitivity analysis on a one-variable-at-a-time basis does not suffice because of interaction effects. An important research area, then, is developing ways to use modern computer power to explore the space of simulation outcomes and to search for interesting regimes (e.g., regimes representing high or low risks for an operation or for especially profitable, or unacceptable, performance of a weapon). This research has implications for the design of models (some of it closely related to multi-resolution modeling), search engines, and visualization methods. It has even more profound implications for analysis and decision making because it encourages decision makers to ask not about best-estimate outcomes, which are often no more likely than very different ones, but rather about how outcomes of a strategy would be likely to vary as a function of the many assumptions in "scenario space." This can help by focusing attention on the need to avoid "dangerous regimes" in the course of operations, by focusing attention on the search for crucial information, and by emphasizing the need for both hedging and adaptability. This approach, of course, is quite different from the search for mythical optimality.
Infrastructure, Tools, and Supporting Technology
With regard to infrastructure, the following research areas are of particular significance:
Object repositories and interface standards to enhance reusability and composability. Object-oriented technology admits the possibility of assembling major parts of simulations to meet the demands of a particular application from sets of stored objects representing entities and processes. Realization of this capability requires being able to manage large numbers of objects and to ensure consistency despite involvement of multiple developers. Such a capability could reduce costs in simulation development and allow flexibility in simulation application. A key of OSD's strategy in this domain is embodied in the high-level architecture (HLA), which establishes standards for M&S that may be used in federations employing distributed simulation. Despite controversy and anxiety about program costs, the HLA is a needed step in the direction of increased modularity and interoperability. It will have many long-term benefits. The Navy should support and exploit the HLA initiativerecommending modifications as needed.
Explanation/traceability capability. This capability applies to all phases of the management process. For example, it would help document the source code with multimedia techniques so that one could understand the phenomena being represented, and it would help explain the results of a simulation by displaying the logic trail that led to the results. Realization of this capability would figure centrally in achieving the verification, validation, and accreditation (VV&A) of simulations, both in the formal sense and to the satisfaction of individual users. This capability is important for field commanders, managers, and engineers.
For example, commanders using M&S to assess courses of action may need to know the following: On what assumptions do the simulation outcomes depend critically; should those assumptions be modified and the simulations rerun; what if the component commanders are given contingent orders? The implications of having both comprehensible models and effective explanation/traceability capability are so significant for VV&A that the Navy should undertake more general efforts. The Navy should use commercial products where appropriate and should foster commercial development where necessary, since the capabilities required will have more general value (e.g., to computer-aided design). Such commercial coupling is necessary because development of these capabilities will be expensive.
Other tools. Many other tools are badly needed. These include tools for (1) automated scenario generation and experimental design and (2) postprocessing and data analysis.
Research Is Not Enough: Planning to Incorporate Its Fruits
There is one further challenge associated with research: assuring that its products are recognized and used appropriately. This is challenging because the research, M&S-building, and user communities are reasonably distinct. Those building M&S often are only minimally acquainted with cutting-edge research in either the phenomenology of warfare operations or modeling methodology. Further, their sponsoring organizations are often more interested in the stability of M&S (and the related gargantuan databases) than in improvements of "theory," the rewards of which may be less than immediately tangible. This state of affairs probably continues because so little higher-level M&S is bounced against empirical realities. The panel has several suggestions here:
Providing scientific review of such models to advise the Navy about the quality of the models in relation to scientific knowledge and best practices in the community, and
Redefining the JWARS and JSIMS programs to have a continuing component responsible for reviewing, sponsoring, and incorporating research results. The function should be one of nourishing military science, not merely administration or auditing. Major changes are needed if there is to be a resurgence of in-depth study of military phenomena and the kind of open scientific discussion and debate that will lead to top-quality M&S.
RECOMMENDATIONS ON ASSIMILATING
AND EXPLOITING M&S
The Need for Strategic Commitment
Finally, there are the organizational problems of assimilation and exploitation. As noted above, M&S is an enabling technology. However, whenever such a cross-cutting technology is introduced, there are organizational and managerial challenges. It is commonplace for the organization to measure the value of investments against the wrong yardsticks (e.g., saving money in narrow domains, as distinct from changing the very way the organization does business and improving effectiveness for mainstream missions). It is also common for investments to go awry because (1) the new technology is procured and used as an add-on without sufficient buy-in and influence by the organization's core responsibility and workers, (2) too much is done by committee without leaders and champions who understand the core business, or (3) the educational groundwork has not been laid. Despite much ongoing success, all of these M&S-related problems are visible in DOD's components, including the Navy and the Marine Corps.
Based on the history of technology assimilation and the specifics of the current situation with respect to M&S, the panel recommends that the Department of the Navy make a strategic commitment to the success of exploiting M&S. Such a commitment would have consequences for organizational structure and responsibility (although the panel makes no recommendations on such matters), investment mechanisms (e.g., assuring that investment funds are available without forcing program managers always to make tradeoffs within their own domains), and the establishment of clear policies and strategies that would make manifest the leadership's demand for constant improvements in "validity" (as understood in the context of sometimes-extreme uncertainties) and usefulness to decision makers. As discussed above, the panel believes that the appropriate strategy would place considerable emphasis on warfare areas and cross-cutting modeling challenges, rather than still more emphasis on computer and software technology. To put this more bluntly, if funding tradeoffs are needed within M&S budgets, then the panel recommends giving higher priority to research improving model content rather than programming or reprogramming of current models.
In addition to investing in research to improve the quality and content
of models, the Department of the Navy must organize, plan, and invest
strategically if it is to enjoy the potentially great benefits of simulation-based acquisition.
In doing so, it should take a long view because, as in other aspects of M&S, there
are substantial obstacles. Success will be evolutionary over a period of decades.
Education for Next-generation Officers
One element of a strategy should be increased education in M&S for
next-generation officers. The effective exploitation of M&S depends on the
experience, knowledge, and wisdom of its practitioners, hence upon their education.
The panel recommends increased Navy investment in such education at all levels:
for those who acquire and design M&S tools, and also for those who rely on
them to guide acquisition, training, and
operations. Some of the education should be in the form of enhanced master's and Ph.D.-level programs. Other aspects
should include short courses tailored for officers needing refresher courses,
technology updates, and preparation for next assignments involving M&S management.
1There are some partial counterexamples, of course: e.g., "knowledge acquisition" for the "semiautomated forces" (SAFOR) used in the Joint Countermine Operational Simulation (JCOS) and the Army's tactical training system, new modeling of C4ISR effects in JWARS, development of object models, and research on configural effects. Even in these cases, however, the work has often been more like "computer modeling" than establishing an empirical and theoretical research base.