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Appendix A Background on Systems Theory Over the past 50 years or so, researchers have built up a considerable literature on systems theory that includes both theoretical perspectives and case studies of specific applications. DOT should capitalize on this work in establishing its process for selecting and funding R&D projects in surface transportation security. Because the systems engineering literature may be unfamiliar to many readers, this appendix briefly summarizes some key points and provides a few references for further reading. This discussion is not meant to provide a complete survey of the literature. Kahneman, Slovic, and Tversky (1982) showed clearly that unaided decision making is fraught with numerous biases. A systematic methodology provides some protection against these biases. Much of the early work on systems engineering focused on techniques rather than methodology (see, for example, Morse and Kimball, 1950). In some ways, the successes of systems engineering and operations research during and immediately after World War II, primarily in military projects, impeded the development of a formal methodology (see Hall, 1989). However, by the late 1950s and 1960s a number of systems thinkers had begun to define overriding methodologies rather than focusing on specific techniques (e.g., Churchman et al., 1957; Hall, 1962; Ackoff et al., 1962; and Churchman, 1968). At the heart of these methodologies were five steps: problem definition, generation of alternatives, evaluation, decision, and implementation. These are the same five stages described in Chapter 3 in the recommended R&D strategy for surface transportation security. The steps are typically taken in sequence, but results may sometimes require going back to a previous step. Backwards motion
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does not necessarily mean failure. For example, problems that consist of several phases may require several passes through the sequence, so that each phase can incorporate feedback from earlier phases. The five-step methodology matches closely with the rational decision-making model studied by economists and political scientists, an approach that was discredited as a descriptive model for organizations and economics by March and Simon (1958) and for political decision making by Allison (1971). In systems engineering, however, the methodology is intended to be normative rather than descriptive. Moreover, the systems engineering context lacks the computational and organizational limitations that social scientists highlighted for practical economic and political situations. Recent work has focused on extending the basic approach. Many situations, especially large defense projects, require consideration of legal and contractual issues in addition to technological evaluation (Blanchard, 1998, and DOD, 1996). The nature of complexity and the search for general approaches to describing it have altered some features of the basic approach (Albin and Foley, 1998). Several researchers have developed and employed ''soft" methodologies for working with problems that have loose, ill-structured, or ill-defined specifications (Checkland and Scholes, 1990). The methodology described in the body of this report relies primarily on the basic methodology without these recent additions, but extensions could be accommodated easily. References Ackoff, R.L., S.K. Gupta, and J.S. Minas. 1962. Scientific Method: Optimizing Applied Research Questions. New York: John Wiley and Sons. Albin, P.S., and D.K. Foley, eds. 1998. Barriers and Bounds to Rationality: Essays on Economic Complexity and Dynamics in Interactive Systems. Princeton, N.J.: Princeton University Press. Allison, G.T. 1971. The Essence of Decision. Boston: Little Brown. Blanchard, B. 1998. Systems Engineering Management. 2nd ed. New York: John Wiley and Sons. Checkland, P., and J. Scholes. 1990. Soft Systems Methodology in Action. New York: John Wiley and Sons. Churchman, C.W. 1968. The Systems Approach. New York: Delacorte. Churchman, C.W., R.L. Ackoff, and E.L. Arnoff. 1957. Introduction to Operations Research. New York: John Wiley and Sons. DOD (U.S. Department of Defense). 1996. Mandatory Procedures for Major Defense Acquisition Programs (MDAPs) and Major Automated Information System (MAIS) Acquisition Programs. DODR 5000.2-R. Washington, D.C.: U.S. Department of Defense. Hall, A.D. 1962. A Methodology for Systems Engineering. New York: Van Nostrand. Hall, A.D. 1989. Metasystems Methodology: A New Synthesis and Unification. Oxford, U.K.: Pergamon. Kahneman, D., P. Slovic, and A. Tversky. 1982. Judgment Under Uncertainty: Heuristics and Biases. Cambridge, U.K.: Cambridge University Press. March, J., and P. Simon. 1958. Organizations. New York: John Wiley and Sons. Morse, P.M., and G.E. Kimball. 1950. Methods of Operations Research. New York: John Wiley and Sons.