Military systems analysis is an extension of operations-research techniques of World War II to problems of broader context and longer range—e.g., force composition and development as well as operations decisions. Greater complexity is inevitable as we attempt analyses to aid decisions affecting more distant time periods: growth in number of relevant variables, compounding of uncertainties; increased importance of enemy reactions; complications of time phasing, the need for a broader concept of criteria Techniques available to the systems analyst for dealing with these complexities are less than satisfactory. “Factoring” is inevitable. All routine or mechanistic approaches are deficient; e.g., expected value and minimax criteria. Design and criteria problems are of dominant importance. The systems analyst may have to be content with better rather than optimal solutions, or with devising and costing sensible methods of hedging; or merely with discovering critical sensitivities. He has an important role as inventor of systems. The difficulties of systems analysis are rooted in the nature of the military problems. Other methods—e.g, piecemeal analysis or intuition—do not escape them and have limitations of their own. Military systems analysis provides a framework for combining the knowledge of experts in many fields to reach solutions which transcend any individual expert's judgment. Operations Research, ISSN 0030-364X, was published as Journal of the Operations Research Society of America from 1952 to 1955 under ISSN 0096-3984.