In emergency management operators and commanders must rely on dynamic, distributed systems and organisations for safe and effective mission accomplishment. Commanders and operators often experience extreme risk exposure, and coping with environmental hazards, fear, exhaustion and compulsion is part of their profession. They routinely handle highly ambiguous decision situations, where critical demands are inflicted upon their cognitive abilities and response times. In the future they will make decisions in situations where operational and system characteristics are highly dynamic and nonlinear, i.e. small actions or decisions may have serious and irreversible consequences for the entire mission. Commanders and operators are required to manage true real-time system properties at all levels, individual operators, stand-alone technical systems, higher-order integrated sociotechnical systems and joint operations forces alike. Coping with these conditions in performance assessment, system development and operational testing is a challenge for practitioners, instructors and researchers. Using a monotheory approach such as classic decision theory and multiattribute utility theory is nearly impossible. New results, new measurement techniques and new methodological breakthroughs facilitate a more accurate and deeper understanding, generating new and updated models and paradigms. This in turn generates theoretical advances. Some good examples of successful polytheory approaches are found in the research areas of cognitive systems engineering, systems theory, and psychophysiology, and in the fields of dynamic, distributed decision making and naturalistic decision making. A successful attempt to integrate these areas into a coherent framework, Action Control Theory (ACT) is described. Copyright © 2002 Inderscience Enterprises Ltd.