AbstractThis paper provides an overview of operational analysis (OA) in the Ministry of Defence (MOD). It starts by describing what types of OA are undertaken, and goes on to discuss the management of this OA, in terms of the coordination of the many studies, the types of expertise sought in the personnel who undertake the work, and the balance between intramural and extramural activity. It then addresses more technical matters: the problems of coping with many potential scenarios, the problems associated with data uncertainty, the problems of selecting output measures, the problems of choosing between OA methods, the problems of validating studies of a postulated major war, and the problems associated with generating cost data.