The CMMS concept, Conceptual Models of Mission Space, has been presented by the US DMSO as a way to facilitate the development, and enhance the reuse and interoperability of simulation models. CMMS is one of the major components for implementing the DoD´s M&S Master Plan. CMMS is the first abstraction of real-world military operations. That is, an implementation-independent description real world processes, entities, environmental factors, and associated relationships and interactions constituting a particular set of missions, operations or tasks. A feasibility study of CMMS has been performed at the Swedish Defence Research Agency (FOI) in 2001. Focus was placed on studying the concept of CMMS and identifying the central components in it. A follow-up study has been made during the autumn 2002 supplementing and updating the results from the previous study. This report presents the results from the studies mentioned above. Our studies have so far indicated that the CMMS concept would bring great advantages if adopted by the Swedish Armed Forces.