The inventory of DoD models and simulations (M&S) has many overlaps in terms of functional capabilities. In an increasingly resource constrained environment, the ability to perform functional assessments and analysis of currently fielded and planned simulations takes on greater significance. Under the sponsorship of the U.S. Army Center for Army Analysis (CAA) and the Army Modeling and Simulation Office (AMSO), an analysis of U.S. Army "Brigade and Below" constructive simulations was conducted in two phases. This paper describes the framework used for this analysis which can serve as a model for other simulation portfolio assessments. Phase I consisted of a functional review of OneSAF (One Semi-Automated Forces) capabilities and user needs across various communities enabled by M&S. These communities included acquisition, analysis, experimentation, intelligence, test and evaluation, and training. Phase II expands upon the insights gained in the Phase I effort to examine a focused set of U.S. Army Brigade and Below constructive simulations. The role of U.S. Army Warfighting Functions, Service Task Lists and associated taxonomical elements are discussed in this paper, as well as the methodology used for data collection and analysis of data. Details are provided that show how simulation functionality was contrasted and compared. This methodology addresses the fact that, for complex multi-resolution applications, more than one level of functionality may be supported with a single constructive simulation.