This paper proposes a rigorous technique to evaluate the architectural design of an information system and illustrates this technique by applying it to the JSIMS architecture [1]. This technique represents an information system problem as a graph of necessary decisions and the information flows needed to support those decisions. It represents the architectural design as a graph of data interfaces, knowledge stores, decision makers and communications. Rules of information flow mapping the problem model onto the architectural model clearly show what decisions and information flows the design does and does not support. These design strengths and weaknesses emphasize where design improvements can reduce technical, cost and schedule risks. The JSIMS architecture's ability to address the problem of composing simulation exercises was evaluated. This evaluation indicates that the JSIMS architecture can support exercise composition but cannot provide the functionality needed to achieve the staffing reduction targets for JSIMS.