Experience with performing architecture tradeoff analysis

Software architectures, like complex designs in any field, embody tradeoffs made by the designers. However, these tradeoffs are not always made explicitly by the designers and they may not understand the impacts of their decisions. This paper describes the use of a scenario-based and model-based analysis technique for software architectures-called ATAM-that not only analyzes a software architecture with respect to multiple quality attributes, but explicitly considers the tradeoffs inherent in the design. This is a method aimed at illuminating risks in the architecture through the identification of attribute trends, rather than at precise characterizations of measurable quality attribute values. In this paper, the operationalization of ATAM is illustrated via a specific example in which we analyzed a U.S. Army system for battlefield management.