Introducing Impact Analysis for Architectural Decisions

Architectural quality constitutes a critical factor for contemporary software systems, especially because of their size and the needs for frequent, quick changes. For success-critical business systems, architectural decisions are of high risk for the market share and even for the existence of enterprises. These decisions are important for design processes as well as for refactoring. Because of the complexity of the decisions, e.g., uncertain, contradicting goals, unknown effects and risky conditions, decision-making is a difficult and risky task. Risks can be minimized if the decisions are made systematically. In an earlier paper, we introduced methods of decision theory to perform such decisions in a rational way. This paper introduces a method for evaluating alternatives of architectural decisions, for both architectural design and refactoring. This method adopts elements of the scenario-based evaluation method ALMA (Bengtsson et al., 2004). A practical example illustrates the application of the improved decision process