Using rationale to support pattern-based architectural design

Architectural design rationale describes the decisions made, alternatives considered, and reasons for and against each alternative considered when defining a software architecture. At least some of these reasons should reference the non-functional requirements (NFRs) for the system. The SEURAT_Architecture system uses a pre-defined pattern library and the NFRs for a software system to guide the selection of architectural patterns. Each pattern recommended by the system serves as an alternative to the architectural decision made and comes with rationale for why this pattern is considered useful. This system serves several purposes---to guide the architect through the decision-making process, to ensure that NFRs are considered when making these critical early decisions, and to capture the rationale for the architecture as a byproduct of the tool-supported selection process.