IDEF6 or Integrated Definition for Design Rationale Capture is a method to facilitate the acquisition, representation, and manipulation of the design rationale used in the development of enterprise systems. Rationale is the reason, justification, underlying motivation, or excuse that moved the designer to select a particular strategy or design feature. More simply, rationale is interpreted as the answer to the question, “Why is this design being done in this manner?” Most design methods focus on the what the design is (i.e., on the final product, rather than why the design is the way it is).
IDEF6 will be a method that possesses the conceptual resources and linguistic capabilities needed (i) to represent the nature and structure of the information that constitutes design rationale within a given system, and (ii) to associate that rationale with design specifications, models, and documentation for the system. The scope of IDEF6 applicability covers all phases of the information system development process, from initial conceptualization through both preliminary and detailed design activities. To the extent that detailed design decisions for software systems are relegated to the coding phase, the IDEF6 technique should be usable during the software construction process as well.