High Quality Content by WIKIPEDIA articles! IDEF0 is a function modeling methodology for describing manufacturing functions, which offers a functional modeling language for the analysis, development, reengineering, and integration of information systems; business processes; or software engineering analysis. IDEF0 is part of the IDEF family of modeling languages in the field of software engineering, and is built on the functional modeling language Structured Analysis and Design Technique. The IDEF0 Functional Modeling method is designed to model the decisions, actions, and activities of an organization or system.