IDEF refers to a modeling language family that encompasses various uses, ranging from functional modeling to data, simulation, object-oriented analysis/design, and information gathering. The IDEF0 Functional Modeling method represents an organization's or system's decisions, actions, and activities. It was derived from Douglas T. Ross and SofTech, Inc.'s established graphic modeling language Structured Analysis and Design Technique (SADT). IDEF0 defines a graphical modeling language (syntax and semantics) and a description of a full methodology for generating models in their original form. The SADT developers were tasked by the US Air Force to "create a function model approach for studying and expressing a system's functional perspective." IDEF0 should aid in the organization of system analysis and the promotion of good communication.