Function definition diagrams depicting functional relationships and their inputs, outputs, mechanisms, and controls.

The first IDEF (Integrated DEFinition) method deals with representing interrelated functions within an enterprise. The method results in a set of diagrams wherein boxes representing functions are connected graphically using lines on their four sides. Then sides each are accurate with a type of relationship a thing has with the function.

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Inputs

These are the things that are modified by the function to become the outputs.

Controls

These are what tell the function how to produce the correct output.

Outputs

These are what the function exists to do.

Mechanisms

These are those things which the function needs to operate, but aren’t modified by it.


Sources