**Function definition diagrams depicting functional relationships and their inputs, outputs, mechanisms, and controls.** The first IDEF (**I**ntegrated **DEF**inition) 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. # ICOM The [[Positional Semantics]] of arrows entering function blocks: ![[Image 1.png|https://lh3.googleusercontent.com/pw/ACtC-3da5jn0E5gc7MD8IXi9lcXuo_og2sj4X_OPfu4dSWQ8lPuwH4fB5HSK4xih-LhMayNw_PpX324O2H_m2O_NUwPLGz6kKwzXQD4I_zHgsh9ODsRBBJQVf17-YIERKVDmvuZuTrg8g2LmmTmgi-7m3KW55w=w900]] ## 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. ## Calls Not used often. If a function invokes another function external to the model (I think, a function specified in another [[IDEF]] model). I personally don't see much value in using "Calls", as they ruin the simple semantics and don't add a ton of [[Communicative Value]]. **** # More ## Sources - The IDEF0 Spec - https://nvlpubs.nist.gov/nistpubs/Legacy/FIPS/fipspub183.pdf - [IDEF0 Functional Modeling](https://aarongilly.com/gillespedia/idef0/) ## Related - [[IDEF]] - [[IDEF0 Rules]] - [[IDEF0 Tools]] - [[Diagram Types (index)]]