Function model
（重定向自Functional model）
![Example of a function model of the process of](/Images/godic/202501/14/IDEF_Diagram_Example5054.jpg")
![Example of functional decomposition in a systems analysis.](/Images/godic/202501/14/Fo2ufg823rhf832hfdorfg5054.JPG")
![Functional block diagram of the attitude control and maneuvering electronics system of the Gemini spacecraft. June 1962.](/Images/godic/202501/14/Functional_block_diagram_of_the_attitude_control_and_maneuvering_electronics_system5054.jpg")
![Functional Flow Block Diagram Format.[13]](/Images/godic/202501/14/Functional_Flow_Block_Diagram_Format5054.jpg")
A function model or functional model in systems engineering and software engineering is a structured representation of the functions (activities, actions, processes, operations) within the modeled system or subject area.
A function model, similar with the activity model or process model, is a graphical representation of an enterprise's function within a defined scope. The purposes of the function model are to describe the functions and processes, assist with discovery of information needs, help identify opportunities, and establish a basis for determining product and service costs.