Definition
Computer-aided process planning (CAPP) is the use of software to assist or automate process planning: determining which operations, machines and tooling are needed to manufacture a part from its CAD model and requirements. CAPP systems are typically divided into variant planning, which adapts an existing plan for a similar part, and generative planning, which attempts to derive a new plan automatically from geometry and requirements.
Why CAPP mostly assists rather than replaces a process planner
A fully generative CAPP system that reliably handles arbitrary parts and real factory constraints remains an open research problem after decades of work; most production CAPP tools assist a human process planner rather than replace one. See process planning.
Where CAPP fits in
Not on the drawing; CAPP is software used during process planning, taking the drawing, 3D model and part requirements as input to help produce a routing.
Common mistakes
Assuming a CAPP system can fully automate process planning for any part; even advanced systems typically need human review, especially for unusual geometry or factory-specific constraints.
A fully generative CAPP system that reliably handles arbitrary parts and real factory constraints remains an open research problem after decades of work; most production CAPP tools assist a human process planner rather than replace one. See process planning.
See how Blake reviews a partFrequently asked questions
Is CAPP the same as CAM?
No, CAPP decides how to manufacture a part (operations, sequence, machines); CAM generates the actual toolpaths and NC code for a chosen operation.
What's the difference between variant and generative CAPP?
Variant CAPP adapts an existing process plan for a similar part; generative CAPP attempts to derive a new plan automatically from geometry and requirements.
Can CAPP replace a work preparer?
Not fully with today's technology; most CAPP systems assist a human, handling routine cases while flagging or deferring harder ones.