mistake proofing

huangyhg

mistake proofing
    we are a commercial heat treating plant who is currently undergoing our qs9000 registration.  i am having trouble defining mistake proofing.  none of he manuals that we have give a specific definition, only that verification by an operator ( visual ) is not enough.  any information on mistake proofing would be appreciated.
thanks
generally speaking, mistake-proofing (also called poka-yoke, and spelled in a variety of ways) involves designing the parts, assemblies, and fixtures such that a defective part cannot be used or made.  some examples include:
- using locating holes and pins to orient a part in the correct position.
- designing a fixture so that an incorrect size part won't fit.
- designing tooling so that it cannot physically make a defective part.
the main focus should be (1) don't make a bad part, and (2) parts and assemblies should be "self-inspecting".
hope this helps!