"Capability" refers to the ability of a process reliably to produce conforming parts. Capability calculations sometimes obscure the economic loss that arises from a stable process being centred off target.
Here is a little dialogue-box - driven Excel™ workbook that allows you to see the impact of process centre and process variation on capability indices and total economic loss characterised by a Taguchi loss-function.
For more details see: D J Wheeler, Beyond Capability Confusion, SPC Press, 1999, Ch. 9
This page last updated 29th June 2001
copyright ©2000-2001 by A N Cutler