SPC's Effectiveness Prediction and Analysis

SPC’s Effectiveness Prediction and Analysis (1998)
P. Grabov, ALD Ltd., Israel

The article presents a simple measure for process state evaluation-ratio of the inherent variation to the total variation-and a procedure for its calculation. The ratio could be used as a guide for local adjustment required to eliminate assignable causes, or for an action on the system intended for global process improvement. The procedure is illustrated by numerous case studies applicable to different industries and processes.