Using Counts to Monitor a Process Mean

Abstract

A procedure for controlling α process mean to a target midway between two specified values is presented. It is assumed that the process variable has a normal distribution with unknown mean and variance, and that the data consists solely of counts of the number of observations in a sample which are above, below, and between specified gauge values. Charts are given for conveniently accomplishing the test and for estimating the amount of adjustment needed. Finally, the choice of gauge limits is discussed and comparisons are made with variables procedures.

• Process Control
• Sign Test
• Narrow Limit Gauging
• PRE-Control

Additional information

Notes on contributors

Nicholas R. Farnum

Dr. Farnum is an Associate Professor of Management Science. He is a CQE and a Member of ASQC.

Laverne W. Stanton

Dr. Stanton is an Associate Professor of Management Science.