Economic Control Chart Designs and the In-Control Time Distribution: A Sensitivity Study

Abstract

Economic control chart models typically assume that the time to the occurrence of an assignable cause follows an exponential distribution. This paper extends that assumption to the Weibull distribution in order to investigate in general the impact, on economic control chart parameters and hourly costs, of the distributional assumption. It is found that the economic design is quite insensitive to the assumed distribution. In addition, an alternative formulation of the Lorenzen-Vance type unified expected cost function is presented.

• Economic Control Charts
• Weibull Distribution
• Sensitivity Analysis

Additional information

Notes on contributors

Thomas P. McWilliams

Dr. McWilliams is an Assistant Professor with the Management Science Group, College of Business Administration. He also works with Los Alamos National Laboratory as a Visiting Collaborator. He is a Member of ASQC.