An economic study of the [formula omitted] chart design

Abstract

Since the 1950s, various models have been proposed for a number of Shewhart-type charts including X and R charts employed jointly. Apart from such works, however, the design of a procedure to monitor and control process variability appears to have commanded very little attention. In 1989, Collani and Sheil first discussed the economic design of the s chart. However, they did not give a procedure to determine the optimal parameters of the s chart. This paper presents a procedure to economically determine the optimal parameters of the s chart. The results and the execution times of all numerical examples show that this procedure is quite accurate and efficient.