Time truncated control chart using log logistic distribution

Abstract

Control charts are considered as important tools when producer wants to produce goods or services of high–quality. These charts help producers to manufacture products based on specified limits by monitoring the quality beforehand.1 There are a number of control charts developed to monitor production process in different situations. One of the major characteristics of many control charts is that the production process should follow normal distribution. Ouyang et al.2 and Pearn and Wu3 they mentioned efficiency of process capability (PC) based on the production process which follows normally distributed processes. According to Aslam and Jun1 there are also other control charts which are developed based on non–normal distributions which are being used when the production process follows other distributions rather than normal. Rao4 developed a control chart for time truncated life tests using exponentiated half logistic distribution and Rao et al.5 constructed attribute control charts for the Dagum distribution under truncated life tests.