The sampling strategy of economic design of x-bar control charts for non-normally distributed data under Weibull shock models

摘要

The constant sampling intervals were widely employed by the control chart's designers and users because of its administrative simplicity. Hu (1984) proposed a research outcome of economic design of an x-bar control chart under a Weibull distribution with fixed sampling intervals. Banerjee and Rahim (1988) present a cost model using variable sampling intervals as opposed to sampling intervals of fixed-length under a process-failure mechanism, which follows a Weibull model or some other model with an increased hazard rate. However, these measurements in the subgroup are assumed to be normally distribution when designing control charts. That assumption may not be tenable. This investigation develops the economic design of x-bar control charts for non-normal data under Weibull shock models with various sampling intervals. Finally, the example of Banerjee and Rahim (1988) is adopted to indicate the solution procedure, implement sensitivity analysis and compare the outcome of using various sampling approaches.