Control charts are extensively used in manufacturing contexts to monitor production processes. This article illustrates economical design of a variable sample size and control limit Hotelling’s T2 control chart based on a novel cost model when occurrence times of the assignable causes are exponentially distributed. The proposed nonlinear cost model is an extension of Duncan’s (J Am Stat ...

Control charts are the most important tools of statistical process control used to discriminate between assignable and common causes of variation and to improve the quality of a process. To design a control chart, three parameters including sample size, sampling interval, and control limits should be determined. The objectives are hourly expected cost, in-control average run length, power of th...

ABSTRACT. Goal: The main objective of this research paper is to propose a chart, named  Modified Control Chart, where the process variance () allowed be larger than in-control value until maximum (), as long remains capable, in sense that it produces specified (tolerated) small fraction non-conforming items. Design / Methodology Approach: methodology was quantitative approach with statistical...