New Attributes and Variables Control Charts under Repetitive Sampling

Abstract

New control charts under repetitive sampling are proposed, which can be used for variables and attributes quality characteristics. The proposed control charts have inner and outer control limits so that repetitive sampling may be needed if the plotted statistic falls between the two limits. Particularly, the new np and variable X-bar control charts under repetitive sampling are considered in detail. The in-control and out-of-control average run lengths are analyzed according to various process shifts. The performance of the proposed control charts is compared with the existing np and the X-bar control charts in terms of the average run lengths.

Economic design of an attribute control chart for monitoring mean life based on multiple deferred state sampling

“…Meanwhile, it is said to be out‐of‐control ARL, when it is calculated from out‐of‐control process and denoted by ARL 1 . Several authors have studied the performance of different control charts using the ARL (see, for example, the works of Aslam et al).…”

“…The MDS sampling plays a major role in reducing the required sample size since it makes the decision using the sample results of current and/or successive/previous lots. For more references on MDS sampling plans, one may refer to the works of Vaerst, Soundararajan and Vijayaraghavan, Balamurali et al, Balamurali and Jun, and Aslam et al Similarly, control charts designing based on MDS sampling are also available in the literature (see, for example, the works of Aslam et al).…”

An attribute control chart for multivariate Poisson distribution using multiple dependent state repetitive sampling

“…Sellers et al 10 suggested that when the number of defects on each unit is classified into more than two categories, it follows a multivariate Poisson distribution (MPD). More details of this type of control charts can be seen in the studies of Patel, Lowry and Montgomery, Lu, Skinner et al, and Aslam et al [11][12][13][14][15] Control charts are usually designed using single sampling as it is easy to apply in the industry. However, single sampling needs a larger sample size to make a decision in a control chart.…”

A new multivariate EWMA control chart via multiple testing

“…Stoumbos and Sullivan [10] studied the robustness of MEWMA charts to non-normality. However, detecting a small change in a process mean or variance as quickly as possible with tolerable false alarms is still a challenging problem in various areas [11][12][13].…”