When there is a change in a process, the MaxMin exponentially weighted moving average (EWMA) control chart shows which parameters have increased or decreased. The MaxMin EWMA may also be viewed as smoothed tolerance limits. Tolerance limits are limits that include a specific proportion of the...

Purpose – The purpose of this paper is to present the application of a procedure for the quality control of stainless steel tubes produced for automotive exhaust systems from a leading company in the steel sector, based on the Delphi method in accordance with the ISO/TS 16949:2009 and the ISO...

States that, under certain circumstances, a single • control chart with tightened control limits may be more effective for detecting process shifts than the combination of • and s control charts, while the type I error can be kept at the same level. A computer program is developed to decide...

Studies the necessity of controlling the variation of the skewness of the process distribution in order to reduce the product scrap. Proposes a γ control chart for detecting the skewness shift, also implements a simulation procedure to decide the control limits of the γ chart.

Studies the economic design of x ‐ control charts in a situation in which the duration time that the process remains in the in‐control state follows a general distribution which has an increasing hazard rate. In this situation, the active and persistent action for quality control is to...