this paper addresses the design of control charts for both variable ( x chart) andattribute (u and c charts) quality characteristics, when there is uncertainty about the processparameters or sample data. derived control charts are more flexible than the strict crisp case, dueto the ability of encompassing the effects of vagueness in form of the degree of expert’spresumption. we extend the use o...

in this paper, first the available single charting methods, which have been proposed to detect simultaneous shifts in a single process mean and variance, are reviewed. then, by designing proper simulation studies these methods are evaluated in terms of in-control and out-ofcontrol average run length criteria (arl). the results of these simulation experiments show that the ewma and ewms methods ...

The coefficient of variation is a very important process parameter in many processes. A few control charts have been considered so far for monitoring its multivariate counterpart, i.e., the (MCV). In addition, autocorrelation likely to occur processes with high sampling frequency. Hence, designing suitable and investigating effect on these necessary. However, no chart has developed that capable...

Small and medium-sized unmanaged grid-connected photovoltaic (PV) systems are difficult to manage owing the installation costs of monitoring systems. Consequently, they can be left unattended for a long time following break downs. Thus, in this study, we developed low-cost remote system small-sized PV The proposed is equipped with failure detection algorithm based on simulation an active that a...

Statistical process control (SPC) has been used to achieve and maintain control of various processes in industry (Stoumbos, Reynolds, Ryan, and Woodall 2000). The control chart is a primary SPC tool to monitor process variability and promote quality improvement by means of detecting process shifts requiring corrective actions. As a graphical monitor, control charts generally contain a centerlin...

The application of protective gel, which is a subprocess of the electronic assembly of the exhaust gas recircula‐ tion sensor, is a highly capable process with the fraction of nonconforming units as low as 200 ppm. Every unit is inspected immediately after gel application. The conven‐ tional Shewhart chart is of no use here, and the ap‐ proach based on the Bernoulli process is therefore conside...

Statistical process control, a recognized technique for improving quality and productivity, has been widely employed throughout various industries. The conventional Shewhart control charts are applicable only when the collected sample data are real-valued data. For the purpose of controlling uncertain information when interval-valued data inevitably appear in the manufacturing or service proces...

The Decision On Belief (DOB) control chart is a univariate that was initially introduced as solution to the problem of less than optimal limits from shewhart attribute diagram, especially C. new scheme based on DOB calculation step , can change data which not normally distributed into normal distribution, then diagnose quality process errors. . defines belief or an assumption in observation vec...