Process capability indices (PCIs) can be used as an effective tool for measuring product quality and process performance. In classic quality control there are some limitations which prevent a deep and flexible analysis because of the crisp definition of PCA‟s parameters. Fuzzy set theory can be used to add more flexibility to process capability analyses. In this study, the fuzzy X ba and MRx ba...

In today’s competitive business environment, it is becoming more crucial than ever to assess precisely process losses due to non-compliance to customer specifications. To assess these losses, industry is widely using process capability indices for performance evaluation of their processes. Determination of the performance capability of a stable process using the standard process capability indi...

The process capability indices are widely used by quality professionals as an estimate of process capability. The lower confidence limits of PCIs are difficult to be estimated by parametric methods for some non-normal distributed processes. The non-parametric but computer intensive Bootstrap techniques are utilized for these cases. The Percentile-t Bootstrap (PTB) method is used to estimate the...

The capability analysis of production processes where there are more than one correlated quality variables is a complicated task. The problem becomes even more difficult when these variables exhibit non-normal characteristics. In this paper, a new methodology is proposed to estimate process capability indices (PCIs) of multivariate non-normal processes. In the proposed methodology, the skewness...

T he question of assessing the capability of a process to produce according to some specifications connected with a measurable characteristic (X) of the items produced through it is of great importance in statistical process control. These specifications consist of the lower specification limit (L), which is the minimum acceptable process value; the upper specification limit (U), which is the m...

In today’s competitive business and industrial environment, it is becoming more crucial than ever to assess precisely process losses due to non-compliance to customer specifications. To assess these losses, industry is extensively using Process Capability Indices (PCIs) for performance evaluation of their processes. Determination of the performance capability of a stable process using the stand...

Optimization methods have been widely applied in statistics. Among them, capability measuring techniques are widely applied in industries. Process Capability Indices (PCIs) have been proposed for measuring process production capability. This paper concentrates, the lower and upper confidence limits for the PCIs are obtained from generalized pivotal quantity of random model and also, use this co...

Process capability indices such as Cp, Cpk, Cpu and Cpl are common metrics to evaluate and predict the performance of a process. Although higher process capability indices indicate higher process “quality”, but a high quality process does not necessarily guarantee the fewer rates of rejects. Therefore, a process capability index based on rate of rejects or real losses is more reliable and prope...