The specification of sample size is an important aspect of the planning of every experiment. When the investigator intends to use the techniques of analysis of variance in the study of treatments effects, ho should, in specifying sample size, take into consideration the power of the F tests which will be made. The charts presented in this paper make possible ~ simple and direct estimate of the ...

The effect of measurement errors on adaptive and non-adaptive control charts has been occasionally considered by researchers throughout the years. However, that effect on the variable sample size and sampling interval (VSSI) control charts has not so far been investigated. In this paper, we evaluate the effect of measurement errors on the VSSI control charts. After a model development, the effe...

Control charts are used to determine whether or not a manufacturing or business process is in a state of statistical control. Various schemes of the standard (Shewhart) X chart for autocorrelated data at sample sizes of 2 and 3 are developed and compared with the schemes of the same chart for IID data at various process shifts in the process mean. It is clear from the comparison that the in-con...

The influence of the estimation of parameters in Shewhart control charts is investigated. It is shown by simulation and asymptotics that (very) large sample sizes are needed to accurately determine control charts if estimators are plugged in. Correction terms are developed to get accurate control limits for common sample sizes in the in-control situation. Simulation and theory show that the new...

Traditionally, the statistical quality control techniques utilize either an attributes or variables product quality measure. Recently, some methods such as three-level control chart have been developed for monitoring multi attribute processes. Control chart usually has three design parameters: the sample size (n), the sampling interval (h) and the control limit coefficient (k).The design parame...

Control chart is the most well-known chart to monitor the number of nonconformities per inspection unit where each sample consists of constant size. Generally, the design of a control chart requires determination of sample size, sampling interval, and control limits width. Optimally selecting these parameters depends on several process parameters, which have been considered from statistical and...