Quality Improvement Papers
Recent Issues in Statistical Process Control:
SAS Solutions Using Statistical Modeling Procedures
Robert Rodriguez, SUGI Proceedings, 1994.
Abstract
Although the Shewhart chart serves well as the fundamental tool for statistical process control (SPC) applications, its assumptions are challenged by many modern manufacturing environments. For example, when standard control limits are used in applications where the process is sampled frequently, autocorrelation in the measurements can result in too many out-of-control signals. Other situations considered in this paper include the presence of multiple components of variation, the issue of short run process control, and the effect of nonnormal process data. While some of these problems are subjects of ongoing research, statistical models that extend the basic Shewhart model can provide effective solutions. This paper demonstrates the use of SAS procedures for statistical modeling in conjunction with the SHEWHART procedure.
