Abstract

In the last 10 years, the emphasis on quality has permeated practically all areas of society. This has been especially true in the chemical process industry. Total quality management, statistical process control, statistical quality control, and just-in-time inventory are a few of the programs which have been instituted in the quality improvement process. Most programs and approaches can be applied to most industries. A few, however, notably statistical process control and quality control, are more applicable to the manufacturing industry. Although first developed in the 1920s by Shewhart, these statistical tools have found a new application as consumers demand more from the products that they purchase.

The use of control charting has been heavily emphasized in manufacturing. The technique graphically displays a process, identifies assignable cause variation, and allows control of a process. Control charting is readily conducive to continuous (commodity product) processes but, unfortunately, can present many difficulties when applied to a batch (specialty product) process. An effective quality control program, which incorporates the use of statistics for process understanding and decision making, can be achieved in a batch or specialty chemical product production facility. This article addresses the distinction between the application of quality methods in the batch process versus continuous process industries. For instance, control charting for a batch process has serious limitations because of the number and complexity of the products being produced. The utilization of basic statistical tools to identify potential problem areas in batch process facilities is presented. The authors present instructive examples that have been used to emphasize to managers the importance of applying the proper tools.