ABSTRACT
Just like in the case of other engineering disciplines, over the years many analytical methods for use in quality work have been developed. These methods are statistically and nonstatistically based [1, 2]. The main objective of all these methods is to improve the quality of products and services. The history of the quality analysis methods may be traced back to a memorandum written by Walter Shewhart of Bell Laboratories on May 16, 1924 [1, 3]. In this memorandum Walter Shewhart presented the idea of a control chart.
