Fred Spiring 
Determining and Assessing Process Capability for Engineers and Manufacturing [PDF ebook] 

Process capability continues to receive a great deal of attention from practitioners and researchers alike. Since Sullivan introduced the concept to North America, the focus on process capability is due in part to the changing philosophy in Quality Assurance. Slogans such as "doing things right the first time" and "building a quality product" are terrific motivators, however if a process is not capable of meeting requirements, resources will be wasted. For example, if a mechanical process is not capable, the operators, regardless of their dedication and effort, will be unable to produce a quality product. Similarly if the operators are not capable of meeting the demands of the machinery, a quality product will not result. Processes that are not capable, regardless of their incapacity, waste resources. The goal of the book is to illustrate use of the most common process capability indices with the sincere hope that it will foster the safe use and development of PCIs among practitioners and researchers.