Control Charts for Attributes

Statistical Process Control for Managers is an eight-chapter book published by Business Expert Press in 2014 and written by Victor E. Sower, professor emeritus of operations management at Sam Houston State University. The book provides a conceptual approach to using statistical process control (SPC) to inform and improve decision-making around business processes and quality improvement. The author reviews the basic methods of SPC and provides practical guidance for using specific tools. He incorporates real-world examples throughout the book and ends each chapter with a summary of key points, as well as questions for managers to ask when applying the concepts to their own organizations. Chapter 6, Control Charts for Attributes (13 pages), looks at methods for measuring go/no-go or count information such as the number of defective units overall, or number of customer complaints received. The author compares and contrasts four methods to use depending on what is being counted, defective products or defects in products. First, he looks at the utility of the proportion defective control chart (p-chart) and number-defective control chart (np-chart), reviewing the pros and cons for each. Second, he offers a similar analysis of the count chart (c-chart) and count chart per unit, (u-chart). There is a chart at the end of the chapter to guide how to select the appropriate method for the process.

• Operations strategy
• Statistical analysis
• Quality control
• Quality management
• Process improvement