The Chapter Nine of Operation Management
Quality Control and Improvement
Chapter outline
9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 Design 'Of quality control systems Process quality control Attribute control Variables control Using control charts Continuous improvement Six Sigma Lean and Six Sigma Quality control and improvement in industry Student Internet exercises Solved problems Discussion questions Problems Selected bibliography
9.10 Key points
I
In the last chapter, we reviewed the long history of quality management. In the early 1900s, inspection shifted from the workers to a formal quality control department. This created tension between the workers and the inspectors, which is still evident in some companies today. But those who use the modern ideas of quality control are able to avoid these tensions and create a positive environment for quality improvement. In 1924, Walter A. Shewhart of the Bell Telephone Labs developed a statisti cal quality control chart. Two others from the Bell Labs, H. F. Dodge and H. G. Romig, further developed the theory of statistical quality control in the 1930s. But little was done in industry until World War II in the early 1940s. The war created the demand for huge quantities of military goods from industry. The mil itary required that industry adopt the new methods of statistical quality control to help ensure that the goods they ordered would meet government standards. As a result, statistical methods for control of quality were widely adopted by
169
170
Part Three
Quality
industry during the early 1940s. In later years, however, these methods were abandoned, only to be rediscovered in the 1980s as a valid way to ensure qual ity products and services. The service industries have been reluctant to adopt the methods of statistical quality control. While some service companies have made impressive gains in use of these methods, many others have lagged behind. As a result, there is a tremendous opportunity to use the methods of statistical
Chapter outline
9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 Design 'Of quality control systems Process quality control Attribute control Variables control Using control charts Continuous improvement Six Sigma Lean and Six Sigma Quality control and improvement in industry Student Internet exercises Solved problems Discussion questions Problems Selected bibliography
9.10 Key points
I
In the last chapter, we reviewed the long history of quality management. In the early 1900s, inspection shifted from the workers to a formal quality control department. This created tension between the workers and the inspectors, which is still evident in some companies today. But those who use the modern ideas of quality control are able to avoid these tensions and create a positive environment for quality improvement. In 1924, Walter A. Shewhart of the Bell Telephone Labs developed a statisti cal quality control chart. Two others from the Bell Labs, H. F. Dodge and H. G. Romig, further developed the theory of statistical quality control in the 1930s. But little was done in industry until World War II in the early 1940s. The war created the demand for huge quantities of military goods from industry. The mil itary required that industry adopt the new methods of statistical quality control to help ensure that the goods they ordered would meet government standards. As a result, statistical methods for control of quality were widely adopted by
169
170
Part Three
Quality
industry during the early 1940s. In later years, however, these methods were abandoned, only to be rediscovered in the 1980s as a valid way to ensure qual ity products and services. The service industries have been reluctant to adopt the methods of statistical quality control. While some service companies have made impressive gains in use of these methods, many others have lagged behind. As a result, there is a tremendous opportunity to use the methods of statistical