A First Course in Quality Engineering

Integrating Statistical and Management Methods of Quality, Third Edition

K.S. Krishnamoorthi, Arunkumar Pennathur, V. Ram Krishnamoorthi

• Publisher: CRC Press
• Year: 2018
• ISBN:
  9781498764230
• Edition: 3
• Topic: Negocios y empresa
• Subtopic: Operaciones

This book is the leader among the new generation of text books on quality that follow the systems approach to creating quality in products and services; the earlier generations focused solely on parts of the system such as statistical methods, process control, and management philosophy. It follows the premise that the body of knowledge and tools documented by quality professionals and researchers, when employed in designing, creating and delivering the product will lead to product quality, customer satisfaction and reduced waste. The tools employed at the different stages of the product creation cycle are covered in this book using real world examples along with their theoretical bases, strengths and weaknesses.

This textbook can be used for training - from shop floor personnel to college majors in business and engineering to practicing professionals. Graduate students training as researchers in the quality field will also find useful material. The book has been used as the text for a Professional Series Massive Open Online Course offered by the Technical University of Munich on edX.org, through which tens of thousands of participants from all over the world have received training in quality methods. According to Professor Dr. Holly Ott, who chose the book for the course, the text is one of the main factors contributing to success of this MOOC.

The Third Edition has been fully revised to be friendly for self-study, reflects changes in the standards referenced such as ISO 9000, and includes new examples of application of statistical tools in health care industry.

Features:

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• Reviews the history of quality movement in the U.S. and abroad
• Discusses Quality Cost analysis and quality's impact on a company's bottom line
• Explains finding customer needs and designing the product using House of Quality
• Covers selection of product parameters using DOE and reliability principles
• Includes control charts to control processes to make the product right-the-first-time
• Describes use of capability indices Cp and Cpk to meet customer needs
• Presents problem solving methodology and tools for continuous improvement
• Offers ISO 9000, Baldrige and Six Sigma as templates for creating a quality system

1Introduction to Quality

We begin this chapter with a historical overview of how quality became a major, strategic, management and business tool in the United States and other parts of the world. We then explain the meaning of the term “quality”—a consensus definition of the term is necessary to discuss the topic and benefit from it. Then the need for a total quality system and an associated management philosophy for achieving quality in products is explained. The chapter concludes with a discussion on how quality impacts the economic performance of an enterprise, which includes a discussion on quality cost analysis. Detailed definitions of quality costs are provided, along with an explanation of how a quality cost study can be conducted. The usefulness of such a study in evaluating the quality-health of a system, and for discovering opportunities for quality improvement and reducing waste is explained.

1.1A Historical Overview

Striving for quality, in the sense of seeking excellence in one’s activities, has always been a part of human endeavor. History provides numerous examples of people achieving the highest levels of excellence, or quality, in their individual or collective pursuits. Shakespeare’s plays Beethoven’s music, the Great Pyramids of Egypt, and the temples of southern India are but a few examples. Quality appeals to the human mind and provides a sense of satisfaction, which is why most of us enjoy listening to a good concert, watching a good play, observing a beautiful picture, or even riding in a well-built car.

During the last 70 years, the term “quality” has come to be used in the marketplace to indicate how free from defects a purchased product is and how well it meets the needs of its user. After the Industrial Revolution in the early 1900s, mass-production techniques were adopted for manufacturing large quantities of products to meet the increasing demand for goods. Special efforts were needed to achieve quality in the mass-produced products when they were assembled from mass-produced parts. Variability or lack of uniformity in mass-produced parts created quality problems during parts assembly. For example, suppose a bearing and a shaft are to be assembled, chosen randomly from lots supplied by their respective suppliers. If the bearing had one of the smallest bores among its lot and the shaft had one of the largest diameters among its lot, they would not match and would be hard to assemble. If they were assembled at all, the assembly would fail early in its operation due to lack of sufficient clearance for lubrication. The larger the variability among the parts in the lots, the more severe this problem would be. Newer methods were therefore necessary to minimize this variability and ensure uniformity in parts that were mass produced.

Dr. Walter A. Shewhart, working for the former Bell Laboratories in the early 1920s, pioneered the use of statistics to monitor and control the variability in manufactured parts and products, and invented control charts for this purpose. Drs. Harold Dodge and Harry Romig developed sampling plans that used statistical principles to ascertain the quality of a population of products from the quality observed in a sample. These statistical methods, which were used mainly within the Bell telephone companies during the 1930s, were also used in the early 1940s in the production of goods and ammunition for the U.S. military in World War II. Some (Ishikawa 1985) even speculated that this focus on quality in military goods provided the United States and their allies an advantage that contributed to their eventual victory in the war.

After World War II, the U.S. War Department was concerned about the lack of dependability of electronic parts and assemblies deployed in war missions. From this concern grew the science of reliability, which deals with the failure-free performance of products over time. Reliability science matured during the early 1950s into a sophisticated discipline and contributed to improving the longevity, not only of defense products, but also of many commercial products such as consumer electronics and household appliances. The long life of refrigerators and washing machines, which we take for granted today, is in large measure the result of using reliability science in their design and manufacture.

During the early 1950s, leaders in the quality field, such as Drs. W. Edwards Deming, Joseph M. Juran, and Armand V. Feigenbaum, redefined quality in several important ways. First, they established that quality in a product exists only when a customer finds the product satisfactory in its use. This was in contrast to earlier views that a product had quality if it met the specifications set by the product designer, which might have been chosen with or without reference to the needs of the customer. Second, these gurus, as they were called, proposed that a quality product, in addition to meeting the needs of the customer in its physical characteristics, should also be produced at minimal cost. Finally, and most importantly, they claimed that, to create a product that will satisfy the customer both in performance and cost, a “quality system” was needed. This quality system would be made up of all the units of an organization that contribute to the production of a product. The system would include, for example, the marketing people who find out from the customers their needs, the designers who would design the product to meet those needs, the manufacturing engineers who design the processes to make the product according to the design, the workers who make the product, the packaging and shipping personnel who plan the logistics for delivering the product in proper condition, and after sale customer support who provide the customer help in assembling and using the product. There are many other components of the system as explained later in this ...