Section 3 Taguchi’s Methods versus Other Quality Philosophies Taguchi’s Quality Engineering Handbook. Genichi Taguchi, Subir Chowdhury and Yuin Wu Copyright © 2005 Genichi Taguchi, Subir Chowdhury, Yuin Wu. Quality Management 39 in Japan 39.1. History of Quality Management in Japan 1423 Dawn of Quality Management 1423 Period Following World War II 1424 Evolution from SQC to TQC 1426 Diffusion of Quality Management Activity 1427 Stagnation of Quality Management in the Second Half of the 1990s 1428 39.2. Quality Management Techniques and Development 1428 Seven QC Tools and the QC Story 1428 Quality Function Deployment to Incorporate the Customers’ Needs 1430 Design of Experiments 1431 Quality Engineering 1435 References 1440 39.1. History of Quality Management in Japan The idea that the quality of a product should be managed was born in Japan a Dawn of Quality long time ago. We can see some evidence that in making stone tools in the New Management Stone Age, our ancestors managed quality to obtain the same performance around 10,000 years ago. In the Jomon Period, a few centuries before Christ, earthenware were unified in terms of material and manufacturing method. In the second half of the Yayoi Period, in the second or third century, division of work (specialization) occurred in making earthenware, agricultural implements, weapons, and ritual tools. After the Tumulus Period, in the fourth or fifth century, the governing or- ganization summoned specialized engineers from the Asian continent and had them instruct Japanese engineers. For the geographical reason that Japan is a small country consisting of many archipelagoes, this method of convening leaders from technologically advanced foreign countries has been continued until the twentieth century. Japan did not document these techniques before the twentieth century. The major reason for this is that numerous technologies were imported from overseas, and superb technologies, such as the manufacture of Japanese swords, were in- herited through an apprenticeship system. In Japan, technological inheritance Taguchi’s Quality Engineering Handbook. Genichi Taguchi, Subir Chowdhury and Yuin Wu 1423 Copyright © 2005 Genichi Taguchi, Subir Chowdhury, Yuin Wu. 1424 39. Quality Management in Japan often relies more on ‘‘learn, steal, and realize’’ than on ‘‘instruct or communicate.’’ In fields other than manufacturing [e.g., Judo, Kendo (swordsmanship), Kado (flower arrangement), or Sado (tea ceremony)], Japanese leaders give detailed instructions to apprentices and make them learn the reasons for themselves. This is regarded as one of the most typical instructional methods in Japanese culture. Another instructional method relied on masters leaving know-how to descendants in the next generation (called ‘‘ogisho’’). These were considered not modern com- mentaries or manuals but difficult-to-comprehend documents that could be un- derstood only through repeated discipline. Therefore, even if a superb technology was born, it was not spread widely and did not boost the total technological level. Even after the Meiji Era arrived in 1868 after the Edo Shogunate was toppled, the major methods of technological innovation were introduced through foreign doc- uments or importation of engineers. In the area of scientific quality management, quite a few technologies were introduced. In 1931, when Shewhart completed Economic Control of Quality of Man- ufactured Product, the Shewhart control chart began to be used in the manufactur- ing process for light bulbs. It was in 1935 when the design of experiments, pioneered by Fisher, was first utilized in Japan. Even under the militaristic regime during World War II, which suppressed research activities, translation of bibliog- raphies by Carl Pearson was continued and a Japanese-unique sampling inspection chart was invented by Toshio Kitagawa. By the end of the war, statistical methods were being applied to production processes in some military plants [1,2]. Never- theless, as a whole, quality management levels in manufacturing products, except for craft products such as pottery or lacquerware, was not so high; therefore, ‘‘if it’s cheap, it’s bad’’ symbolized prewar Japanese products. Period Following Many books have already detailed quality management in Japan after the war. In World War II 1946, the GHQ of the Allied Forces summoned experts in statistical research from the United States to study required resources and telecommunication network systems needed for reviving Japan. The investigation significantly stimulated Jap- anese statisticians and quality management researchers. In 1950, W. Edwards Dem- ing, a U.S. specialist in sampling theory and statistical quality management, instructed Japanese quality management researchers in statistical quality manage- ment. His key advice was: (1) product development and production is an endless cycle (shown in Figure 39.1), and by repeating this cycle, we can advance our products and corporate activity to produce them (this cycle is called the Deming cycle in Japan); and (2) statistical procedures can be applied to various stages in corporate management. After his instruction in Japan, various companies put his advice into practice. Based in part on money, Deming donated from royalties on the textbook used for his lectures, the Deming Prize was founded in 1951 [3]; it is still awarded to companies that accomplish significant results through strenuous quality manage- ment. The first companies to win the prize in 1951 were Yahata Steel, Fuji Steel, Showa Denko, and Tanabe Seiyaku. Since the Deming Prize played an essential role in developing Japan’s industry worldwide, it was regarded as ‘‘the Messiah’’ in Japan’s industries. Between the end of the war and the 1960s, statistical quality management meth- ods, developed primarily in Europe and the United States, were studied vigorously and subsequently adopted by many companies and formulated as the Japan In- dustry Standards (JIS). In this period, companies focused mainly on introducing 39.1. History of Quality Management in Japan 1425 Figure 39.1 Deming cycle statistical methods such as the Shewhart control chart, statistical testing, sampling inspection, and Fischer’s design of experiments. It is often dubbed the SQC (sta- tistical quality control) period. While the Shewhart control chart [4] (Figure 39.2) contributed considerably to the production process, it brought about another result. The fundamental man- agerial concept behind the control chart—that we should recognize that any type 310 UCL = 305.4 X 300 X = 291.5 290 Average, Average, 280 LCL = 277.6 Figure 39.2 X-R control chart 30 R UCL = 27.3 20 Range, R = 12.9 10 NumberNumber of LotsLots 1426 39. Quality Management in Japan of job always has variability, define a normal result using past data, determine control limits for an abnormal state, monitor the result once an abnormality hap- pens, start an investigation, find the cause, and take corrective measures— contributed much to general management. Based on the Deming cycle illustrated in Figure 39.1, the management cycle (PDCA cycle) was invented and used repeatedly to improve business. The ‘‘P’’ in PDCA represents ‘‘plan,’’ to plan how we implement a job and what results we attain before working on the job. The ‘‘D’’ ‘‘Do,’’ to fulfill the job as planned. The ‘‘C’’ represents ‘‘check,’’ to check whether or not we have accomplished the same result or followed the same process as scheduled. The ‘‘A’’ represents ‘‘action,’’ to analyze the cause and take measures if the result has not been achieved. Since this cycle is applicable not only to management and improvement of the production process but also to many other kinds of businesses, job improvement based on quality management has started to spread. The PDCA cycle (Figure 39.3) has been emphasized as a key method in TQC (total quality control), in line with Shewhart’s concept of management. In 1954, J. M. Juran, an advisor in the American Management Association at that time, was invited to Japan by Japanese quality management researchers. In Juran’s lectures and instructions, statistical methods as one of the pillars of modern quality management were not mentioned. On the contrary, managerial aspects of quality management were stressed. Although this concept was implemented by Feigenhaum in the United States, it stood out as total quality control (TQC) in the second half of the 1960s in Japan. Evolution from SQC In the 1960s, trade in products such as automobiles, machinery, and electric ap- to TQC pliances, all of which had been protected by the Japanese government during Japan’s postwar rehabilitation period, was liberalized. Although quality manage- ment activity was reinforced to make the products more competitive, it was nec- essary to enhance products’ attractiveness as well as their quality. Therefore, all departments from product planning to sales, or all hierarchical people from top management to manufacturing operators, were encouraged to participate in qual- ity management activity, and at the same time, interdepartmental activity was re- inforced. This was TQC (later changed to TQM). B. Plan Figure 39.3 PDCA cycle 39.1. History of Quality Management in Japan 1427 TQC stresses not only presentation of the PDCA as top management’s policy and deployment of the policy to middle management in charge of a core of cor- porate administration but also companywide promotion of job improvement. To filter the job improvement activity down to bottom-level employees, the QC circle was introduced and subsequently spread nationwide. The QC circle, founded by the Japanese Union of Scientists and Engineers in 1962, contributed tremendously to quality improvement. The other characteristic of TQC was to synthesize quality management proce- dures by introducing quality assurance and reliability management, which had been pioneered in the United States. The concept of quality assurance, including compensation to customers, was introduced to solve the problems caused by huge complicated public systems or their failures. The mileage assurance for automo- biles was a typical example. Since indemnification incurred by system failures di- minishes corporate profit, each company was urged to reduce system failures.