Applying Process Capability Indices in Six Sigma

• Main Authors: Chang-Hsien Hsu, 許昌賢
• Other Authors: Kuen-Suan Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/76078284908611131527

博士 === 淡江大學 === 管理科學研究所博士班 === 95 === In 1970-1980’s, because of the promotion of Japanese product quality, makes it be popular to consumers in the international market; however, the marketing share of American products is decreasing in the worldwide. Motorola is many one of with Japanese manufacturer quality competition unfavorable situation companies, in order to retrieve the marketing share, it is proposed Six Sigma quality improvement strategies. In Six Sigma improvement, the measuring step is an extremely important procedure, in which number of Sigma is often a tool used in measuring the present quality level. But in the industry, Process Capability Index is another tool used to measuring process capability. The Six Sigma improving project of the enterprise uses number of Sigma integer to measure quality level, but the usage communicative language in the enterprise is the Process Capability Index. If the inner enterprise has not transformed number of Sigma into Process Capability Index value, then there will create the cognitive discrepancy in other enterprises on the quality. Therefore, this essay carries on a thorough research aiming at the relation between the number of Sigma and Process Capability Index in second chapter. In addition, the Process Capability Index can be also used directly in measuring step of Six Sigma improvement to measure the current process capability; however, many products all simultaneously have many quality characteristics, the product which the customer is willing to accept needs all process capabilities of each characteristic satisfy preset specifications. The single Process Capability Index can''t measure this kind of condition in the meantime; therefore, this essay in the third chapter. According to Chen et al.(2001) to develop MPCAC Model to measure the condition of several quality characteristics. MPCAC Model constructing out of Six Sigma is inducted into the measuring step of Six Sigma; further, MPCAC Model is led to Chou et al. (1990) under the construction sampling model. Finally, above MPCAC Mode will apply the improving process of Profile of Offset Ratchet Wrenches. Chapter 4 continues the concept of third chapter, with the basis of Process Capability Index Cpk, developing the PCAC model to evaluate process capability. PCAC mode can measure a product to have the condition of several quality characteristics in the meantime, and can judge the shortage of process capability for the reason of the precision or accuracy. PCAC Model constructing out of Six Sigma is inducted into the measuring step of Six Sigma; further, PCAC Model applying to sewing machine industry in Six Sigma improvement case is led to Chou et al. (1990) under the construction sampling model. Finally, PCAC Mode will apply the improving process of Profile of T-Handled Hex Key Driver.