Evaluating Measurement Capability Based on Process Capability Index Cpk

• Main Authors: Pang-Yen Liu, 劉邦彥
• Other Authors: Jann-Pygn Chen
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/73207674782232176363

碩士 === 國立勤益技術學院 === 工業工程與管理系 === 94 === The measurement system analysis (MSA) is very important for quality improvement. A capable measurement system can be accurately to measure observed data. Normally, the evaluation standard of MSA by QS-9000 is used to judge the measurement capability. However, the current QS-9000 or ISO/TS16949 only refer to the acceptable range of P/T value, the relationship between Process capability index and P/T value had been rarely proposed. The thesis discusses the acceptable range of P/T value under satisfying customer’s Cpk requirement which considering process accuracy and precision. Firstly, the functional relation between Cpk and P/T value, Ca is derived. The approximate lower confidence limit of Cpk is used to determine the acceptable range of P/T value under observed Cpk values. To utilize the reasonal range to conduct a two factor experiment to evaluate if measurement system variation error is within the range. Finally, a case study is derived the implementing step of evaluating measurement capability.