A Practical Approach for Testing the Process Quality

Process capability index Cpk is the most widely
used index in making managerial decisions since it provides bounds
on the process yield for normally distributed processes. However,
existent methods for assessing process performance which
constructed by statistical inference may unfortunately lead to fine
results, because uncertainties exist in most real-world applications.
Thus, this study adopts fuzzy inference to deal with testing of Cpk .
A brief score is obtained for assessing a supplier’s process instead of
a severe evaluation.

• Mou-Yuan Liao
• Chien-Wei Wu
• Chien-Hua Lin

• Process capability analysis
• quality control.

<p>[1] Chen TW, Chen KS, Lin JY (2003) Fuzzy evaluation of process
capability for bigger-the-best type products. International Journal of
Advanced Manufacturing Technology 21: 820-826.
[2] Chen TW, Lin JY, Chen KS (2003) Selecting a supplier by fuzzy
evaluation of capability indices. International Journal of Advanced
Manufacturing Technology 22: 534-540.
[3] Lin PC, Pearn WL (2004) Testing process performance based on the
capability index with critical values. Computers and Industrial
Engineering 41: 351-369.
[4] Zadeh LA (1965) Fuzzy sets. Information and Control 8: 338-353.
[5] Klir GJ, Yuan B (1995) Fuzzy Sets and Fuzzy Logic: Theory and
Application, Prentice-Hall Inc.
[6] Mamdani E, Assilian S (1975) An experiment in linguistic synthesis with
a fuzzy logic controller. International Journal of Man-Machine Studies, 7:
1-13.</p>