Fuzzy inference to assess manufacturing process capability with imprecise data

Process capability indices provide numerical measures on whether a process conforms to the defined manufacturing capability prerequisite. These have been successfully applied by companies to compete with and to lead high-profit markets by evaluating the quality and productivity performance. The loss-based process capability index Cpm, sometimes called the Taguchi index, was proposed to measure process capability, wherein the output process measurements are precise. In the present study, we develop a realistic approach that allows the consideration of imprecise output data resulting from the measurements of the products quality. A general method combining the vector of fuzzy numbers to produce the membership function of fuzzy estimator of Taguchi index is introduced for further testing process capability. With the sampling distribution for the precise estimation of Cpm, two useful fuzzy inference criteria, the critical value and the fuzzy P-value, are proposed to assess the manufacturi...

• Type: Journal
• Year: 2008
• Where: EOR
• Authors: Bi-Min Hsu, Ming-Hung Shu
• Keywords: EOR 2008, Process Capability, Process Capability Index, Taguchi Index