Failure mode and effects analysis using grey theory

Conventional FMEA determines a risk priority number by multiplying the scores of three factors. However, the scores are obtained from subjective linguistic assessment, and the relative importance of factors is not considered. To improve the effectiveness, this study applies the grey theory to the failure mode and effects analysis. The results show that grey theory is much easier and more unbiased than traditional FMEA, and it can enhance product reliability and process stability by discovering potential problems during the stages of the product design and process planning.