Abstract
Process capability indices are widely used to evaluate the performance of processes in the manufacturing industry. Over the years, the issues have been investigated extensively. Some articles have studied them with fuzzy estimation. However, it seems that no article has proposed a version of triangular fuzzy numbers for critical value to test the process capability. In this article, we use Buckley's approach (Citation2003) to construct the triangular fuzzy numbers for C pl and C pu , especially, the triangular fuzzy numbers for critical values are derived to execute the fuzzy hypothesis testing for C pl and C pu . Some numerical examples are taken to illustrate the proposed methodology.