M.T Moeti - Member of Young Researchers Club, Islamic Azad University, Arak branch, Iran
M Mashinchi - Faculty of Mathmatics and Computer Sciences, Shahid Bahonar University, Kerman, Iran
A Parchami - Faculty of Mathmatics and Computer Sciences, Shahid Bahonar University, Kerman, Iran

Process capability indices are used to measure the capability of a process to reproduce items within the specified tolerance preset by the product designers or customers. After introducing fuzzy onesided process capability indices PU C~ and PL C~ , we obtain fuzzy lower confidence bounds for the introduced indices, where instead of precise quality we have one triangular membership function for onesided specification limit.

Lower confidence bound; Fuzzy process capability indices; Ranking function