Application of trapezoidal fuzzy quality in the automobile manufacturing industry

Hypotheses testing is an effective technique for decision making on the manufacturing process capability. Considering fuzzy quality rather than precise specification limits, we can make more reliable decisions for investigating the manufacturing process capability. In this paper, an applied study on the basis of fuzzy quality using the Yongting’s index is presented. The proposed approach which is used in this applied study is a technique for testing the capability of a normal process in producing products within the preset fuzzy specification limits. The adversity to test process capability indices is complexity in the distribution of its natural estimator, even under the Normal distribution. Also, there is the challenge in testing process capability based on fuzzy quality. The non-parametric approach which is used to test the performance of a product based on fuzzy quality and random sampling techniques which is presented based on the Monte Carlo simulation method and can be generalized for various fuzzy qualities. This study is presented to investigate the quality of paint thickness in the automobile polishing process based on trapezoidal fuzzy quality. The numerical computations are presented to show the performance of the Monte Carlo simulation method for making reliable decisions in testing the Yongting’s index.