A Fuzzy Approach Regarding the Optimization of Statistical Process Control through Shewhart Control Charts

The main goal of most organizations, no matter of their nature, object or size, is to be competitive as possible on the market, a crucial factor in ensuring a long operating duration. Unfortunately, the appearance of variation is a very bad and undesirable thing that determine a decrease in the companies productivity. Managing and providing a better view competitiveness can not be given unless we use some statistic models. This models’ variables follow closely each step of the process. If in the past years the issue of the control managing of a process wasn’t seriously taken into consideration, today more things like more pretentious customers or the growth of the competitiveness level on the products and logistics market, made almost all companies to hire people, especially for the control of the quality. They have to check not only the final products but also the intermediate stages of the process. The aim of this paper is to realize a fuzzy approach based on statistical control techniques concerning on Shewhart control charts. The relationship between statistical process control and fuzzy modeling is a very researched field because the sensitivity of the fuzzy systems is an important advantage in quality analysis of the production process. Index Terms — statistical process control, control charts, special causes, fuzzy logic, double warning limit