Quality Control Circles Technique for Reducing Fine Bored Parts Rejects After Tool Change

This study aims to assess reduction of rejects after tool change in a crankshaft manufacturing industry using Quality Control Circles (QCC) technique. Four months production data of crankshaft was collected and analyzed in 2022 in one of the largest automotive industries in Indonesia. Fine boring process was identified as the largest contributor of rejects. QCC activities were conducted to streamline the type of rejects in fine boring. QCC introduced a new intermediate action in calibrating machine setting after tool change. The results show a significant reduction in the level of rejection from 35% to just 5% of total rejects in the fine boring process after this QCC method was implemented. This result shows that this QCC method, by brainstorming among employees, can continuously improve and solve the problem in the workplace. This QCC method not just reduce the reject rate but also increasing morale, safety maintenance for employee, smoothness in supplying the next process, and reducing the cost (QCDSM). The limitation of this method is high dependency to the knowledge, experience and skill of the QCC team. Development of QCC team in term of new knowledge may lead to future improvement opportunity through development of quality control techniques with incorporation of internet of things or smart devices.