Optimization of tool change timing in a nut forming process using genetic algorithms

In this study, we consider an optimization problem arising from tool change scheduling of a nut forming process. The process has nine punches with different life spans. The objective of the study is to optimize the tool change timing of the nine punches in order to maximize the production yield. The punch life spans can be extended by means of Ti coating, but coated punches are more expensive. We also evaluate whether it is worth using coated punches. A cost model is developed for the nut forming process. In the developed cost model, we consider the reliability of the nine punches, the periods taken for changing punches, scrap cost and production yield. The cost function for the process is complex, and is difficult to be solved using conventional optimization methods. Therefore, genetic algorithms are used to solve the problems. We have developed our own genetic algorithms using Java programs and applied the developed genetic algorithms to provide solutions to the optimization problem.