Optimization of machine flexibility in an ion plating cell

In 1970s, manufacturing system performance was heavily depended on productivity. Manufacturers only concentrated on increasing productivity by increasing the number of workforce. The concept of flexibility began to introduce into the industry since 1990s, manufacturers realized that flexibility was a better solution to improve productivity by responding the changing environment in manufacturing system. However, limited researches on machine flexibility in ion plating (IP) industry were studied, most of them have focused on product development and quality of coating. The aim of this paper is to determine the optimal level of machine flexibility in an ion plating cell (IPC) to improve the entire system performance. A machine loading sequencing (MLS) model based on multi-objectives genetic algorithms (GA) was developed. In the case study, industrial data of a precious metal finishing company has been input into the proposed machine loading sequencing genetic algorithm (MLSGA) model. Different level of machine flexibility will be assigned into different machines to determine the optimum while the overall system performance (i.e. on-time delivery, quality of product and production cost) has been maximized. The results demonstrated that the machine flexibility level in IPC should be zero under the recent IP technology. However, when the quality of coating is improved, machine flexibility should be introduced.