Capital-intensive facilities called
(“FABs” in short) are operated twenty-four hours a day to meet the massive orders on time. The main objectives of scheduling the complex manufacturing process are to meet the on time delivery and to maximize machine utilization. A discrete event simulation approach has brought good results to generate an efficient and practical schedule. However, the approach tends to make short-term decision, which loads any job rather than stays idle. When the setup time is long and the number of crews is limited, being idle could be a better decision than changing jobs. This paper proposes a method to compensate for the limitations of simulation-based schedulers. We propose a Gantt chart simulation approach that formulates WIP level with an
with the number of loaded machines. With two profiles, we can determine when to add or release a machine for each job. The proposed method has been applied to a real factory and showed promising results.