Blower and vacuum pump scheduling is utilized in the model to reduce the capital cost while maintaining the system within physically reasonable bounds. In short, to minimize the capital cost of blowers and vacuum pumps, many modules can be centralized around one blower and vacuum pump. A group of modules that share blower(s) and vacuum pump(s) will be referred to as a cluster. However, the centralized design can lead to unintended downtime for modules without proper vacuum pump placement and scheduling, illustrated in Fig. . Module downtime reduces the plant utilization and therefore increases the total cost. To mitigate these problems, we designed a vacuum pump schedule for a cluster containing 20 modules, one blower, and two vacuum pumps (Fig. ).