Scheduling rules for a specific general purpose Flexible Manufacturing System (FMS) were investigated. The primary purpose of this research was to investigate effects and interactions of three types of scheduling rules on FMS performance. The rules included part scheduling on the machines and two resource allocation rules for tool scheduling and cart scheduling. Due to the numerous similarities in the scheduling and resource allocation problems of computer operating systems and the FMS, some techniques from operating systems were applied to the FMS to reduce thrashing, prevent deadlocks and increase cart utilization efficiency. A SLAM simulation model was developed to study the performance of the scheduling rules.