Flexible Manufacturing System (FMS) is an automated manufacturing system that incorporates all the relatively individual processing stations (CNC machines) within the production plant. FMS is fundamental of reducing cost, rising reliability and coordination of flexibility, and productivity. This paper considers the simulation study in the efficiency of multi-sections FMS to perform the various types for several part operations in terms of maximize throughput, WIP and waiting time with alternative routes selection by synthesizing dispatching rules. The study will also focus on the reused modules building functionality. Modeling efforts can be reduced to a great extent through the development of domain specific modules that encapsulate the domain-specific logic and hide many of the modeling details. The key feature of this conception is to allow user to define new modeling modules that can be tailored to a specific problem domain.