A flexible manufacturing system (FMS) is a highly automated GT machine cell, consisting of a group of processing workstaions (usually CNC machine tools),interconnected by an automated material handling and storage system , and controlled by a distributed computer system. The reason the FMS is a called flexible is that it is capable of processing a variety of different part styles simultaneously at the various workstations, and the mix of part styles and quantities of production can be adjusted in response to changing demand patterns. The FMS is most suited for the mid-varitety, mid-volume production range.

The initials FMS are sometimes used to denote the tern flexible system . The machining process is presently the largest application area for FMS technology. Accordingly, an FMS is designed to produce parts (or products) within a defined range of styles, sizes, and processes.