The research discussed in this paper focuses on a modular fixture system to be used on a CNC machine in a flexible manufacturing system (FMS). The system developed in this research uses a robot to assemble the modular fixture. To command the robot a software program examines the CAD file of the workpiece and determines where location and clamping positions should be located on the fixture. Once the fixture design has been determined, the software system creates the proper robot program to retrieve the modular fixture components from a storage area and assembles the modular fixture. Next, the robot places the workpiece in the fixture and the pneumatic clamps are actuated to secure part in the fixture. When the processing of the workpiece is complete on the CNC machine, the robot removes the workpiece and inserts the next workpiece, or disassembles the fixture and returns fixture components to the storage area.