Automated fixture design has become a research focus in process planning and CAD/CAM integration. An automated fixture configuration design system has been developed where when fixturing surfaces and points are specified, modular fixture components can be automatically selected and placed into position with satisfying assemble conditions. A geometric analysis has been conducted to determine the fixturing surfaces and points which provide feasible geometric constraints and assembly relationships with modular fixtures. This paper presents analyses on fixturing accuracy, clamp planning, fixturing accessibility, and clamping stability. When a fixture planning is determined, the analysis results can be applied to verify the performance of the fixture design.