E-CAFFS is a rule-based expert system for fixturing on a CAD system using flexible fixtures. It accomplishes the automatic layout of fixture models on a CAD/CAM system for given applications through an interative process. The final fixtured simulation is graphically represented as solid models on the screen of a computer-aided design system. This paper focuses on the fixturing of planar polyhedral workpieces for face-milling operations and predicts the feasibility of a generalized expert fixturing strategy on CAD systems. The software developed as a result of this research has decreased fixturing costs by a substantial amount and has successfully reduced fixturing down-time to a mere fraction.