This paper focuses on the issues in automating the various tasks in process planning and on the issues in integrating the process-planning task with commercial CAD/CAM software. Automated process planning involves two important tasks; machining feature extraction and feature-based process planning. The integration of CAD and NC may be done by two alternative approaches: external or internal. This study uses the external approach. The CAD model of the part and the stock is exported to a format compatible with the external geometry engine. The machining feature recognition system communicates with the external geometry engine through APIs to obtain geometric and topological information required for feature recognition. The machining knowledge embedded in the recognized features is used by the process-planner to chalk out a process plan for the part. The machining features are classified into three broad categories each with machining significance specific to NC machining, so that when extracted they are useful in making process-planning decisions. Setup Planning, Operation Sequencing and Tool Selection is performed automatically based on criteria such as feature shapes, feature locations, tool access directions and feasibility of workpiece locating and clamping. The detailed process planning is based on a commercial CAD/CAM/CAE package, I-DEAS.