Computer-aided process planning is an essential interface between computer-aided design and computer-aided manufacturing. In this thesis, a computer-aided process planning system - TIPPS is developed. A CAD design model is used for direct input in the TIPPS system. A boundary internal model of the engineering part drawing is displayed on a CRT screen, and using an interactive procedure, surface which require machining can be marked. A backward planning scheme searches a process knowledge database to find a sequence of manufacturing processes which can achieve the design specification. The process knowledge database consists of process description statements. A process description statement (mathematical terms are used) represents the capabilities of a single process. TIPPS also selects process parameters - feed and cutting speed automatically. TIPPS provides: 1) direct CAD interface, 2) external process capability description language, 3) modular structure, and 4) interactive surface identification. Various approaches used in designing and process planning are discussed. A review of CAD, process engineering, planning decision methods and current process planning systems is included. / Ph. D.