Nowadays, the development of manufacturing industries still relies heavily on research into manufacturing processes and materials and the development of new products. In addition to the traditional competition requirements for low cost and high quality, the competition pressure for today’s manufacturing industries are more complex products, shorter product life cycle, shorter delivery time, more customized products and fewer skilled workers. Today’s products are becoming much more complex and difficult to design. Tow fundamental manufacturing processes have been used Subtractive manufacturing (SM) and Additive Manufacturing (AM). SM is the process of cutting material from a block to produce designed part from 3-D, 2-D model or G-Code. The introduction of 3-D complex surface modeling software programs took the place of writing codes. Unlike CNC machines of the 1940s, today’s CNC machines are highly automated using CAD/CAM programs. AM is defined as the process of joining materials by either fusing, binding or solidifying materials such as liquid resin and powders usually layer upon layer to produce an object from 3-D model data. Terms such as 3-D printing, rapid prototyping, direct digital manufacturing, rapid manufacturing and solid freeform fabrication are often used to describe AM processes. AM processes are driven by 3-D computer data, or stereo-lithography (STL) files, which contain information on the geometry of the object. Additive Manufacturing is efficient for low volumes production, high design complexity and frequent changes. Hybrid manufacturing processes are carried out in either parallel or serial manner with the objective of enhancing their advantages whilst minimize their disadvantages. The hybrid manufacturing processes satisfied significant improvement in tool life, material removal rate, dimensional and geometric accuracy, and reducing production times.  Absence of proper Computer Aided Process Planning systems (CAPP) restrict utilizing additive/subtractive manufacturing in many industrial applications due to the complexly in designing systems inputs from the design phase. Therefore, this thesis aims to develop a CAPP system for additive/subtractive manufacturing for prismatic parts.