Computer Aided Process Planning (CAPP) as a significant part of the overall automation of manufacturing activities has received much research attention in both academia and industry in the past twenty years. There are two approaches to the automation of process planning: variant and generative. The variant approach is older and is based on the assumption that for a given part design there may be some similar parts that have been produced in the past. The logical way to produce the new process plan is to look at a similar one and modify it to satisfy the new design requirements. The generative approach uses a different method.