The use of effective software in Computer Aided Process Planning (CAPP) can contribute significantly towards cost reduction and improvement in production rate. The most important elements of CAPP is the ability to effectively evaluate various machining process sequences and the utilization of the most appropriate machining parameters including machines, tools and tool grades and tool angles, cutting fluids, cutting conditions, and cutting speeds and feeds. The evaluation can be done effectively utilizing MPSEL and VISUAL MACH, software that are based on expert systems and cost computing algorithms. MPSEL is an expert system based software tool that inferences based on backward chaining rules. VISUAL MACH is spread-sheet based software that accurately estimates production cost and production rate based on specific machining operational parameters and product design attributes. For the case studies illustrating the use of the software, a specific manufacturing process based infrastructure will be assumed with a repository of specific case studies will be discussed illustrating the use of the software to enable significant cost reductions and production rate increases for product designs. The sensitivity of production cost and production rate with respect to varying product, process, and system level parameters will be explored and conclusions derived.