It is now widely accepted that the final cost of a manufactured product is largely determined at the design stage. This work addresses decisions that must be made early in design; namely the selection of suitable processes and materials for the proposed component parts of the product. However, designers will tend to conceive parts in terms of the processes and materials with which they are familiar and may, as a consequence, exclude from consideration process/material combinations that may have proved more economic. A satisfactory method for the systematic selection of suitable process/material combinations for part manufacture is not currently available. Such a method and its implementation in a computer environment for use at the early stages of product design are developed.