A difficult task in concurrent engineering tasks is to provide appropriate manufacturability feedback to the designer in a timely manner. Many tools provide designers with cost and manufacturability evaluations, but they do not necessarily help the designer to identify what aspects of the design to change in order to improve it from a manufacturing perspective. A computer-assisted concurrent-engineering technology is described which identifies cost-critical tolerances in the design and generates cost-reducing design suggestions. The purpose of the system is to help focus the designer’s attention on the specific aspects of the design that influence manufacturing cost. This can aid the designer in optimizing the manufacturing costs of prismatic, one-off parts created on a CNC machining center. This work uses a program called the Manufacturing Evaluation Agent to produce cost-reducing design suggestions. The Manufacturing Evaluation is made up of two portions: a manufacturing planner and a suggestion generator. The manufacturing planner, P3, takes a design and generates a manufacturing constraint net that represents all manufacturing steps and their sequencing. Each constraint in the network has a label indicating the portions of the design (or manufacturing environment) that gave rise to that constraint. The Suggestion Generator analyzes the manufacturing constraint net to find the cost-critical areas, and uses the labels to find the portions of the design responsible for these cost-critical parts of the manufacturing plan. By pinpointing the cost-critical areas of the design and suggesting alternatives, the Manufacturing Evaluation Agent can help the de-signer to more quickly develop a superior design. This results in more rapid turnaround time, lower cost designs, and fewer engineering change orders once the design is sent to the factory floor.