Software normally used to assess the degree to which products are “assembly friendly” is now used to measure whether or not new designs are really improvements over the models they replace.

The software, a tool called Design for Assembly from Boothroyd Dewhurst Inc., Wakefield, R. I., is ordinarily used to simplify product designs by showing designers where to eliminate unnecessary parts, thereby simplifying assembly and lowering labor costs. But new-product development engineers at Motorola Solutions’ Holtsville, N. Y., design center used a calculation from the software called the DFA index as a key measure of overall product design. The index is simply an “ideal” assembly time divided by the actual assembly time. An ideal assembly is one having a theoretical minimum number of parts as determined by the DFA software.

Motorola engineers divided the company product portfolio into product families whose members were closely related by their technology. Engineers then figured a DFA index calculation for every product, computed averages for each product family, and ran the same calculation for competing products.

The resulting metrics served as a yardstick for gauging best-in-class design goals and a way to quantify whether designs were improving. Motorola personnel say DFA data gets compiled monthly and is presented to senior management. A product with a DFA index below target gets attention at all levels.

Resources: Boothroyd Dewhurst Inc., Motorola Solutions Inc.