個案總覽

Product "robustness" is a function of good design. Still, most traditional quality programs concentrate on the factory. Zero Defects says that when parts come in within tolerances, the product will be fine. But parts just within tolerances have no advantage over those that just miss; it is better to miss a target consistently than to hit it haphazardly. Robust products maximize "signal-to-noise" ratios of component parts. Product designers can maximize these ratios by running experiments according to orthogonal arrays, which reckon the average effect of each variation on all other variations.

Manufacturing companies striving to compete on quality must design products that not only are technically elegant and manufacturable but also reflect customers' desires and tastes. For optimal results, marketers, designers, engineers, and strategists should work closely together from product conception to end result. A Japanese innovation, the house of quality, can help get interfunctional-team conversations started. Presented here in clear, step-by-step exhibits, the house is a conceptual map on which interdisciplinary teams can display and organize the evidence they need to set targets for design. Once all relevant facts are on the grid, the team makes its choices. The process has clarified opportunities, stimulated negotiation, and helped set an agenda. And the format is flexible. Once engineering targets have been set, the team can draw up new houses.