... swapped the diaphragm from the good unitto the bad and vice versa, the good unit stayed good, the bad stayed bad. There-fore, the diaphragm was not the problem. The same happened when the cap-stan ... destroyingthem.Sample Size Six or eight good units and six or eight bad units, with as large adifference between them as possible.Methodology Select six or eight of the best and six or eight of the ... group of customers with similar needs. The trend, withmass customization, is going the other way. ■ The way QFD gathers customer requirements can be flawed.■ The amassing of more than forty customer...