Robust design: A cost-effective method for improving manufacturing processes

Robust design is a method for making a manufacturing process less sensitive to manufacturing variations. Because it reduces variation by reducing the influence of sources of variation, not by controlling them, robust design is a cost-effective technique for improving process quality. The method uses small, statistically planned experiments to vary the settings of key process control parameters. For each combination of control parameter settings in the experiment, process performance characteristics are measured to reflect the effects of manufacturing variation. Then, simple plots or tables are used to predict the control parameter settings that minimize these effects. A small follow-up experiment confirms the prediction. This paper describes how to apply the basic robust design method to improve process quality.