Design of Experiments (DOE) Overview
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In industry, designed experiments can be used to systematically investigate the process or product variables that influence product quality. After you identify the process conditions and product components that influence product quality, you can direct improvement efforts to enhance a product's manufacturability, reliability, quality, and field performance.

For example, you may want to investigate the influence of coating type and furnace temperature on the corrosion resistance of steel bars. You could design an experiment that allows you to collect data at combinations of coatings/temperature, measure corrosion resistance, and then use the findings to adjust manufacturing conditions.

Because resources are limited, it is very important to get the most information from each experiment you perform. Well-designed experiments can produce significantly more information and often require fewer runs than haphazard or unplanned experiments. In addition, a well-designed experiment will ensure that you can evaluate the effects that you have identified as important. For example, if you believe that there is an interaction between two input variables, be sure to include both variables in your design rather than doing a "one factor at a time" experiment. An interaction occurs when the effect of one input variable is influenced by the level of another input variable.

Designed experiments are often carried out in four phases: planning, screening (also called process characterization), optimization, and verification. For examples of creating, analyzing, and plotting experimental designs, see Examples of designed experiments.