Minimum Setup Minimum Aberration Two-level Split-plot Type Designs for Physical Prototype Testing

Companies always seek strategies to shorten product development and reduce time-to-market. Although new technologies allow for less effort in prototyping, physical testing still remains an important step in the product development cycle. Well-planned experiments are useful to guide the decision-making process. During the design of an experiment one of the challenges is to balance limited resources and system constraints to obtain useful information. It is common that prototypes are composed of several parts, with some parts more difficult to assemble than others. And, usually, there is only one piece available of each part type and a large number of different setups. Under these conditions, designs with randomization restrictions become attractive approaches. Considering this scenario, a new and additional criterion to construct split-plot type designs is presented. Designs with a small number of setups of the more difficult parts, which are especially useful for screening purposes in physical prototype testing, are discussed. Theoretical properties of the designs are provided and it is shown how to appropriately analyze the data through a real application in testing car prototypes. As a tool to practitioners, catalogs of selected 32-run split-split-plot and split-split-split-plot designs are presented.