Hypothesis Generation in Quality Improvement Projects: Approaches for Exploratory Studies

In quality improvement projects—such as Six Sigma projects—an exploratory phase can be discerned, during which possible causes, influence factors or variation sources are identified. In a subsequent confirmatory phase the effects of these possible causes are experimentally verified. Whereas the confirmatory phase is well understood, in both the statistical sciences and philosophy of science, the exploratory phase is poorly understood. This paper aims to provide a framework for the type of reasoning in the exploratory phase by reviewing relevant theories in philosophy of science, artificial intelligence and medical diagnosis. Furthermore, the paper provides a classification and description of approaches that could be followed for the identification of possible causes. Copyright c © 2006 John Wiley & Sons, Ltd.