Determining the Cause of Quality Problems: Lessons from Diagnostic Disciplines

Diagnosis is a critical task in solving many quality problems. Since it is important in other fields of professional practice, diagnosis has been the target of considerable scientific study. This article brings the findings of research on diagnosis to the attention of quality practitioners and researchers. It presents a coherent, comprehensive account of diagnosis that is prescriptively oriented. Philosophical studies of the nature and types of causality are reviewed, as is research on the diagnostic process. Diagnostic tasks, strategies, and errors are discussed. Popular diagnostic techniques are assessed, informal heuristics that are central to diagnostician expertise are identified, and the use of taxonomies of causes is considered. The author lays the groundwork for practical and theoretical advances in the diagnosis of quality problems.