Diagnostic Quality Problem Solving: A Conceptual Framework and Six Strategies

Abstract

Diagnostic problem solving, which is the task of discovering causal explanations for unwanted effects, is an important element of problem solving. This paper contributes a conceptual framework for the generic process of diagnosis in quality problem solving by identifying its activities and how they are related. It then presents six strategies that structure the diagnostic process by suggesting a certain sequence of actions and techniques. The paper analyzes when each of these strategies is likely to be effective and how it may help in making the diagnostic process more efficient. Finally, the paper proposes and motivates a generic sequence of stages in diagnosing quality problems.The framework offers a scientific basis for studying and evaluating problem-solving methodologies such as Six Sigma's DMAIC model, Kepner and Tregoe's problem analysis method, and Shainin's system. For the practitioner, the framework clarifies the rationale for many problem-solving techniques offered in courses and textbooks. The paper also offers indications and contra-indications when techniques are promising, and demonstrates how they fit together in a coherent strategy.