The CTQ flowdown as a conceptual model of project objectives

The purpose of this article is to describe and clarify a tool that is at the core of the definition phase of most quality improvement projects. This tool is called the critical to quality (CTQ) flowdown. It relates high-level strategic focal points to project objectives. In their turn project objectives are linked to and decomposed into CTQs, which are made operational in the form of measurements. In this article the nature of the connections between strategic focal point, project objectives, CTQs, and measurements is elaborated.
The CTQ flowdown serves several purposes. It provides clear project definitions, clarifies the business rationale of an improvement project, makes explicit business assumptions behind project definitions, helps to focus on the vital few real business drivers, and facilitates optimally solving trade-off problems. This article provides a theoretical grounding of the CTQ flowdown, and also provides practitioners with a prescriptive template.

Key words: balanced scorecard, key performance indicators, measurement, project definition, Six Sigma, tree diagram