Quality by Design

Quality by Design (QbD) is a concept first outlined by quality expert Joseph M. Juran in publications, most notably Juran on Quality by Design. Designing for quality and innovation is one of the three universal processes of the Juran Trilogy, in which Juran describes what is required to achieve breakthroughs in new products, services, and processes. Juran believed that quality could be planned, and that most quality crises and problems relate to the way in which quality was planned.

While Quality by Design principles have been used to advance product and process quality in industry, and particularly the automotive industry, they have also been adopted by the U.S. Food and Drug Administration (FDA) for the discovery, development, and manufacture of drugs.

The Juran Trilogy defines the word "quality" as having two meanings: first, the presence of features that create customer satisfaction; second, the reliability of those features. Failures in features create dissatisfactions, so removing failures is the purpose of quality improvement, while creating features is the purpose of quality by design. Juran's process seeks to create features in response to understanding customer needs. These are customer-driven features. The sum of all features is the new product, service, or process.

The Quality by Design model consists of the following steps:

It is not a statistical design method like Design for Six Sigma.

Integrated planning requires a team with a leader whose sole accountability is for the total success of the new product from defining the opportunity through customer purchase, use, service, and recommendation to others. This team leader reports directly to a senior executive, or the team leader can be a senior executive. Each team member's job is to ensure the success of the new product.

The team will follow a structured process. The structure is the common framework for all participants in launching the new product and helps ensure success.

Quality by Design starts and ends with the customer. Every new product introduction has some amount of trade-off involved. If there are multiple customers, they may have conflicting needs. Even the same customer may have needs that compete with each other. Capacity and speed compete with cost of operation. Capacity can compete with speed. Flexibility and feature-rich offerings may have reduced ease of use, and so on.

Quality by design offers a range of tools and methods intended to make these tradeoffs explicit and optimal for the customer. Some tools are highly mathematical, and others relate more to customer behavior. Quality by Design sets strong expectations for creative approaches to functional design, product features and goals, and production design.

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