Treasure Chest of Six Sigma Growth Methods, Tools, and Best Practices: A Desk Reference Book for Innovation and Growth

The Anatomy of Quality Loss in a Product

By Bill Jewett

For some time companies have prioritized problems with the quality of their products by using the “cost of poor quality” (COPQ) as the metric. This might be measured as the cost of repair or replacement. The concept of “quality loss” reaches beyond the COPQ to include additional costs suffered by customers, producers, and potentially by communities, when the performance of products deviates from its intended requirements, particularly by large amounts. These broad economic consequences serve to place more emphasis on stabilizing performance. The mathematical relationship, termed the “Quality Loss Function,” provides analytical criteria for decisions about the funding of improvements, either ...