With fewer test defects, projects can address the quality aspects that customers feel are most important, Product and process quality thus go hand in hand. A heavy reliance on testing is inefficient, time-consuming, and unpredictable. Then, when the development groups finally stop testing, they deliver a poor quality product to the users. Though defects are only part of the quality story, they are the quality focus of the PSP. Defects are not the top priority, but effective defect management is essential to managing cost, the schedule, and all other aspects of product quality. Because defect result from errors by individuals, to effectively manage defects, you must manage personal behavior. You are the source of the defect in your products and you are the only person who can prevent them. You are also the best person to find and fix them.