Design controls are an integral component of a comprehensive quality system that covers the life of a device. The assurance process includes a total systems approach from the development of device requirements through design, production, distribution, use, maintenance, and, eventually, obsolescence. Design control starts with the development and approval of design inputs and includes designing a device and the associated manufacturing processes. Design control focuses on all aspects of designing a product and the implementation of the design. Some of the tools and techniques that can be used are described in the guidance. Although aspects of their utility are sometimes described, they are only included in the guidance for illustrative purposes.