Lot of guidelines and regulatory requirements are available for this topic and general steps in chronological orders are defined. However how to make them effective is question.
It is a requirement that all manufacturers must follow those requirements through establishing proper system within organization so that all devices produced are safe to use. Just to give you an example.
To ensure the standard of medical devices, the FDA(Food and Drug Administration) has laid down design control regulations for medical device manufacturers by incorporating them into the standard System Regulation, 21 CFR Part 820. These design controls are established to take care of the specified regulations and therefore the quality aspects of medical devices, like safety, performance, also as product dependability associated with software, hardware, services, or processed materials during the design and development phase.
Efficiency in the process comes only if concurrent engineering practices are put into place meaning involvement of Design people with engineering, manufacturing, and quality in each phase, so if correction is needed it is addressed there and then and not at later date.
an efficient implementation of those design controls lies in applying procedures and practices that suits the regulations while meeting technical specifications of the merchandise. Design phase has to take control of this, and team involved has to look from the basic steps that they are not only within regulation but also using best of their engineering practices.
Without going into details of each step the team must ensure that at each step the design is reviewed and tested when needed. User needs which is basic of all these things must be at the top of requirement.
Inter relationship amongst all steps are described in below diagram thus proving that all steps though are independent them selves but very much interrelated.

Design controls are often utilized in any medical product development process. the appliance process of design controls is showed within the below figure.

Processes of Design Controls
1. Design and Development Planning starts with user needs.
2. Design Input Based on user needs inputs gets defined.
3. Design Output after applying design process and engineering practice out put comes which has to meet input.
4. Design Review team’s responsibility to check all aspects.
5. Verification & Validation once completed, final testing and process validation proves design’s ruggedness.
6. Design Changes This is an integral part of industry. Over a period of time changes needed to make it better or improve on some issue did not noticed during all above steps.
Apart from all above documentation is very important and all steps covered above need to be documented and collated in one file called design history file.