Design for Six Sigma (DFSS) is used by businesses to design a quality product from scratch. Design for Six Sigma is fundamentally different from Six Sigma itself. The focus of Six Sigma is on improving the existing designs whereas the focus of DFSS is on creating new and better products. IDDOV in DFSS provides the necessary framework for product development and emphasizes the step-by-step phases to achieve Six Sigma, including Identify, Define, Develop, Optimize and Verify. It is described in detail here.
1. Identify the Opportunity -This is the phase where you identify the customer requirements, prioritize their needs, and translate those needs into design requirements. It is the most important phase of DFSS since all of the future activities of the projects depends on this phase. Once the requirements are identified, the complete project plan can be made. Ideally, the project plan consists of the scope of the project, project objectives, project milestones and the budget.
2. Define the Requirements – This is the phase where you clearly define the product requirements. In this phase, the customer needs and wants are translated into verifiable requirements. The primary tool used for this purpose is Quality Function Deployment (QFD). QFD is a method by which the customer needs or wants are converted into specific corporate goals so that product designers are aware of what exactly they should do.
3. Develop the Concept – This is the phase where you develop a feasible concept which will meet the customer requirements. If the concept developed is found to be unreasonable, then assess other alternatives. In this phase, any potential product failure is identified and thus, eliminated. The usual tools used during this phase are TRIZ (the theory for inventive problem solving), Pugh (a technique for evaluating and developing concepts), and FMEA (Failure Mode and Effective Analysis).
4. Optimize the Design – This is the phase where you optimize the design in such a way that the maximum output is obtained from the developed concept. In this phase, the critical design variables and functional parameters are determined to ensure utmost customer satisfaction.
5. Verify Conformance – Once optimization of the design is done, it is validated against established process controls and a complete cost-benefit analysis is done. In this phase, testing is done to verify that the product meets all the legal and environmental norms. Also, it is seen to it that there are no unexpected side effects. The three step process to ensure that the product is tested is to:
i) Verify the capability of the manufacturing process by verifying the capability of the manufacturing personnel, training processes, manufacturing processes, equipment, measurement systems, etc.
ii) Conduct a prototype testing wherein the prototypes of the product are released to customers and the quality of the product is thus determined.
iii) Conduct a pilot production run to verify the capability of manufacturing processes to deliver quality products at low costs.
The role of IDDOV in DFSS in corporations such as GE, Motorola, and Hyundai is notable. The IDDOV framework has helped these corporations to remodel their processes and to rebuild new products on the basis of DFSS.