So far in this series we have looked at the underlying philosophy of Six Sigma and at the strategy and structure required for an effective Six Sigma implementation. Now we will delve into to the two main project methodologies used in Six Sigma: DMAIC and DMADV.
DMAIC is an acronym which stands for the five sequential phases of a process improvement project: Define, Measure, Analyze, Improve and Control. It is the most common framework for conducting Six Sigma projects, as it is used for making improvements to an existing process, service or product. DMAIC projects may be led by Green Belts, Black Belts or Master Black Belts.
In a systematic series of steps, project teams clarify the project goals and plan, confirm the details of the current process performance using data, identify and confirm potential root causes for performance problems, and implement effective improvements to counter those root causes. Finally in the Control phase, the team establishes procedures to ensure that the gains obtained are sustained.
The other main methodology for Six Sigma is Design For Six Sigma (DFSS), also known as DMADV. The five phases of DMADV are Define, Measure, Analyze, Design and Verify. Design projects are used to create new processes, products and services, and are typically led by Black Belts and Master Black Belts. Although the first few phases have the same names as the first steps of DMAIC, they are different.
Project teams first clarify the high-level goals of the new process, then delve into customer data to more specifically determine customer requirements and tie them to specific goals. Next the team identifies and evaluates potential means of fulfilling the requirements, selects one to implement, and creates the detailed design for the new process, product or service. Finally, the team rolls out the new process and confirms that it meets the established goals and requirements.
Typically a DFSS project is chartered when business leaders seek to establish a new service or product. However there are other instances when a Design project is initiated. Sometimes it is clear that though a service or product already exists, it is not meeting the business and customer needs, and would not be capable of doing so even with the incremental improvements that could be made via a DMAIC project. In this case a Design project is undertaken to establish a replacement that is capable of achieving the goals.
In other cases, a DMAIC project may be underway and the team uncovers data and limitations that make it clear that goals can not be met by merely working through the remainder of the DMAIC process. This may happen in the Improve phase when the team realizes that the best solution involves creating a new process, product or service. Or it may occur earlier in the project when measuring the current process, establishing customer requirements, or identifying root causes leads to the realization that something altogether new is required. In either case, any work that has already occurred through the DMAIC process can be used as part of the initial phases of DMADV to solidify understanding of the project goals and customer requirements.
In the next part of this series we will look at the tools and techniques that are commonly used as part of Six Sigma DMAIC and DMADV projects.