The DMAIC process is a core component of the Six Sigma methodology. It is used when making improvements to an existing process. (For creation of new processes and products, the DMADV framework is followed.)
DMAIC is an acronym for the 5 key phases in a process improvement project: Define, Measure, Analyze, Improve, and Control.
In the Define phase, the project team clarifies the purpose and scope of the project and confirms that a DMAIC project is in fact appropriate. A key tool for this phase is the project charter. The project leader, typically a Black Belt or Green Belt, coordinates with team members and other stakeholders to compile the charter document. The charter should spell out the objective of the project, the expected timeline and budget, the scope, and the major players.
Also created during the Define phase is the SIPOC – a diagram which identifies the process being examined, the inputs to and outputs of the process, and the relevant suppliers and customers. This ensures that all team members understand the process itself at a high level.
Another important aspect of the Define phase is the gathering of VOC (Voice Of the Customer) data. Six Sigma is focused on finding out directly from customers what their idea of quality is, and how well the current process meets that standard.
During Measure, the focus is on gathering data to describe the current situation. It is critical to identify the appropriate process measures and gather sufficient baseline data, so that once improvements are made the impact can be verified empirically.
A detailed process map is created, including documentation of variations in how the process is carried out. With this information the project team can begin to see some of the factors that may be affecting process performance.
The purpose of the Analyze step is to determine the root causes of the process problems and inefficiencies. A variety of methods are used to identify potential root causes, narrow down the possibilities, and confirm the relationship between the suspected causes and the performance of the process.
Statistical analysis is a key component of this step, and is used to demonstrate these relationships.
The next step, Improve, involves establishing a means of countering the root causes. Techniques involve brainstorming, FMEA (Failure Modes and Effects Analysis), and piloting the improvement plan before rolling it out in full.
The same data that was obtained during Measure to establish the baseline is again gathered after improvements are in place. Data analysis and charting techniques are used to confirm that performance has in fact improved sufficiently to meet the project’s goal.
Finally in the Control phase, steps are taken to ensure that the gains obtained during Improve are maintained. Common tasks include setting up ongoing data tracking and a plan for identifying when the process performance starts to slip and taking appropriate action. At the end of this phase, the project manager transfers ownership back to the process owner, and the team communicates the project results to all stakeholders.
By following the Six Sigma DMAIC methodology, process improvement can be accomplished in a way that is systematic, sustainable, confirmed with data, and in alignment with customer and stakeholder quality expectations.