Six Sigma is an integrated, disciplined proven approach for improving business performance.
DMAIC stands for Define - Measure - Analyze - Improve - Control. Six Sigma is management methodology driven by data.
1. Six Sigma focuses on projects that will produce measurable business results. For example GE Capital saved $2 Billion in 1999 using Six Sigma.
2. Six Sigma is based upon improving processes by understanding and controlling variation, thus improving predictability of business processes.
The Six Sigma DMAIC method is about "solving a problem with an unknown solution." The problem (the "Y") needs to be defined in concrete measurable terms with an operational definition. In the Define phase, the Six Sigma project team identifies a project based on business objectives and the customers of the process and their needs and requirements. The team identifies these as CTQs (critical to quality characteristics) that have the most impact on quality - separating the "vital few" from the "trivial many" - and creates a map of the process to be improved.
"Six Sigma has the power to vastly improve processes. Don't waste these valuable resources. Identify and understand how you deliver on the promises of your brand and deploy your Black Belts intelligently where they are needed. The use of Y = f(x) analysis is one proven way to gain insight into an organization. If you don't understand how to deliver to your customers, eventually they will find someone who does!"
The Belt leading the project determines both the initial capability and stability of the project Y, and determines the ability to measure the Y. Once the project has a clear definition with a clear measurable Y, the process is studied to determine the Key Process Steps and the Key Inputs for each process. After the Key Input list is established, the Belt will consider the potential impact on CTQ that each input has with respect to the defects currently generated in the process. Key Inputs are prioritized to establish a short list to study in more detail. With a prioritized list of inputs in hand the Belt will determine the potential ways the process could go wrong or how the input could go wrong. The best method to do this is an FMEA. Once the reasons for input failure are determined, preventative action plans are put into place.
Another big part of the Measure phase is beginning with proper metrics. Valid and reliable metrics to monitor the progress of the project are established during the Measure phase. Business Process Charting is the best way to track project metrics.
Through analysis the team can determine the causes of the problem that needs improvement and how to eliminate the gap between existing performance and the desired level of performance. This involves discovering why defects are generated by identifying the key variables that are most likely to create process variation.
A common error people make when they discuss the Six Sigma process is they think the DMAIC process takes too long to accomplish improvements. This is far from the truth; often "quick hits" are established early in the project and frequently already implemented by the time the team reaches the Analyze phase. If the team has not already identified major improvements then the breakthrough often results from careful process analysis with data. Six Sigma analysis techniques are the proper tools to uncover more difficult solutions.
This phase is often the most fun and at the same time the most difficult. Once problem causes are determined in the Analyze phase the team finds creative new improvement solutions. More often than not simple process experimentation and simulation bring the team big gains in this step.
The team also identifies what will happen if needed improvements are not made and what will happen if the improvements take too long.
Success in this phase depends upon how well we did in the previous four phases. If we used proper change management methods starting with identifying key stakeholders we should be on the way to success. In the Control phase tools are put in place to ensure that the key variables remain within the acceptable ranges over time so that process improvement gains are maintained. The team develops a project hand off process reaction plans, and training materials to guarantee performance and long-term project savings.
Finally, the team identifies what the next steps are for future Six Sigma process improvement opportunities.