How does Six Sigma work?
Metrics lie at the heart of Six Sigma. The basic approach is to measure performance on an existing process, compare it with a statistically valid ideal and utilize various tools to figure out how to eliminate any variation and reduce the gap between ideal and current situation. Project teams might speak in terms of reducing cycle time, improving customer satisfaction, cutting down on returns and improving the speed and accuracy of order fulfillment.
Six Sigma teams use extremely rigorous data collection and statistical analysis to ferret out sources of errors and to find ways to eliminate them. The ultimate goal is to produce systems and processes that are as close to perfection as possible. Through classroom instruction, in-house support and deployment of the Six-Sigma tools throughout a business, one identifies and quantifies problems and then translates those problems into a mathematical equation with a solution for optimal performance. No project is considered complete until the benefit has been shown and a team of financial auditors signs off.
There are five steps of project execution
|1.Define:||Six Sigma project team—led by a green belt or black belt—identifies a project based on business objectives as well as customer needs and feedback. The team identifies CTQs (critical to quality characteristics) that the customer considers to have the most impact on quality. It also separates the “vital few” from the “trivial many” (the projects that will have the most impact versus those that could stand improvement but are not critical).|
|2. Measure:||The team identifies the key internal processes that influence CTQs and measures the defects currently generated relative to those processes.|
|3. Analyze:||The team discovers why defects are generated by identifying the key variables that are most likely to create process variation.|
|4. Improve:||The team identifies the maximum acceptable ranges of the key variables and validates a system for measuring deviations of the variables. The team modifies the process to stay within the acceptable range.|
|5. Control:||Financial auditors sign off on the accrued benefits then tools are put in place to ensure that the key variables remain within the maximum acceptable ranges over time.|