Six Sigma is a business management strategy, originally developed by Motorola, that today enjoys wide-spread application in many sectors of industry.
Six Sigma seeks to identify and remove the causes of defects and errors in manufacturing and business processes. It uses a set of quality management methods, including statistical methods, and creates a special infrastructure of people within the organization (“Black Belts” etc.) who are experts in these methods. Each Six Sigma project carried out within an organization follows a defined sequence of steps and has quantified financial targets (cost reduction or profit increase).
DMAIC is used to improve an existing business process; DMADV is used to create new product or process designs.
DMAIC
The basic methodology consists of the following five steps:
* Define process improvement goals that are consistent with customer demands and the enterprise strategy.
* Measure key aspects of the current process and collect relevant data.
* Analyze the data to verify cause-and-effect relationships. Determine what the relationships are, and attempt to ensure that all factors have been considered.
* Improve or optimize the process based upon data analysis using techniques like Design of Experiments.
* Control to ensure that any deviations from target are corrected before they result in defects. Set up pilot runs to establish process capability, move on to production, set up control mechanisms and continuously monitor the process.
DMADV
The basic methodology consists of the following five steps:
* Define design goals that are consistent with customer demands and the enterprise strategy.
* Measure and identify CTQs (characteristics that are Critical To Quality), product capabilities, production process capability, and risks.
* Analyze to develop and design alternatives, create a high-level design and evaluate design capability to select the best design.
* Design details, optimize the design, and plan for design verification. This phase may require simulations.
* Verify the design, set up pilot runs, implement the production process and hand it over to the process owners.