(1) A method that provides organizations tools to improve the capability of their business processes. This increase in performance and decrease in process variation lead to defect reduction and improvement in profits, employee morale and quality of products or services. Six Sigma quality is a term generally used to indicate a process is well controlled (+ / - 6s from the centerline in a control chart).
(2) A sophisticated problem solving methodology.
Six Sigma is a business management strategy originally developed by Motorola, USA in 1986, it is now widely used in many sectors of industry. Six Sigma seeks to improve the quality of process outputs by identifying and removing the causes of defects (errors) and minimizing variability 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", "Green 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 and/or profit increase).
The term Six Sigma originated from terminology associated with manufacturing, specifically terms associated with statistical modeling of manufacturing processes. The maturity of a manufacturing process can be described by a sigma rating indicating its yield, or the percentage of defect-free products it creates. A six sigma process is one in which 99.99966% of the products manufactured are statistically expected to be free of defects (3.4 defects per million). Motorola set a goal of "six sigma" for all of its manufacturing operations, and this goal became a byword for the management and engineering practices used to achieve it.
Six Sigma originated as a set of practices designed to improve manufacturing processes and eliminate defects, but its application was subsequently extended to other types of business processes as well. In Six Sigma, a defect is defined as any process output that does not meet customer specifications, or that could lead to creating an output that does not meet customer specifications.
Six Sigma requires that:
* Continuous efforts to achieve stable and predictable process results (i.e., reduce process variation) are of vital importance to business success.
* Manufacturing and business processes have characteristics that can be measured, analyzed, improved and controlled.
* Achieving sustained quality improvement requires commitment from the entire organization, particularly from top-level management.
* A clear focus on achieving measurable and quantifiable financial returns from any Six Sigma project.
* An increased emphasis on strong and passionate management leadership and support.
* A special infrastructure of "Champions," "Master Black Belts," "Black Belts," "Green Belts", etc. to lead and implement the Six Sigma approach.
* A clear commitment to making decisions on the basis of verifiable data, rather than assumptions and guesswork.
In recent years, some practitioners have combined Six Sigma ideas with lean manufacturing to create a methodology named Lean Six Sigma. The Lean Six Sigma methodology views lean manufacturing, which addresses process flow and waste issues, and Six Sigma, with its focus on variation and design, as complementary disciplines aimed at promoting "business and operational excellence". Companies such as IBM use Lean Six Sigma to focus transformation efforts not just on efficiency but also on growth. It serves as a foundation for innovation throughout the organization, from manufacturing and software development to sales and service delivery functions.
Six Sigma projects follow two project methodologies inspired by Deming's Plan-Do-Check-Act Cycle. These methodologies, composed of five phases each, bear the acronyms DMAIC and DMADV.
* DMAIC is used for projects aimed at improving an existing business process. DMAIC is pronounced as "duh-may-ick".
* DMADV is used for projects aimed at creating new product or process designs. DMADV is pronounced as "duh-mad-vee".
The DMAIC project methodology has five phases:
* Define the problem, the voice of the customer, and the project goals, specifically.
* Measure key aspects of the current process and collect relevant data.
* Analyze the data to investigate and verify cause-and-effect relationships. Determine what the relationships are, and attempt to ensure that all factors have been considered. Seek out root cause of the defect under investigation.
* Improve or optimize the current process based upon data analysis using techniques such as design of experiments, poka yoke or mistake proofing, and standard work to create a new, future state process. Set up pilot runs to establish process capability.
* Control the future state process to ensure that any deviations from target are corrected before they result in defects. Implement control systems such as statistical process control, production boards , visual workplaces, and continuously monitor the process.
DMADV or DFSS
The DMADV project methodology, also known as DFSS ("Design For Six Sigma"), features five phases:
* 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 owner(s).