Six Sigma

Six Sigma is a set of practices originally developed by Motorola to systematically improve processes by eliminating defects. A defect is defined as nonconformity of a product or service to its specifications.While the particulars of the methodology were originally formulated by Bill Smith at Motorola in 1986, Six Sigma was heavily inspired by six preceding decades of quality improvement methodologies such as quality control, TQM, and Zero Defects. Like its predecessors, Six Sigma asserts the following: Continuous efforts to reduce variation in process outputs is key to business successManufacturing and business processes can be measured, analyzed, improved and controlled Succeeding at achieving sustained quality improvement requires commitment from the entire organization, particularly from top-level management The term "Six Sigma" refers to the ability of highly capable processes to produce output within specification. Six Sigma's implicit goal is to improve all processes to that level of quality or better.

Methodology

Six Sigma has two key methodologies: DMAIC and DMADV:

• DMAIC is used to improve an existing business process;


• DMADV is used to create new product or process designs for predictable, defect-free performance.

DMAIC

Basic methodology consists of the following five steps:

• D - Define the process improvement goals that are consistent with customer demands and enterprise strategy.


• M - Measure the current process and collect relevant data for future comparison.


• A - Analyze to verify relationship and causality of factors. Determine what the relationship is, and attempt to ensure that all factors have been considered.


• I - Improve or optimize the process based upon the analysis using techniques like Design of Experiments.


• C - Control to ensure that any variances are corrected before they result in defects. Set up pilot runs to establish process capability, transition to production and thereafter continuously measure the process and institute control mechanisms.

DMADV
Basic methodology consists of the following five steps:

• D - Define the goals of the design activity that are consistent with customer demands and enterprise strategy.


• M - Measure and identify CTQs (critical to qualities), product capabilities, production process capability, and risk assessments.


• A - Analyze to develop and design alternatives, create high-level design and evaluate design capability to select the best design.


• D - Design details, optimize the design, and plan for design verification. This phase may require simulations.


• V - Verify the design, set up pilot runs, implement production process and handover to process owners.

Other Design for Six Sigma methodologies:

DMADOV (Define, Measure, Analyze, Design, Optimize and Verify) General Electric

DMEDI (Define, Measure, Explore, Develop and Implement) PricewaterhouseCoopers