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Sustaining quality improvements
Laurel Thoennes Published: 06/22/2009
Define, measure, analyze, improve, control (DMAIC), developed by W. Edwards Deming in the 1950s, is a statistical and analytical method used to reduce defects by finding the root causes of defects, eliminating them, and sustaining that improvement level.
The roots of DMAIC are from the plan-do-check-act (PDCA) cycle, a method for learning and improvement, also referred to as the “Shewhart Cycle,” developed by Walter Shewhart, the statistician who developed statistical process control (SPC) while employed at Bell Laboratories during the 1930s.
Deming successfully applied the concept of PDCA to the management system processes of industrialized organizations during the 1950s and PDCA became known as the “Deming Wheel.” Deming developed DMAIC to guide quality projects of existing business processes in a continuous effort to reduce defects.
Six Sigma is based on the continuous cycle of identifying and eliminating all sources of variation in process performance that significantly influence cost and quality. Therefore DMAIC was quickly recognized as a means of achieving the goals of Six Sigma projects. So harmonious are the five steps of DMAIC with project goals, it is now one of the two key methods on which Six Sigma projects are based.
In Six Sigma, DMAIC is basically a system for improving existing processes that perform or provide output below specifications by identifying solutions based on the collection and analysis of relevant data, and sustaining the improved process by measuring and monitoring its performance.
The following information describe the five steps of DMAIC when used in Six Sigma projects:
Define—Define the problem or the opportunity for improvement.
The problem should be clearly established in quantitative terms. All sources of variation, not just the current cause, must be specifically defined so that Six Sigma projects, improvement processes, and the goals relate to the true root causes of the problem.
Measure—Measure the process performance.
Collect data and take a base measurement to which future measurements can be compared and used to determine the factors that have influence concerning the outcome of the process or procedure.
Analyze—Analyze the collected data.
Use statistical tools to find the root causes of the problem and determine if the problem is solvable or random, and whether the process can be improved or should be redesigned.
Improve—Improve the process.
Provide solutions based on data analysis using techniques like design of experiments.
Control—Control the improved process.
Use data collection and control mechanisms so that any deviations from the target are apparent and corrected before causing defects.
Sources:
www.wisegeek.com/what-is-dmaic.htm
The Six Sigma Fieldbook: How DuPont Successfully Implemented the Six Sigma Breakthrough Management Strategy , by Mikel Harry, Ph.D., and Don R. Linsenmann (Currency Doubleday, 2006)
Links:
[1] http://elsmar.com/
[2] http://www.tech-faq.com/dmaic.shtml
[3] http://www.wisegeek.com/what-is-dmaic.htm