The Six Sigma procedure aims at definition, measurement, analysis, improvement, and control of the required manufacturing or business process. Read on for an overview of this core Six Sigma DMAIC methodology.
Six is a business management strategy for organizations to improve their manufacturing or business processes by identification and removal of defects or errors, and ensuring standardization by minimizing variability.
The core of Six Sigma procedure lies in five steps: DMAIC (Define, Measure, Analyze, Improve, and Control) or DMADV (Define, Measure, Analyze, Design, and Verify). The former finds application to improve existing business process and the latter finds use when creating new product or process designs.
D = Define
The Six Sigma procedure aims at definition or articulation of the problem or process that requires change in specific terms, such as the customer’s concern, or the desired project goals. A project team created to see through the procedure creates SIPOC, a diagram to identify the examined process, inputs, outputs, and the relevant suppliers and customers, and collects data from the identified customers to find out the optimal desired quality.
To cite an example, the pre-Six Sigma vision of an organization might be “to increase profits by boosting productivity." The first step of the Six Sigma procedure is to articulate this vision in specific terms. Application of the Six Sigma procedure leads to a more specific objective, such as “to increase profits by a change in the work pattern, work flow, or work design aimed at boosting productivity."
M = Measure
The second step in Six Sigma procedure is to “Measure" or quantify the problem articulated in the first step. The quantification takes place in two steps
- drawing up a process map that help identify characteristics critical to quality, production capabilities, and risk factors
- collecting relevant data from the identified key characteristics.
An organization planning to boost productivity by ensuring change in the work pattern, workflow or work design might identify the key characteristic that influences productivity as the worker’s output. Application of Six Sigma tools in this example might, for instance quantify the problem as “to increase production per worker by “x" units a day by cutting down on the time the worker processes a unit from 90 seconds to 75 seconds.
A = Analysis
Analysis of data entails investigation and verification of all possible cause-and-effect relationships pertaining to the problem. For new projects, analysis of data requires creating alternative designs and selecting the best design from the available options. The major tool used at this stage is Statistical Analysis.
In the example referred above to increase productivity, analysis of data could identify the one possible factor that influence the time a worker spends to manufacture or process one unit, as slack due to monotonous work. Application of Six Sigma Tools might suggest giving frequent short breaks instead of one long break during a shift as a measure to reduce slack.
I = Improve
The “Improve" phase of Six Sigma procedure entails optimizing the current or newly established process by using brainstorming, design of experiments, mistake proofing, and various other available techniques. Analysis of the data obtained during the "measure" stage, after the application of the optimized or improved process tracks the difference in output, and such analysis continues after every stage of improvement until the project team attains the desires levels of improvement.
The "Define," "Measure," and "Analyze" stages are common for all Six Sigma projects. The "Improve" stage remains relevant only for Six Sigma interventions on already existent and running projects. For new projects, with nothing to improve, the "Improve" stage becomes the “Design" stage where a pilot run of the newly established system aims at establishing process capability.
In the example referred in Page 1 to boost productivity, application of Six Sigma tools might indicate the optimized time of frequent short breaks as five minutes of break after every hour of work.
C = Control
The “Control" phase of Six Sigma procedure aims at preempting any deviations from the target to eliminate defects, and entails drafting steps to sustain the solution and prevent relapse to the original condition. For instance, in the above quoted example of improving productivity by offering workers frequent short breaks, Six Sigma procedure could effect a new control that stops work flowing into a workers desk after an hour of continuous work.
The successful adoption of sufficient controls indicates that the Six Sigma intervention is complete. The project team now hands over the modified process with controls to the project owners for day-to-day running.
The proper adoption of the Six Sigma roadmap is of critical importance for the success of the Six Sigma intervention, which in turn boosts process efficiency, reduces waste, enables taking informed decisions, and other benefits, leading to overall gains and improvements for the organization and its stakeholders.
- Westgard, James, O., PhD. Six Sigma: Quality Design and Control Processes. Retrieved from http://www.westgard.com/lesson67.htm on April 19, 2010
- Tennant, Geoff (2001). SIX SIGMA: SPC and TQM in Manufacturing and Services. Gower Publishing, Ltd. ISBN 0566083744.
- Motorola University: Retrieved frrom http://www.motorola.com/motorolauniversity on April 19, 2010.
- Page 1: Jayen466, Fleshgrinder: Wikimedia Commons
- Page 2: N Nayab