Six Sigma is an improvement methodology, generally credited to Dr. Mikel Harry while at Motorola. The basic premise of Six Sigma is built on the old adage, “If you can’t measure it, you can’t manage it.” Originally applied to manufacturing/product improvement, once embraced by GE it was successfully applied to services. My experience at GE, and my focus here, will not be on improving the ubiquitous widget (i.e., tweaking raw materials, production machinery, and measuring devices). Rather, I will focus on service processes – performed by people who process information, make judgments, and count things.
A Six Sigma approach to process improvement follows the traditional Define, Measure, Analyze, Improve, Control (DMAIC) roadmap.
§ In the Define phase you make the business case for the project and specify the boundaries of the process to be improved.
§ In the Measure phase you specify the process output characteristic(s) of interest, define how the characteristic(s) will be measured, plan the data collection, and collect data.
§ In the Analyze phase, you quantify the current state of the process and identify potential sources of process variation.
§ In the Improve phase, you plan and execute experiments to confirm the sources of variation, and to develop process improvements to eliminate the variation.
§ In the Control phase, you quantify the improved state of the process and develop process controls to maintain and further the improvements.
More recently Lean Six Sigma has been widely adopted, combining the concepts and tools of the Toyota Production System with Six Sigma. From my perspective, the basic DMAIC roadmap does not change with the integration of lean, the toolbox simply gets bigger and better!