Lean Six Sigma is a broad body of knowledge. The backbone of this continuous improvement approach is the D M A I C (Define Measure Analyze Improve Control) problem-solving methodology. Lean practitioners often prefer to use P D C A (Plan Do Check Act) as their problem-solving methodology. If one is interested in a single problem-solving methodology and would like to integrate Lean and Six Sigma, how does one use the D M A I C methodology to solve Lean problems?
First, it is essential to engage the individuals who are working within the process. Lean is a bottom-up approach that leverages a high level of engagement. This engagement leads to robust improvement ideas and ownership of the identified solutions. A Lean DMAIC project should be done with a team of individuals who work within the process. Before starting the project, establish the work charter with the project owner and leader and identify the team members, resources required, and timeline for the project.
Define. In the Define phase, it is necessary to have a clear problem statement. This is normally defined in the work charter but may be refined through the define and measure phases. Typically, a Lean project will have a time-based objective to improve. It could be that one would want to reduce process time, cycle time, or eliminate waste from a process. It is also necessary to measure the current state of the process and determine if the process is operating as a normal distribution. In the define phase, there is a need for a clear “Voice of the Customer.” Often there is an internal customer for the process, but the most effective way to capture the real value of the process is to ask an external customer for their perspective. Are they willing to pay for the various elements of this process? Finally, it is necessary to define the process being studied using a simple SIPOC (suppliers, inputs, process, outputs, and customers).
Measure. The Measure phase is the pivotal for process improvement. The key to a successful measure phase is the use of the Value-Stream map to define and measure the process. Each element in the process must be defined and measured. One must then determine, using the voice of the customer, whether an element is value-added or non-value added. A calculation of the % value-add is done. Often the problem statement is revised based upon what is learned through the Value-Stream map. During the measure phase, waste hunting is also performed. There can be overlap between the non-value-added elements and identified waste, but usually the waste identified is more granular than the elements outlined in the Value-Stream map.
Analysis. Due to limited resources, it is not possible to eliminate or reduce all the non-value added steps and/or waste. In the Analysis phase, the opportunities for improvement need to be prioritized. This can be done in many ways but one of the most common methods is to use a 2 x 2 matrix prioritizing the value gained and the ease of implementation to drive the priorities. Avoid choosing actions that require significant engineering or investment. These types of improvements typically slow down the project. Choose enough improvements to achieve the process improvement objectives. For each element selected for improvement, conduct root-cause analysis to determine why this non-value-added element or waste exists. Getting to the root cause will help to ensure that the actions taken to improve the process will be sustained after the control phase.
Improve. In the Improve phase, actions are chosen based upon the root cause analyses and launched. Set deadlines and track progress on each of the actions on a regular basis. As improvements are made, stabilize the revised process and measure results. It is not uncommon to make ongoing adjustments to the chosen solutions to achieve the full potential of the process improvement.
Control. Significant process improvements from the use of the DMAIC process are often lost because of poor implementation of the final phase: the control phase. Strong controls must be put in place. Automatic controls are best. Automatic controls prevent changes or mistakes from being made in the process. They do not rely on a person to ensure the improved process runs correctly. Where automatic controls are not possible and people must be relied upon to sustain the improvement, it is best to make controls visual. Visual controls are easy to understand and easier to follow than written controls. Written controls are the least preferred choice to control the process and in the absence of automatic or visual control options, can be used. As part of the Control phase, it is also essential to identify who will own the process improvements and continue to measure the process to ensure the effectiveness of the implemented improvements.
Lean problems can be resolved using the Six Sigma DMAIC methodology. This methodology will drive significant process improvement. Keys to success include ensuring there are time-based process improvement objectives and engaging individuals who work within the process. One must also ensure robust controls create sustained business results.
About the Author: Mike Ungar is a Certified FocalPoint Business Coach and Trainer. He has 35 years of experience with Michelin in manufacturing and human resources. Mike is a graduate of the United States Military Academy at West Point and the Clemson MBA program.