Why We Use DMAIC For Process Improvement

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Why We Use DMAIC For Process Improvement

DMAIC - The 5 Steps

Why do we use DMAIC? It’s a valid question we ask when learning Lean Six Sigma. In short, we use DMAIC because it is an ordered, data driven approach to reliably identify issues and implement meaningful improvements. To truly understand why we use DMAIC, let us explore what DMAIC really is – a toolkit to solve complex problems with no clear solution. There are 5 steps to DMAIC: Define, Measure, Analyze, Improve, Control, with each phase marked with a Gate review. This is a stop-gate at the end of every phase where we determine if we have sufficiently performed the phase and can move on to the next one.

DMAIC - The 5 Steps

Step 1 - Define

In the Define phase, we lay the foundation of our project. This phase is focused on framing the problem, goals, and resources of our project. We begin by understanding the problem and how it is impacting our business. We must state the problem clearly, and gather as much evidence as we can to clearly state our problem. In this phase we also identify our stakeholders, subject matter experts, and process owners to form our core team. Then we build our SMART (Specific, measurable, attainable, reasonable, time-bound) goal statement, business case, and project charter to guide us along this journey of improvement. Once we have our resources, owners, core team, and project charter- we present them to our key stakeholders in the Define gate review. In the Define gate review- approval means we have made a strong case for our project and have approval to move on to the Measure phase.

Step 2 - Measure

In the Measure Phase we begin measuring our baseline and process stability. This allows us to more deeply understand our problem and the data that constitutes it. In this phase we should look at our key process indicators, the data collection methods, and the underlying assumptions to all of these to ensure two things: that they are being gathered accurately and that they are the most relevant measures we have to quantify our baseline and eventually gauge our improvements. Once we have validated our data and assumptions, we can go through the Measure gate review into the analyze phase.

Step 3 - Analyze

In the Analyze phase we take the validated data and processes from our previous phases and dig into the root cause of our problem. We use a variety of tools and analysis to identify the root cause of our issues. We do this through three primary methods: graphical data analysis (e.g. run charts, pareto diagrams, etc.), examining the process (value stream mapping, time analysis, 8 waste analysis, etc.), and deep diving into the root causes (fish bone diagrams, guided brainstorming, 5 why, etc.). Meaningful improvement comes from understanding and treating these root causes instead of merely fighting fires and treating symptoms. Once we have agreed upon our root causes we go through the Analyze gate review onto the Improve phase.

Step 4 - Improve

In the Improve phase we can confidently build upon the root causes identifies in the Analyze phase to create and implement countermeasures. We do this by using tools to brainstorm solutions and prioritize them by assessing risk, cost, and impact. Weighted priority matrices are a great way to prioritize solutions with many variables in mind such as cost to implement, ease of implementation, and impact. To be process maps are used to visualize the new processes we implement and can be used for training new employees in the process going forward. Then, armed with the measurement plan and assumptions we made in the Measure phase, we validate the improvements after we implement them and confirm the impact using statistical analysis. These results will be presented in the Improve gate review.

Step 5 - Control

Now that we have passed our gate review, we need to make sure these improvements stick. Enter: the Control phase. In this phase we implement process controls such as control charts to monitor our new processes and ensure our improvements made in the Improve phase keep long term. As well, we document our new process for reference in the future. Finally, we take stock of the lessons learned from this process and how they can be applied to future projects. This is the most important step in the DMAIC process. Without this step, all of the previous steps are frankly a waste of time. This step is critical in ensuring long term success, particularly if you are acting in a consulting capacity and need your improvements to stay after you have left. After we demonstrate our control plan in the Control gate review, we can celebrate a job well done!


Now that we understand the DMAIC process, we can understand where to use it and why. When we encounter complex problems with no clear solution, this provides a structured, data driven approach to understanding our problem and creating sustainable countermeasures that will last. When using DMAIC, we can be sure that we are driving meaningful, long lasting change that we can clearly quantify, control, and continuously improve. That is why we use DMAIC.

-Joel Chapa, Consultant Lean Sigma Pros LLC

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