DMAIC: Lean Six Sigma Methodology for Continuous Improvement

Phase 3: Analyze

The Analyze phase aims to identify the root causes of the problems identified in the previous steps. It involves examining the data collected in depth to understand the factors causing failures in the process. A common method is the use of the Ishikawa (Fishbone) diagram , which allows you to categorize the different possible causes of a problem. The 5 Why’s is also used to delve deeper into each cause by asking successive questions in order to get to the root of the problem.

The goal of this phase is to focus efforts on the real causes of variations, rather than on the symptoms. This allows more effective corrective actions to be formulated. This in-depth analysis also allows better prioritization of actions to be taken to improve performance.

Examples of tools:

Ishikawa (Fishbone) Diagram : Visualizes possible causes of a problem.

5 Why’s : Technique to identify the root cause by asking five successive “Why” questions. Link to a 5 Why Excel template.

Phase 4: Improve

The Improve phase involves developing, testing, and implementing solutions to eliminate the root causes of the problems identified in the Analyze phase. At this stage, teams are encouraged to be creative while remaining realistic in their proposals. One of the main tools is the Countermeasure Matrix , which helps prioritize corrective actions based on their impact and feasibility. It is also important to conduct pilot tests to ensure that the solutions are effective before large-scale implementation.

Improvement must be measured throughout the process to ensure that the proposed solutions lead to tangible and sustainable results. This includes establishing an action plan detailing the specific steps, responsibilities and deadlines for implementing the solutions.

Examples of tools:

Countermeasure Matrix : Prioritizes actions to be taken.

Action Plan : Organizes the implementation of solutions, link to an Excel action plan template .

Phase 5: Control

The Control phase is essential to ensure that the improvements implemented are maintained over time. The goal is to prevent any regression to the old state of the process and to ensure performance stability. This step involves using tools such as Statistical Process Control (SPC) to monitor variations, as well as setting up a control plan that describes the actions needed to maintain the gains made.

5S and poka-yoke (error-proofing) methods can be implemented to make the process more robust and prevent errors from recurring. Regular monitoring is done to ensure that the process continues to operate according to the new standards established.

Examples of tools:

SPC (Statistical Process Control) : Allows monitoring of process variations.

Control Plan : Documents actions to maintain improvements.

Poka-yoke : Error-Proof Method to Avoid Human Errors

Conclusion

DMAIC is a powerful tool for improving processes and ensuring a structured approach to problem solving. By following the five phases – Define, Measure, Analyze, Improve and Control – companies can identify the root causes of malfunctions, implement effective solutions, and ensure that these improvements are sustainable. By implementing DMAIC, organizations are able to reduce defects , improve efficiency and achieve higher levels of performance , while meeting customer requirements and remaining competitive.

You can download a DMAIC tracking Excel template to track and manage your continuous improvement projects.