DMAIC in Six Sigma: 5 Steps Process

With technology continuously gaining its place in business landscapes, the fierce competition for the bottom line has become even stronger. Organizations try to be more efficient. The five steps of DMAIC in Six Sigma methodology can be used to improve any process performance within an organization, from manufacturing to customer service.

It focuses on customer satisfaction and improving product or service quality. It is a good reason why more businesses are adopting the DMAIC, a key process in building Six Sigma methodology-based improvement projects.

Improving existing processes that are not currently meeting customer requirements or producing defective products or services is the key focus. It can also be used to improve processes that work well but could be made even better. The methodology can also be used to develop new processes or to redesign existing processes.

DMAIC is an abbreviation for Define, Measure, Analyze, Improve, and Control. It is a data-driven improvement process that helps organizations achieve sustainable improvements in quality and performance. The five DMAIC process steps that must be completed in order are:

1. Define the problem and identify the opportunity.
2. Measure key aspects of the current process.
3. Analyze data to uncover the root causes of variation.
4. Improve the process by implementing solutions.
5. Control the process to ensure that the improvements are sustainable long-term.

In each phase, work is completed to ensure that the process meets the requirements for that phase. The process is completed when the project realizes the defined, measurable improvement, and the process is deemed to be stable and capable of meeting customer requirements.

When used correctly, it will take an existing process and improve upon a particular metric while reducing process variation. The metric could be anything from cycle time to defects per unit.

While DMAIC may seem like a lot of steps, each one is essential to ensuring the success of the overall process improvement project. By completing each step thoroughly, businesses can be confident that they are making positive changes that will have a lasting impact.

DMAIC in Six Sigma Methodology and Phases

Lean Six Sigma projects are an essential part of business process improvements today. They can generate breakthrough performance, so should not be treated as just another improvement initiative.

Every Lean Six Sigma project follows a standardized and systematic method, including these five distinct stages. This problem-solving procedure improves any type of process in any organization by improving efficiency and effectiveness.

The ‘Define’ phase

In the first phase of the Six Sigma DMAIC methodology, Define, and you define the problem. Here, you identify why you’re doing this project and the parameters you’re going to measure it with CTQ (Critical to Quality). This is an important phase because it sets the foundation for the rest of the project.

Objectives

The key objectives of the defined stage are:

• Putting together a process improvement team of competent people who will work together to understand the pitfalls and benefits of the proposed project plan.
• Outlining the project’s scope, goal, and objectives, its team members and sponsors, and its schedule.
• Determining the stakeholders, inputs, outputs, and the process.

Deliverables

The main deliverables for the Define phase:

1. Project charter – This explains why the project is necessary.
2. SIPOC analysis – Team members can use this analysis to get a feel for all the stakeholders and their relationships. The acronym SIPOC stands for Suppliers-Inputs-Processes-Outputs-Customers.
3. Voice of the Customer analysis – The VoC analysis provides team members with data about each stakeholder group’s needs and wants.
4. Definition of the CTQ and initial draft of the project objective

 By the end of the Define phase, the project team conducts a review with the Project Champion and Process Owner. It’s a chance to look over what the team learned in the Define phase and decide whether to move forward or not based on the clarifying understanding of the problem.

Suppose their original problem is still a significant enough problem. In that case, the Project Champion, Process Owner, and Black Belt or Master Black Belt will decide to move forward. In that case, the team heads to the Measure phase. Otherwise, the project is terminated.

The ‘Measure’ phase

Having completed the Define phase, we now have a good sense of our CTQ(s). The goal of the Measure phase is for the team members to understand the definition, measurement system, and current capabilities of each CTQ. In order to improve them in the future, it is essential to understand each CTQ and its behaviours. 

Objectives

The objectives of the Measure stage are:

• Defining processes in detail and understanding the decision points and functions of the process.
• Defining metrics to verify the process.
• Analyzing the measurement systems to identify any errors.
• Estimating the baseline for the project.

Deliverables

For the Measure phase, below are the main deliverables:

1. Operational definition of the CTQ(s) – Creating an operational definition for each CTQ ensures everyone is on the same page.
2. Data collection plan for the CTQ(s) – Creating a data collection plan to define what you are going to measure, how you will measure it, and who will measure it.
3. Measurement system validation for the CTQ(s) – Analyzing the measurement system to determine if it can deliver accurate data
4. Baseline data for each CTQ – Collecting baseline data to test each CTQ’s stability and capability.
5. Process capability estimates for each CTQ(s) – Comparing the output distribution of a process to the customer’s specification.

At this stage, you can collect data to see how well the process is performing. In other words, you can check your CTQ’s current state. By doing this, you can compare the performance of the current process to the improved one in the future.

Once this phase is over, the project team conducts another review with the Process Owner and the Project Champion to decide whether they should continue with the project. This is where the project team reviews what they learned so far and looks at the baseline data collected.

If the reevaluation confirms the significance of the problem, the team proceeds to the Analyze phase. If not, the project is scrapped or sent back to do the Measure phase again.

The ‘Analyze’ phase

In Analyze, the third phase, you will use the data you collected in the previous phase to identify the root causes of the problem. The goal here is to determine which process parameters have the most impact on the critical process outcome. This is a crucial step because it will help you focus your improvement efforts.

Objectives

The main objectives of the defined stage are:

• Analyzing the value stream
• Analyzing the sources of variation
• Identifying the vital few process drivers that have the biggest influence on the process output and stakeholder requirements

Deliverables

Analyze phase deliverables include the following:

1. Detailed flowchart of the process – Creating a current state value stream map to identify the process steps that produce value for the customer and their current performance.
2. Identification of potential factors creating issues for each CTQ – This can be accomplished by analyzing the current state, talking to process experts, reviewing the literature, etc.
3. Failure Modes and Effects Analysis (FMEA) – FMEA is used to reduce the number of potential factors by identifying the most critical ones that reduce variation, improve efficiency, or eliminate waste.
4. Operational definitions of factors – During this phase, the operational definitions to be developed for each factor are similar to the definitions of the operations developed for each CTQ during the last phase.
5. Data collection plans were developed for each factor.
6. Validated measurement systems for each of the factors.
7. Data collected, and theories tested to identify how and why each factor causes issues with the CTQ.
8. Established hypotheses about the relationships between the critical factors and the CTQs.

At the end of the Analyze phase, the project team conducts a third review with the Project Champion, Black Belt, and Process Owner to decide the continuity of the project. The team reviews what they have learned in the Analyze phase, and based on the overall performance, the team proceeds to the Improve phase.

The ‘Improve’ Phase

You implement solutions during the Improve phase. This is where the team starts implementing the changes needed for process improvement based on what they learned from Analyze phase. In order to achieve project goals, you need to find the best opportunities for improvement that minimize the types and sources of variation.

You can test the proposed methods with a pilot run. A pilot reduces failure risks and can provide a better forecast for future project savings. It also facilitates smooth transitions and cross-functional collaboration for the actual implementation stage. It helps management monitor the progress of the project.

Objectives

The key objectives of the Improve phase are:

• Determining new process operating conditions.
• Investigating failure modes for the new process.
• Estimating the benefits associated with the proposed solution.
• Implementing and verifying process improvements.

Deliverables

The following are the main deliverables for the Improve phase:

1. Pool of alternate solutions to improve the mean, variation, and shape of the CTQs – Generating these can be done through FMEA, brainstorming, simulation, or benchmarking. 
2. Best alternative solution selected for implementation 
3. Flowchart for the new optimized process.
4. New process risks identified and mitigated.
5. A pilot run of the new, improved process.
6. Data analysis for the pilot run.
7. Full-scale implementation across the organization.

To review what has been learned during the pilot test, the team conducts a review with the Project Champion, Process Owner, and Black Belt at the end of the Improve phase.

Suppose the comparison of pilot test data to the baseline data reveals an improved performance level of the CTQ. In that case, the project is moved to the next phase, Control, to implement measures to sustain the improvements.

Otherwise, the project returns to the Analyze phase to find another set of factors that can improve the distributions of the CTQs.

The ‘Control’ phase

The final phase ensures that improvements are working as intended and integrated into the organizational culture. The optimized settings of the critical factors must be fixed, and they should be insensitive to human and environmental noise to get the best results.

Continuous monitoring of the process and collecting data can ensure that the problem does not occur again. The Control phase can also help quantify the process change in terms of total cost reduction, efficiency improvement, and customer satisfaction.

Once this phase is completed, the improved process is handed over to the Process Owner so the PDSA cycle can be continued. 

Objectives

Below are the main objectives of the Control phase:

• Standardizing the process to include the newly added practices and methods.
• Verifying the impacts of the improvements, including financial returns.
• Documenting the lessons learned.

Deliverables

Control phase deliverables are:

1. Unintended impacts on related processes are minimized.
2. Improvements are standardized to the process.
3. Control plan for the Process Owner.
4. Benefits and costs document of the project.
5. The implemented solution is shared in the Six Sigma database.  
6. Improvements spread across the organization.
7. Champion, Process Owner, and Black Belt sign-off on the project.

After the Control phase, the team conducts a final review with the Project Champion, Process Owner, and Black Belt. At this point, the team reviews the lessons learned.  Finally,  the project is closed,  the project team is disbanded, and everyone celebrates their success.

The key to changing an organization’s culture to a process-oriented culture is to keep improving processes.

Resources and further readings

• A Guide to Six Sigma and Process Improvement for Practitioners and Students: Foundations, DMAIC, Tools, Cases, and Certification, Second Edition by Howard S. Gitlow, Richard Melnyck, David M. Levine
• Six Sigma Demystified, Second Edition, 2nd Edition by Paul Keller