DMAIC Method in Six Sigma | 5 Phases | Complete Overview

What is the DMAIC approach in Six Sigma?

→ DMAIC stands for its five steps – Define, Measure, Analyze, Improve, and Control.
→ It is a structured methodology and it helps in achieving improvements by reducing variation.
→ It is a data-driven approach for improvement.
→ This Methodology is used for improving, optimizing, and stabilizing business processes.

What is the Concept of Six Sigma Project?

→ 6𝞼 refers below concepts.
→ Y is the outcome that you desire from a process.
→ Y is a dependent factor and it depends on the X’s.
→ X represents the input factors that affect the result of the process.
→ There could be multiple X’s.
→ Ɛ represents the presence of error, or uncertainty surrounding how accurately the X’s are transformed to create the outcome.
→ In other words, the input variable(X) is transformed by a function (or processes) and combined with error to form the output.
→ The Y is a result or outcome or we can say Y is a function of X's.
→ To determine the desired outcome, you apply a transformation process (or function (f)) on input.

➨ We will understand the above concept with the help of the below example,
→ We all know that the pizza should be delivered within 30 minutes.
→ That is our Y or final outcome. (the delivery time is our Y)
→ There are several factors affecting pizza delivery from the pizza shop to the customer's home.
→ We assume that the pizza was not delivered within 30 minutes.
→ There may be many possible reasons like, due to heavy traffic, the driver did not know the address, pizza was not prepared in time, the bike was punctured, the bike fuel was empty, and many other reasons.
→ The reasons for not delivering the pizza on-time are “X’s”.
→ And the Ɛ can be the varying time of each activity throughout the delivery (or errors in the processes).
→ After understanding this example, in order to get a result, should we focus on “Y” or “X”?

Where we have to focus during the Six Sigma project?

→ Whenever we do a 6𝝈 project, the focus of the team needs to be on identifying the causes (i.e. focus on "X") and mitigating them.
→ The result (i.e. "Y') will automatically be improved if the causes (i.e. "X") are eliminated properly.
→ In the above example, the reason for late delivery is the causes and the delivery on time is the final outcome or result.
→ So the "X's" (i.e. the causes) are due to heavy traffic, the driver did not know the address, pizza was not prepared in time, the bike was punctured, the bike fuel was empty, and many other reasons.
→ Thus, focus on the Causes (X) and the result (Y) will automatically be improved.

Characteristics for Successful Six Sigma Projects:

→ The projects should be related to your day to day work.
→ It should be manageable in terms of time-frame.
→ It should be aligned with business goals, objectives, and also address only one CTQ (Critical To Quality) parameter at a time.
→ Also, It should address issues that are important to the customer.
→ The improvements that you do should be locally actionable
→ In the above characteristics, we have a CTQ parameter.
→ Here, CTQ stands for Critical To Quality.
→ In easy language, CTQ is nothing but a metric that helps in measuring the extent of performance.
→ CTQ can be of various types such as CTD (Critical to Delivery), CTP (Critical to Process), and others.
→ Some of the examples of CTQ’s are cycle time, quality scores, Yield%, etc.
→ The scope of the 6𝞼 projects must be defined and limit the boundary it must not solve the issues like global warming or the world’s pollution.

What are the 5 steps of the Six Sigma improvement model?

1. Define,
2. Measure,
3. Analyze,
4. Improve and
5. Control

Define phase in DMAIC:

→ The purpose of the Define stage is to clearly define the business problem or goal and many more things depending on the project.
→ Also, keep a record of all details in the project charter.

➨ Activities in Define stage
→ Develop a problem statement
→ Define the goal statement
→ Record or note down the voice of the customer (VOC) and translate the VOCs into CTQs (Critical to Quality) requirements.
→ Identify the benefits expected through the completion of the project (Business Case)
→ Define the Scope of the projects and identify resources
→ Identify the champion, subject matter expert, and team members
→ Develop a Plan
→ Develop a High-Level Process Map - 3 Methods for as-is mapping
     (1) SIPOC Diagram
     (2) Value Stream Mapping (VSM Study)
     (3) Process Flow Diagram (Flow Chart)

Measure phase in DMAIC:

→ The purpose of the Measure step in 6𝞼 is to create a complete picture of the current process state and establish current baselines.
→ To identify the baseline sigma level.
→ Use this baseline for setting the target as an improvement.


➨ Activities of the Measure phase
→ Prepare detailed process maps with including long or incorrect cycle times, bottlenecks or non-value added steps.
→ Also, identify where data has to be collected.
→ Develop Data Collection Plan
→ Validate the Measurement System
→ MSA and GRR Study can help for validating the measurement system
→ Collect the Data and the Control Chart can help identify any trends or outlying measurements.

Analyze phase in DMAIC:

→ The purpose of this stage is to identify all possible causes and then find out the root cause or causes.

➨ Activities of the Analyze phase
→ Analyze the Data
→ The data analyzing method is depending on the type of data collected.
→ Identify Causal Factors
→ Find out a valid root cause or causes by brainstorming.
→ The Fishbone Diagram (Cause & Effect Diagram)  is also used to find out the root cause.
→ Another popular and effective method for root cause determining is 5 Why method
→ Scatter Diagram is also used for validation activity

Improve phase in DMAIC:

→ In this step, the 6𝞼 project team should identify, implement, and validate corrective actions to resolve any issues.


➨ Activities of the Improve phase
→ Identify Potential Solutions
→ Analyze the cost-benefit analysis of the implementation of the solution.
→ By Brainstorming, the team should identify possible improvements that would increase efficiency and improve product quality.
→ Analyze Failure Modes of Proposed Solutions
→ Failure Modes and Effects Analysis (FMEA) is often completed before the implementation of any changes.
→ The FMEA helps the team identify and address potential failure modes that may arise due to the improvements in the system or in the operation sequence.
→ Validate Improvements
→ Validation may be tested on prototype builds or on simulations.
→ Estimate the financial gains.
→ Validate the updated operation flow.
→ Develop a Risk Mitigation Plan and Process Control Plan.
→ Implement the solution as per planning

Control phase-in DMAIC

→ In this step, the team checks the sustainability of the changes were made during the project.
→ Also, the team ensures the sustenance of implemented improvement.

➨ Activities of the Control phase
→ Update Documentation like Standard operating procedures (SOP's), Control plan, Development plans, Process Maps, Work Instructions, Visual Aids, etc.
→ Give training to all associate about the changes were made during the project.
→ Communicate about the updated roles and responsibilities.
→ Implement Statistical Process Control (SPC)
→ Create a Process Monitoring Plan
→ Celebrate the successful completion of the project with the team and top management.
→ Ensure an ongoing Process Monitoring Study is working properly.
→ Communicate to Business Results & sign off to close the Six Sigma Project

👉 See Also:

➨ All Topics

➨ ISO 9001:2015

➨ 7 QC Tools

➨ Quality Core Tools like MSA, FMEA, APQP, SPC

➨ Six Sigma

➨ QA & QC Topics