Six Sigma Part 2: DMAIC Methodology

DMAIC is an acronym for define, measure, analyse, improve and control. It focusses on the improvement of existing process in industry to minimize the junk.

D: Define the goal of the project and customer deliverables (both external and internal).

M: Measure the process to check the current performance and quantify the problem with data.

A: Deeply analyse the root cause of the defect in the process.

I: Improve the process by eliminating all the defects.

C: Control the process after the defect elimination for future working.

The detailed step in each process of DMAIC are as follows (from simplilearn):

[1]. Define:

Step 1: The business problem is defined from the customer perspective.

Step 2: Goals are set. What do you want to achieve? What are the resources you will use to achieve the goals?

Step 3: Map the process. Verify with the stakeholders that you are on the right track.

 

[2] Measure:

Step 1: Measure your problem in numbers or with supporting data.

Step 2: Define performance yardstick. Fix the limits for "Y."

Step 3: Evaluate the measurement system to be used. Can it help you achieve your outcome?

 

[3] Analyse:

Step 1: Determine if your process is efficient and effective. Does the process help achieve what you need?

Step 2: Quantify your goals in numbers.  For instance, reduce defective goods by 20%.

Step 3: Identify variations using historical data.

 

[4] Improve:

Step 1:  Identify possible reasons. Test to identify which of the "X" variables identified in Process influence "Y."

Step 2: Discover relationships between the variables.

Step 3: Establish process tolerance, defined as the precise values that certain variables can have, and still fall within acceptable boundaries, for instance, the quality of any given product. Which boundaries need X to hold Y within specifications? What operating conditions can impact the outcome? Process tolerances can be achieved by using tools like robust optimization and validation set.

 

[5] Control:

Step 1: Validate the measurement system to be used.

Step 2: Establish process capability. Is the goal being met? For instance, will the goal of reducing defective goods by 20 percent be achieved?

Step 3: Once the previous step is satisfied, implement the process.