Tools of DMAIC

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Insha Rafiq

In this article you will get an idea of tools of DMAIC. DMAIC is an approach used in improvement projects particularly, six sigma. We will discuss tools of DMAIC by phase. Most times these tools are also called tools of six sigma. Purpose of each tool is also discussed.

We have listed around 40 tools and its uses for DMAIC in this article. Read on….

In1986 an American engineer Bill Smith introduced Six Sigma while working for Motorola. Six Sigma is a set of tools and techniques designed in order to improve business by reducing the chance of error. Six Sigma aims to improve quality by finding defects, determining their cause, and improving processes by reducing errors and increasing accuracy of process results.

Stages of DMAIC

DMAIC, set of few steps also known as methodologies of Six Sigma which helps in improving existing processes. It is the most common method associated with Six Sigma. Lets now study about steps and tools of DMAIC in detail.

Five phases of DMAIC.

Define.
Measure.
Analyze.
Improve.
Control.

Tools used in the Define phase

Define phase: In this phase, we will create the outline of the project which includes what is the problem, why should we find a solution to this problem, a timeline of the project, expected benefits, expected implementation cost and who all to be included in this project, etc.

This is problem defining stage. Problems are identified which causes negative impact on the processes and needs to be corrected.

Various tools and their uses are listed in the below table.

Tools used	Use
Business Case	This will properly communicate the purpose of improvement project. Particularly why this project? or what all benefits will we get after completing this project.
Project charter	The project charter (written document that records and summarizes the elements of the project) is developed to communicate overall summary of the project including project description, goal of the project, team members and schedules and targets.
SIPOC	SIPOC is diagram which communicates the information about the Suppliers, Input, Process, Outputs and Customers of a process. Hence we will have more data for arriving the solutions and chances of missing a solution or cause will be less.
VOC	Voice of Customer (VOC) represents the feedback or expectations or needs of customer about your product or services.
CTQ identification	Critical to Quality (CTQ) are the various factors of the output of the service or products which affects the satisfaction of the customer. CTQ is derived from VOC. For example: On time delivery of the courier service. In this example on time delivery is a CTQ.
CTQ specification table	This table lists all CTQs and its specification. For example delivery to be made within 1 minute tolerance from the committed time.

Tools of Define phase of DMAIC

Tools used in the Measure phase

Measure : In this step extent of issue or simply we can say magnitude of problem is measured. In other words, we can say that this a data collection step. We measure CTQs identified in the define phase.

There are various tools we use in measure phase. Lets have a look at few of them.

Tools used	Uses
Funneling	Determine the critical few measures from the measure phase.
Data collection plan	It is simply data collection step and deals with different questions like data type, mode of measurement, related conditions, sampling notes and how data will be displayed.
Gage R&R	Table which shows different measurements carried in different trails and helps to validate our measurement system.
Data Display	Data collected is represented in histogram which allows us to see the frequency distribution of a data set. In short we can say it helps us to visualize what is going on.
Project mapping	Results are compared with the baseline status of CTQs by using average, PPM and sigma level, here actually we calculate current process capability and sigma.
Baseline status of CTQ	Calculates current process capability.

Tools of Measure phase of DMAIC

Tools used in the Analyze phase

Analyze : Analyzing the root cause of the problem is main purpose of this step. To summarize this step, root cause of problem is defined and analyzed.

In other words, we use the data obtained in the measure phase to identify the root causes that we want to fix.

Let’s have a look at few tools used in analyze step.

Tools used	Use
Flow Chart	For better understanding of the process diagrammatically.
Value added and non-value added analysis	Helps to identify value added steps as well as non value added steps of process
FMEA	Helps to identify potential causes of a problem.
Cause and effect diagram	Helps to visualize, sort and list all possible causes of a problem.
Brainstorming	Helps to generate all possible causes of a problem.
Scatter diagram	Using this we can identify relation between two variables.
Histogram	Variation in a data set can be studied.
Pareto Chart	Visualizes top causes contributing to a problem.
Hypothesis testing	Using this we can use accurate decisions based on data.
Regression analysis	Analyses root cause of defects by examining the relationship between various variables.
Design of Experiments	Helps to arrive optimum values of Xs to get result (Y). For example in preparation of tea, cooking time, sugar and milk quantities are Xs and Taste of tea is result (Y). In DOE what we do is do experiment with different values of X to get good result.
Box plot	Helps to understand the variation in a data set.
Why why analysis	Using this we can arrive the root cause of a problem.
Pareto charts	A type of bar chart which shows frequency of each defect that occurs in descending order of magnitude as in this chart x axis is splitted to represent different defects.It is a powerful tool used to attack buk of problems with optimal utilization of resources.
Frequency plot	A frequency plot creates a picture of variation in a process that helps to provide clues to certain types of problems so that it can verify whether data are distributed normally or not.
Critical causes table	Shows causes which affect CTQ
Cause validation plan	This helps to validate the effect of cause to the problem

Tools of Analyze phase of DMAIC

Tools used in the Improve phase

Improve : Improve phase is the fourth phase of DMAIC. The main activity in the Improve phase is to determine the best solution for the problems identified in the first three phases.

In this phase, project teams focus on eliminating the root causes by using different tools like brainstorming sessions ,so that we can get a set of possible solutions to the problem already defined in previous phase.

Among obtained set of different possible solutions from team members, we select the best one solution which is eliminating root cause of our problem.

After this we test the best possible solution on a small scale like in a pilot mode.

If the expected project goals are met then we carry on with this solution, otherwise we choose other solution till we achieve our goal.

Tools used	Uses
Cost-Benefit Analysis	This tool enables to do cost-benefit analysis for the preferred solution.
Brainstorming	For arriving solutions
Solution prioritization matrix	Best solution is selected based on different criteria such as cost, implementation time, easiness, etc.
Piloting	On a small scale project is made to run to check effectiveness of the solutions, to reduce the risk of failure in large scale.
FMEA	Failure Modes and Effects Analysis (FMEA) of improved process is done to identify risks associated with solution and helps us to take preventive actions.
Implementation planning	A detailed plan to implement the selected solution.

Tools of Improve phase of DMAIC

Tools used in the Control phase

Control : Fifth and last phase of a DMAIC is Control. In the Control phase we deal with controlling the improved process by using different tools.

Tools used	Use
Control charts	A special type of graph which helps to study how our process changes with respect to time after implementing the best solution.
Pareto charts	Here new pareto charts are prepared by using same scale and dimensions so that we can easily analyze degree of improvement.
Documentation and Standardization	Using training manuals and other tools new documentation is done to ensure standardization.
Monitoring	Using control charts process is monitored to ensure process remains in control.
Evaluating results	Here process capability, process sigma and financial results are recalculated based on the improvements that were done.
Key learnings	Summary of key points, results is done.
Closure	Closure of project by a good presentation and here again the search for identification of potential future projects begins.

Tools of Control phase of DMAIC

About the author

Insha Rafiq is a spirited and motivated learner with strong work ethic, creative ability and dedication. She is from Srinagar, Kashmir and a mechanical engineering graduate of SSM College of Engineering and technology. She is interested in writing and learning about new and emerging fields of science & technology particularly related to industrial engineering domain.

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