Six Sigma was a quality improvement method that was developed in the 1980s. This approach was made famous by Bill Smith, an engineer who worked at Motorola in the 1980s. It is now one of the most popular methods to improve business processes, product quality, customer satisfaction, and increase profitability. Although Six Sigma has seen many improvements over the years, the main goal remains to improve business processes by eliminating errors that lead to defects in products or services.

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This requires a combination of management philosophy, statistical tools, and problem-solving approaches to eradicate errors and create systems. Six Sigma practitioners have different levels of accomplishment: Six Sigma Yellow Belt CertificationGreen Belt CertificationBlack Belt Certification, and Master Black Belt.

Six Sigma was founded on the bell curve that Carl Frederick Grauss, a 19-year-old scientist, created. Cark Shewhart was a founding member of the Institute of Mathematical Statistics. He showed that the process had deviated by three sigmas from the mean and needed to be corrected. In the 1970s, Motorola's Senior Executive, Art Sundry, complained about a lack of consistent quality products. Bill Smith responded to the complaint in 1986 by implementing six-sigma. Other management improvement strategies, such as Total Quality Management and Zero Defects, also influenced the system over time.

This article will discuss the DMAIC framework, provide an overview of each phase, and offer tools to help you in each step.

DMAIC Framework

The DMAIC framework is a tool that can use to improve business processes. DMAIC, a five-step data-driven approach to improving manufacturing and business processes, is effective and efficient. It stands for Define. Measure. Analyze. Improve. And Control. this method is Created to deliver the highest possible performance without defects at competitive quality costs.


Let's talk about the five phases that make up DMAIC.


This is the first stage in which customers are identified, as well as internal and external deliverables. The goal of the project is also determined. This phase focuses on selecting high-impact projects and metrics that will reflect the project's success. This phase asks questions such as who the target customers are, their needs regarding products and services, and their expectations. The project boundaries are also defined. This phase also maps the process flow and the start/stop points.

Steps in Define phase

  • Definition of customers and requirements (CTQs)
  • Resource definition
  • Develop a high-level process map
  • Develop milestones and a project plan
  • Develop a problem statement, benefits, and goals
  • Make a project charter
  • Evaluation of crucial support for organizations
  • Identifying the team, process owner, champion

The Define phase can use tools

  • Definitions of CTQ
  • DMAIC Work Breakdown Structure
  • Process flowchart
  • Project Charter
  • SIPOC Diagram
  • RACI Diagram
  • Analysis of Stakeholders
  • Gathering Voice of the Customer


This is the second phase in the DMAIC, where must provide documentation. This includes validating and assessing the performance of the baseline. The customer survey is used to determine the shortfall. This phase collects data from multiple sources to determine the type and extent of defects. This phase can be used to determine the type of defects and metrics.

Steps in Measure Phase

  • Data collection plan development
  • Collecting data
  • Beginning Developing y = f(x) relationship
  • Determining unit, opportunity, or defect
  • The process map for different areas is shown in detail
  • Methodability and baseline sigma
  • Validating the measurement system

You can use these tools in the Measure phase

  • Benchmarking
  • Data Collection Plan/Example
  • Analyze the Measurement System
  • Process Flowchart and Value Stream Map
  • Process Sigma Calculation
  • Voice of the Customer Gathering


The Analyze phase eliminates all causes that are not Critical-to-Quality Characteristics or CTC. For success, you should have no more than three causes. It is a sign that there were not enough critical causes to be isolated. Another reason could be that the goal of the project is too ambitious. This step will help you identify any gaps between current and goal performance. You will also need to identify sources of variation and potential areas for improvement. This phase can be done using various tools, including scatter diagrams, hypothesis testing, multivariate analysis, time series charts, time series plots, histograms, Pareto charts, and fishbone diagrams.

Steps in Analyze Phase

  • Determining performance goals
  • Important few x's and the y=f(x), relationship
  • Steps for identifying value and non-value added processes
  • Recognizing the sources of variation
  • Root causes
  • Prioritize root causes

The Analyze phase can use tools

  • 5 Reasons
  • Cause and effect
  • Diagram of the Fishbone
  • Histogram
  • Hypothesis Testing
  • Non-Normal Data Analysis
  • Pareto Chart
  • Process Map Analysis and Review
  • Regression Analysis
  • Run Chart
  • Scatter Plot
  • Statistic Analysis
  • Time Series


This fourth step in the DMAIC framework ensures that all causes identified during the Analyze phase are understood. This phase aims to eliminate and control the causes that can prevent breakthrough performance. An implementation plan must also be developed and implemented. You can also use tools such as Hypothesis Testing, Regression Analysis, and Design of Experiments (DOE) or Analysis of Variances (ANOVA) to help you in this phase.

Steps to the Improve phase

  • Evaluation of potential failure modes for solutions
  • Potential solutions can be corrected or re-evaluated
  • Determining the operational tolerances of the system's potential
  • Potential solutions
  • Performing design experiments
  • Pilot studies to validate potential improvements

The Improve phase can use tools

  • 5 S
  • Brainstorming
  • Design of Experiments
  • Failure Modes and Their Effects Analysis
  • House of Quality
  • Make a mistake with proofing
  • Pugh Matrix
  • QFD
  • Simulation Software


You must monitor all improvements made to ensure sustainable changes and long-lasting results. Best controls allow for minimal monitoring of irreversible product design or process changes. Process settings, setup procedures, and other improvements can make daily operations and monitor more difficult. It is essential to ensure that the process does not revert to its original state.

Steps in Control Phase

  • Communication with business
  • Finalizing documentation and closing the project
  • Monitoring and validation of control systems
  • Capability to determine the process
  • Handoff to the process owner and transfer plan
  • Standardization and development of procedures
  • Controlling statistical processes
  • Verifying cost savings/avoidance and benefits for profit growth

The Control phase can use these tools

  • Control Charts
  • Control Plan
  • Calculations for Cost Savings
  • Process Sigma Calculation

Each phase of the five DMAIC phases is combined in implementing and maintaining six Sigma. This can help any company turn around its business.

Implementation of DMAIC

This section will look at two DMAIC implementations that use different continuous improvement models to address specific applications.

Floor yield improvement in a manufacturing workshop

This is a repeatable manufacturing process in which the product is made more often.

  • Define: Identify the product flow and the products involved.
  • Measure: Define metrics for first-pass yield or rolled first-pass yield. It will also include monitoring time to collect baseline data that is statistically significant.
  • Analyze: Look out for trends and assess the mean and standard deviation of data. Address and identify outliers. Root cause analysis is also used to identify variables that impact the yield.
  • Improvement: Identify and implement countermeasures to address root causes. Monitor the process to verify that desired yield improvements are achieved.
  • Control: Take steps to improve performance.

Evidence-based care has an impact on hospital outcomes

This second example illustrates how can improve a hospital by using principles of Lean in the DMAIC framework.

  • Define: Ask questions such as how frequently infections are occurring in hospitals and over what time frames will treatment for infection improve.
  • Measure: Measuring the current state
  • Analyze: Determine the root cause, such as the processes introducing contamination or specific steps.
  • Enhance: Use a checklist to ensure basic hygiene, sterilization, disinfectants, enhancement, and other equipment are in place.
  • Control: Implement reinforcement and training to reinforce the process and improve culture. This can also include empowering nursing staff to enforce the measures.


Six Sigma levels only allow for 3.4 defects per million products and services. Continuous efforts are made until predictable results are achieved and stable products are created.

As we have discussed, the six-sigma method deconstructs manufacturing down to its most essential components. The six sigma methodology then identifies and evaluates each step of the manufacturing process and seeks ways to increase efficiency in the business structure. This helps to improve process quality and increase bottom-line profits.

Once you have a solid understanding of the DMAIC framework, you can begin to master the six-sigma methodology. You can start with the Yellow Belt or move on to the Green Belt and Black Belt until you reach the Master Black Belt.