Six Sigma

Six sigma and Mind Mapping

This site is a comprehensive review of the important Six Sigma strategies, and ways that Mind Mapping improves the Six Sigma process.

Six Sigma made easy

  1. What is Six Sigma
  2. DMAIC
  3. DMADV
  4. SIPOC
  5. Critical X

What is Six Sigma?

First developed by Motorola in 1986, and made main stream in 1995 by Jack Welch of General Electric, Six Sigma is a business management strategy which seeks to improve the quality of process outputs by identifying and removing the causes of defects. Using quality management methods Six Sigma also attempts to minimize variability in business processes.

Recently, Mind Mapping and Work Breakdown Structures (WBS) have become popular methods to assist Six Sigma professional in achieving 99% free from defects, the ultimate goal behind the Six Sigma strategy.


When projects are aimed at improving an existing business process, DMAIC is the preferred Six Sigma methodology used. The DMAIC methodology is used when a product or process currently exists at your company but is not meeting customer specification or is not performing as required.


Six Sigma DMAIC


5 Phases of DMAIC

  • Define the problem, the voice of the customer, and the project goals, specifically.
  • Measure key aspects of the current process and collect relevant data.
  • Analyze the data to investigate and verify cause-and-effect relationships. Determine what the relationships are, and attempt to ensure that all factors have been considered. Seek out root cause of the defect under investigation.
  • Improve or optimize the current process based upon data analysis using techniques such as design of experiments, or mistake proofing, and standard work to create a new, future state process. Set up pilot runs to establish process capability.
  • Control the future state process to ensure that any deviations from target are corrected before they result in defects. Implement control systems such as statistical process control, production boards, visual workplaces, and continuously monitor the process.


When a product or process does not currently exist at your company but needs to be created, DMADV is the preferred Six Sigma methodology used. DMADV is used to improve the new process, as opposed to improving an existing product or process.


Six Sigma DMADV


5 Phases of DMADV

  • Define the project goals and customer (internal and external) deliverables, as well as the enterprise strategy.
  • Measure and determine customer needs and specifications, CTQs (characteristics that are Critical To Quality), product capabilities, production process capability, and risks.
  • Analyze the process options to meet the customer needs, to develop and design alternatives, create a high-level design and evaluate design capability to select the best design.
  • Design (detail) the process to meet the customer needs, optimize the design, and plan for design verification.
  • Verify the design performance and ability to meet customer needs, set up pilot runs, implement the production process and hand it over to the process owner(s)


SIPOC is a tool used in process improvement, which summarizes the inputs and outputs of one or more processes, and is displayed in table form. SIPOC stands for suppliers, inputs, process, outputs, and customers which form the columns of the table.


six sigma SIPOC


SIPOC is used to emphasize putting the customer’s needs first. Process information is filled in starting with the customer and working upstream to the supplier. The SIPOC is often presented during the “define” phase of the DMAIC process.

3 Uses of SIPOC

  1. To give a high level overview to people who are not familiar with a process.
  2. To reacquaint people whose understanding of a process has become outdated due to process changes.
  3. To assist people in defining a new process.


Here are a few aspects of SIPOC that may not be readily apparent

  • A supplier or customer may be internal or external to the organization that performs the process.
  • Inputs and outputs may be materials, services, or information.
  • Capturing the set of inputs and outputs is the focus rather than the individual steps of the process.


Critical X

Critical X is a business process input that has a large degree of influence on the quality of the final product or outcome. The dynamic of the Critical X and process improvement is such that by improving the Critical X, the process improvement is realized. For example, the largest measurable gain in quality can be realized by improving the quality of the Critical X.

Critical to X is defined as a general term which refers to the various methods used in optimizing a key measurable characteristic that is ‘Critical To’ the performance or customer expectation.