Six Sigma Principles

Six sigma principlesThe Six Sigma methodology is one that focuses on creating quality products and eliminating defects. Though Six Sigma is a vast idea that spans a number of Lean philosophies and methods, at its core, Six Sigma is driven by three principles:

Process Improvement— Companies should take consistent action to eliminate root causes of deficiencies within its production processes.

Process Design (or re-design)— Don’t be afraid to challenge, question, or revamp existing processes to be more consistent, efficient, and simple.

Process Management—This element demands workers take actions like defining processes, measuring performance, and analyzing data so that company has better understanding of production and therefore can pinpoint where processes need to be improved.

Six Sigma System

These three principles encompass the following elements:

  • Six Sigma aims to make continuous improvements to production. It believes stable and predictable production results are crucial to sustaining success in the long-term.
  • Manufacturing processes can—and need to be—measured, analyzed, and controlled.
  • In order for Six Sigma to succeed in a company, company-wide effort, commitment, and cooperation is required. Everyone, from machine operators to QA auditors to managers—need to take part in Six Sigma if changes are to take hold.

Six Sigma’s originality stems from its focus on ongoing improvement, working toward specific markers, and in-depth team involvement. It’s this attention to detail that allows the strategy to be so successful and stand out from other quality management philosophies. More specifically, Six Sigma differs from other QA initiatives in the following ways:

  • Concentration on measurable goals like concrete financial returns
  • Relies heavily on strong and passionate management leadership and support
  • Uses quantifiable, proven data and statistics to make decisions rather than forecasts, assumptions, or guesswork

Six Sigma Concepts

Value Stream Mapping— a process that maps all the steps involved in making a product. It reveals where waste occurs.

Overall Equipment Effectiveness (OEE)A calculation formula for assessing how productive a facility is on a day to day basis.

CTQ tree— Critical-to-quality trees are figures that help companies translate customer needs into actionable production specifications.

5 Whys— Usually used in the Analyze phase of Six Sigma, this strategy of asking “Why?” five times helps get to the root cause of production problems.

Axiomatic design— This design concept posits a systematic approach for the design of products for better uniformity and consistency.

Process Mapping— a tool that visually communicates the flow of work in a facility/ production process.

Fishbone/Ishikawa diagramClosely related to the 5 Whys strategy, this diagram visually represents how asking questions about a problem can lead to the root cause.


DMADV project methodology, known as DFSS (Design for Six Sigma) features five phases:

Define design goals that align with customer needs and business strategy Measure and identify characteristics that are critical to quality (CTQ). Measure

product capabilities, production process capability, and measure risks

Analyze to develop and design alternatives

Design an improved alternative, best suited per analysis in the previous step

Verify the design, set up pilot runs, implement the production process and hand it over to the process owner(s).

It’s important to note that to execute the individual phases of DAMIC or DMADV, use as many common quality-management tools as necessary to get the job done.

Before beginning a Six Sigma journey, or if you are looking to update your current Six Sigma efforts, getting certified is probably the best first step. It will help future projects and ensure proper and successful implementation of Six Sigma.

Additional Resources