What is Six Sigma? Features, Methods and Benefits

Origin of Six Sigma

Carl Friedrich Gauss (1777-1855) introduced the concept of the normal curve, which is regarded as the standard measurement and roots for Six Sigma. Six Sigma originated at Motorola in the early 1980s, in response to achieving 10X reduction in product-failure levels in 5 years. Engineer Bill Smith invented Six Sigma, never knowing the scope of the craze and controversy he had touched off. Jack Welch capitalized the concept of Six Sigma by introducing it as a business strategy at General Electric in 1995. Six-Sigma is based on various quality management theories.

The central idea behind Six Sigma is that if you can measure how many “defects” you have in a process, you can systematically figure out how to eliminate them and get as close to “zero defects” as possible. Six Sigma is a highly disciplined process that helps us focus on developing and delivering near-perfect products and services. It is a measure by which it eliminates the defects in production, manufacturing, and development of any product, as well as service.

Introduction of Six Sigma principles are lowering the defect rate to a minimum range. Various sectors such as telecommunications, healthcare, finance, education and service industry are using this concept. It focuses on continuous improvement of the process to meet the objectives and business goals. Six Sigma seeks to improve the quality of process outputs by identifying and removing the causes of defects (errors) and minimizing variability in manufacturing and business processes. Six Sigma uses a set of quality management methods, including statistical methods, and creates a special infrastructure of people within the organization who are experts in the methods.

Features of Six Sigma

  • Six Sigma’s aim is to eliminate waste and inefficiency, thereby increasing customer satisfaction by delivering what the customer is expecting.
  • Six-Sigma follows a structured methodology, and has defined roles for the participants.
  • Data drives the Six-Sigma process and it requires accurate data collection for the processes.
  • It is about putting results on Financial Statements.
  • Six Sigma is a business-driven, multi-dimensional structured approach for −
    • Improving Processes
    • Lowering Defects
    • Reducing process variability
    • Reducing costs
    • Increasing customer satisfaction
    • Increased profits

Methods in Six Sigma

  • DMAIC : Define Measure Analyse Improve Control
  • DMADV: Define Measure Analyze Design Verify
  • DMAIC refers to data-driven quality strategy for improving process.


It is extremely important to define the problem that needs attention. Leaders have to identify and then address the issue. Defining the process which is unproductive is the beginning of this procedure. In this process,

  • Formation of a project team.
  • Develop a project charter.
  • Develop the SIPOC process map (Suppliers Input Process Output Customers)


A team has to collect data on the current process that is being performed. Only when data is collected and one has numbers in hand, there can be the scope of improvement.


After the collection of data, the team then reviews the data. Analyzing this data and the process together leads to the reason for wastes, defects, etc.


It is time for the heads of the company to now come together to find a solution. Ideas can be collected within the company as well as outside. The correct solution will definitely result in improvements.


Though improvement has been achieved, passing this structure to the employees who have been working in the earlier process is of great importance. This process is called the Control phase where one needs to maintain the improvement achieved.

DMADV refers to a data-driven quality strategy for designing products and processes

  1. Define: Define the problem or project goals that need to be addressed.
  2. Measure: Measure and determine customers’ needs and specifications.
  3. Analyze: Analyze the process to meet the customer needs
  4. Design: Design a process that will meet customers’ needs
  5. Verify:  Verify the design performance and ability to meet customer needs

Key Concepts of Six Sigma

At its core, Six Sigma revolves around a few key concepts.

  • Critical to Quality − Attributes most important to the customer.
  • Defect − Failing to deliver what the customer wants.
  • Process Capability − what your process can deliver.
  • Variation − what the customer sees and feels.
  • Stable Operations − Ensuring consistent, predictable processes to improve what the customer sees and feels.
  • Design for Six Sigma − Designing to meet customer needs and process capability.

Benefits of Six Sigma

Six-Sigma offers six major benefits that attract companies −

  • Generates sustained success
  • Sets a performance goal for everyone
  • Enhances value to customers
  • Accelerates the rate of improvement
  • Promotes learning and cross-pollination
  • Executes strategic change

Implementation of Six Sigma

First and foremost measuring the current variation is of utmost importance. Variation can never be eliminated to a zero. Variation is inherent. But it can definitely be reduced. To reduce it needs to be measured, and to measure one needs to focus and wherever there is the focus there is an improvement. Thus a process has to be selected. To this, the six sigma project has to be applied. If there is an improvement, it will definitely show in the form of better quality, increased productivity and reduced wastage, lower cost of production and a higher level of customer satisfaction.


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