What is Six Sigma?

Six Sigma (often abbreviated as 6) is a statistical-based quality-control program that emphasizes the reduction or elimination of defects in a product, a process, or a service through the application of certain process-improvement techniques and tools.

How is Six Sigma Used?

Introduced by Bill Smith of Motorola, Inc in the mid-1980s, Six Sigma employs a data-driven approach that ensures that at least 99.99966% (or 3.4 parts per million) of all products, processes, or services are defect-free. Over the years, the Six Sigma process has evolved to encompass various business-management strategies such as:

• Meeting customer requirements.
• Boosting customer retention.
• Refining and perpetuating products and services.
• Reducing costs and increasing profits.

Virtually all industries come under the scope of Six Sigma. There are several organizations that are involved in Six Sigma training and conferring certifications such as yellow belts, green belts, and black belts.

Even More on What is Six Sigma

Six Sigma employs a disciplined statistical approach to effect improvements in a manufactured product, a business process, or a commercial service. Although developed by Motorola in the mid-1980s, Six Sigma was enthusiastically adopted by General Electric (GE) by the early 1990s under the leadership of Jack Welch. At present, thousands of businesses, especially those that typically employ statistics, financial analysis, and project management to achieve better business performance, have already integrated Six Sigma methodologies into their business strategies. The USP of Six Sigma is its emphasis on qualitative measurements of success over qualitative markers. Six Sigma has evolved into a comprehensive quality-control process with three distinct roles:

• Role 1 - Statistical Benchmark: Six Sigma has laid down certain ground rules that a business process must follow in order to be certified as efficient. According to the benchmarks set by Six Sigma, a business must ensure that at least 99.99966% (or 3.4 parts per million) of all products, processes or services are free from defects.
• Role 2 - Training Initiative: Six Sigma provides training and certification programs to businesses that are interested in implementing the core principles of the doctrine. Six Sigma offers multiple levels of certification, starting with the basic white belt and culminating in the black belt.
• Role 3 - A Process-improvement Philosophy: Six Sigma is a process-improvement philosophy that is applicable to all businesses and processes.

Six Sigma Methodologies

There are two distinct methodologies that Six Sigma projects can follow - DMAIC and DMADV (DFSS). Both methodologies comprise five phases each. 

DMAIC 

This methodology is utilized by projects that are formulated to upgrade existing processes. Its five phases are described as follows:

1. Define: This phase defines the customers, their requirements, and their expectations.
2. Measure: This phase measures the performance of the core business processes.
3. Analyze: This phase analyzes collected data and process maps to discover the underlying causes of defects and identify areas of improvement.
4. Improve: This phase involves designing innovative solutions to improve the target process.
5. Control: This phase involves controlling the new implementations and avoiding any regressions.

DMADV (DFSS) 

This methodology, also known as DFSS ("Design For Six Sigma"), is utilized by projects that are involved in creating a new product or process designs. The following are the five phases of this approach:

1. Define: This phase defines the design goals keeping in mind the interests of both the organization as well as its stakeholders.
2. Measure: This phase measures characteristics that are critical to quality (CTQ). It also measures and reassesses risk and estimates product potential and capacity of the production process.
3. Analyze: This phase provides design alternatives. It includes several steps such as creating and evaluating conceptual designs and developing the best possible design keeping in mind the total life cycle cost of the design.
4. Design: This phase involves creating a detailed design of the improved alternative.
5. Verify: This phase verifies and validates the improved alternative design. This is followed by the deployment of the new process, together with detailed documentation of all vital knowledge gained during the process.