Six Sigma was a management system that was developed by an engineer from Motorola in the year 1984 to reduce the number of defects that were produced in a product. Since then many other companies and business have used Six Sigma to reduce their defects and made better quality products. Six Sigma is more of a data-driven management process which aims to improve the quality of a product or service by analysing and measuring the number of defects that were raised while making a product and the ways to eliminate such defects in the future to make better products. The term “defect” was used widely by many companies after the Six Sigma concept was introduced.
In the 1920s, Walter Shewhart, a statistical quality controller said that while manufacturing any product, Three Sigma from the mean is considered as a tipping point where there are many defects, and the product will be corrupted. Many people accepted this proposal until Bill Smith, the engineer from Motorola had proposed the Six Sigma concept. As efficiency can never be one hundred percent, we can never achieve zero defects. Six Sigma allows about 3.4 defects per million while Three Sigma allows 66,807 defects per million.
Baseline Sigma tells us how far or close a company is from achieving Six Sigma. Once all the data needed for Six Sigma is collected, a company creates a baseline sigma, and that is used to access the future progress of the company. Businesses have claimed that they have had up to 50% cycle time improvement, reduced cost, increased satisfaction from the customers and they said that they were able to produce more reliable products. Motorola holds the trademark for Six Sigma, and it is known that the concept is quite costly to implement and it would take years to see the final results.
There are two methodologies used in Six Sigma, one is the Six Sigma DMAIC, and the other one is the Six Sigma DMADV.
Six Sigma DMAIC:
DMAIC is short for define, measure, analyse, improve and control.
Define: Define is to identify the goals of a project and all the things that are to be delivered to the customer.
Measure: Measuring is the process of understanding the current performance of the business or the company.
Analyse: Once the performance is measured, you need to analyse what is causing the business not to perform well. Here you find out the root cause of the defects that are caused.
Improve: Now that you found the root cause, you need to start eliminating them one by one.
Control: Controlling is to manage the performance of the company in the future so that those defects will not be caused again.
Six Sigma DMADV:
The first three concepts of DMADV are the same as DMAIC. DMADV is short for define, measure, analyse, design and verify.
Design: Designing is to create a product which would meet the expectations of the customer.
Verify: The design needs to meet the needs of the customer.