SIX SIGMA

"Six Sigma" means a failure rate of 3.4 parts per million or 99.9997% perfect; however, the term in practice is used to denote more than simply counting defects.



Six Sigma can now imply a whole culture of strategies, tools, and statistical methodologies to improve the bottom line of companies. In all, six sigma is a rigorous analytical process for anticipating and solving problems.


It is essentially based on three underlying facts -


 a) you can manage what you measure,



 b) you can measure what you define, and



 c) you can define what you understand.



The objective of six sigma is to improve profits through defect reduction, yield improvement, improved consumer satisfaction and best-in-class product / process performance.


There are five fundamental steps or phases in a Six Sigma improvement project, commonly known as DMAIC:


1. Define (D)


2. Measure(M)


3. Analyze(A)


4. Improve(I)


5. Control(C)


Each phase is designed to ensure


(1) that companies apply the six sigma technique in a methodical and disciplined way;



(2) that Six Sigma projects are correctly defined and executed;



(3) that the results of these projects are sucessfully incorporated into running the day-to-day business.



The Define phase is critical in ensuring the success of a Six Sigma project. The project’s purpose and scope is defined and background on the process and customer is obtained.



A key deliverable of the Define phase is the Project Charter, which among other items contains the Problem Statement, Goal Statement, Constraints, Assumptions, and Project Plan. In addition to the Project Charter, a high level map of the process is generated along with a list of what is important to the customer.



The Measure phase serves to validate and refine the problem and begins the search for root causes. A more focused problem statement can be generated using data that pinpoints problem location and baselines the current process capability (sigma).



In the Analyze phase, statistical methods and tools are used to identify and confirm root causes of defects. Not only must analysis of the data be performed, but also an in-depth analysis of the process to ensure an understanding of how the work is actually being done must be performed to identify inconsistencies or problem areas that might cause or contribute to the problem.



The Improve phase focuses on discovering, refining, and implementing solutions to the root causes of the problems identified in the Analyze phase. Every attempt should be made to maximize the benefits of proposed solutions. 


 To ensure that the same problems do not reoccur, the processes that create the product or service are monitored continuously in the Control phase.