Six Sigma(6σ) Concept

Six Sigma(6σ) is a set of scientific approach which is developed in Motorola in 1986, followed by many upgradation and development made in six sigma. Six Sigma  is a fact of philosophy for continuous improvement in any organization. Six Sigma methodology that aims to reduce the variation in a production process and helps to improve the quality to meet the customer requirements.

 Six Sigma methodology used both statistical tool and non-statistical tool to define quality targets and tolerance in a production process. It also identify process variation causes and help to eliminate them to achieve customer quality line.

  Six Sigma Approach is a project driven it shows area of improvement and opportunity for a growth in a project. It usually done in team approach manner. The team should consist of Cross Function members of an organization (i.e., Members from Marketing, HR, Product development, Quality, Production, R&D, Technical and also from Middle & top management)

Six Sigma in compare with DPMO

DPMO (Defects Per Million Opportunity) which determines the level of possible defects which may occur  in production of 1 million parts in a production field. The following table shows the DPMO for each corresponding sigma level

Sigma level	DPMO	Yield in %
1 σ	690000	30.85
2 σ	230	69.15
3 σ	6210	93.32
4 σ	66800	99.38
5 σ	230	99.977
6 σ	3.4	99.99966

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One point info:

·       Statistical tool: It is technique of using some statistical tool to analysis data taken. Usually it require the precise and accurate data collection . Output of this analysis will be very much accuracy compare to Non-statistical approach .Some of statistical tool are Minitab, SPSS, Matlab

·       Non-Statistical tool: It is technique of choosing the test based on judgmental method or based on experience on the project .It is simple and output for this data analysis is not accurate as compare to statistical tools. Some of the techniques are Interview method, scaling technique, cluster analysis, survey.

 Six Sigma philosophy

Six Sigma is an scientific approach to a problem and help the team to solve the problem in a precise manner and to deliver a value to a customer. The following are the scientific approach steps

·         Observe important aspects in a business or a problem

·         Develop a hypothesis for your observation

·         Make a prediction based on your  hypothesis

·         Test your prediction using statistical tools

·         Discuss the distance from your observation and tried to to eliminate the deviations.

 Road map for Six Sigma(6σ)

 There are two type of approaches used in Six Sigma

·       DMAIC cycle- this is commonly used type used for process improvements of existing production line using the statistical tools.

·       DMADV- this is used for new product development process development to achieve the customer specific requirements is usually performed in a different stages of a project. It is preventive measure tool uses qualitative tool for analysis i.e., QFD, Kano model. It takes longer team and term for obtaining results.