Six Sigma is a data driven, customer focused, and result oriented methodology which uses statistical tools and techniques to systematically eliminate the defects and inefficiencies to improve processes. It is a systematic method to measure and analyze the business processes to identify critical factors affecting business results, thereby improving the processes and establishing controls around the improved processes.
Six sigma is a widely accepted quality concept in the corporate world today. Six Sigma started its journey in the 1980s as a data driven method to reduce variation in electronic manufacturing processes in Motorola Inc. in the USA. Six Sigma became famous when Jack Welch made it vital to his successful business strategy at General Electric in 1995. Today it is used as a business performance improvement methodology all over the world in diverse industry including general manufacturing, construction, banking and finance, healthcare, education, government, KPO/BPO, IT/ Software. At present IT/ ITES sector companies are dynamically implementing Six Sigma and it is no more confined into manufacturing sector.
The term ‘six sigma’ comes from statistics and is used in statistical quality control (SQC) which evaluates process capability i.e. the numerical measure of the ability of a process to meet the customer specifications. It was originated from terminology associated with manufacturing which refers the ability of manufacturing process to produce a very high proportion of output within specifications. The sigma rating of a process indicates its yield or percentage of defect-free outputs it produces. A six sigma process is the one which produces 99.99966% statistically defect-free outputs which is equivalent to 3.4 defects per million opportunities (DPMO).
Six sigma uses a set of quality management and statistical methods and creates a team of experts within the organization (Executive Leadership, Champions, Black belt, Green Belt, Yellow Belt etc.) having specific skill sets required to carry out the six sigma project. Each six sigma project carried out within an organization follows a defined sequence of phases with quantifiable value targets e.g. reduction in process cycle time, reduce cost, increase in quality rating/ customer satisfaction index, reduction is defect rate.