Six Sigma definition

A defined set of tools and methods designed to help organisations improve the efficiency of processes and the quality of outputs. Six Sigma was developed by Motorola in 1985 and popularised by well-known executive Jack Welch during his tenure with General Electric in 1995.

Six Sigma has two aims: removing errors from processes and improving consistency by minimising variation in output.

The term originates from manufacturing methodology – a sigma rating reveals the percentage of defect-free products coming off an assembly line. The sixth sigma refers to a percentage equal to 3.4 defects per million.

One part of the Six Sigma method involves creating an infrastructure of experts within the organisation who ‘own’ a particular quality management method used in Six Sigma – these people are known by various titles, including ‘black belts’ and ‘champions.’

Critics of the Six Sigma process point to its ‘rigid’ structure as being inflexible for the changing needs of organisations and also say it has the potential to stifle innovation. Some quality experts also suggest the Six Sigma methodology is unoriginal and incorporates basic facilitators of quality control.