Annex 4 - compilation of approaches
Six sigma is an approach to improvement developed at Motorola in the 1980s, which focuses on removing the causes of defects and reducing variation in processes. It has a meticulous focus on understanding wide-ranging customer needs, prioritising these and designing processes and systems to deliver to those needs. Its purpose is derived from the desire to achieve a performance level equivalent to a defect rate of 3.4 defects per million opportunities. Six sigma uses a disciplined and systematic approach look at the improvement journey from a number of related perspectives: define; measure; analyse; improve; and control (DMAIC).
Six sigma is typically a facilitated process where experts use qualitative and quantitative techniques to drive process improvement. Although the tools themselves are not unique, the way they are applied and integrated as part of a system is. Six sigma professionals undergo extensive training to be able to select and use tools to evaluate a process from various perspectives and determine which activities are to be improved. It has been embraced by a number of US companies, while application in the UK health system is more limited.
Six sigma tools help to:
- define a problem, improvement opportunity or requirements
- measure process performance
- analyse processes to determine root causes of variation, defects or poor performance
- improve process performance by addressing root causes
- control the improved process and future performance.
It is increasingly used in conjunction with lean thinking.