Lean and Six Sigma are powerful tools and methodologies that organisations use to improve the excellence of what they do. There are differences between the areas they cover, but they are often used in a complimentary fashion. This is seen as Lean Six Sigma.
Six Sigma
seeks to improve the quality of the output of a process by identifying and removing the causes of defects and minimising variability in manufacturing and organisational processes. It uses a set of quality management methods, and creates a special infrastructure of people within the organisation, who are experts in these methods. Each Six Sigma project carried out within an organisation follows a defined sequence of steps and has specific value targets, for example: reduce process cycle time, reduce pollution, reduce costs, increase customer satisfaction, and increase profits. A six sigma process is one in which 99.99966% of all opportunities to produce some feature of a part are statistically expected to be free of defects (3.4 defective features per million opportunities).
Lean Six Sigma
is a methodology that relies on a collaborative team effort to improve performance by systematically removing waste, combining lean manufacturing/lean enterprise and Six Sigma to eliminate the eight kinds of waste (muda): Time, Inventory, Motion, Waiting, Over production, Over processing, Defects, and Skills (‘TIMWOODS’). It also makes use of the DMAIC approach to problem-solving and improvement:
- Define The purpose of this step is to clearly articulate the business problem, goal, potential resources, project scope and high-level project timeline. This information is typically captured within a project charter document. You can then write down what you currently know, seek to clarify facts, set objectives, and form the project team.
- Measure. The purpose of this step is to objectively establish current performance as the basis for improvement. These will be compared to the performance metric at the conclusion of the project to determine objectively whether significant improvement has been made. Good data is at the heart of the DMAIC process.
- Analyse. The purpose of this step is to identify, validate and select root cause for elimination. The top 3-4 potential root causes are selected for further validation. A data collection plan is created and data are collected. This process is repeated until “valid” root causes can be identified.
- Improve. The purpose of this step is to identify, test and implement a solution to the problem; in part or in whole. This depends on the situation. Identify creative solutions to eliminate the key root causes in order to fix and prevent process problems. However, the purpose of this step can also be to find solution options without implementing them.
- Control. The purpose of this step is to sustain the gains and monitor the improvements to ensure continued and sustainable success. Organisations can create a control plan, and update documents, business process and training records as required.
IiE have specialists to assist with your Lean Six Sigma needs, and you can find out more here.