Six sigma vs lean manufacturing

SIX SIGMA VS LEAN MANUFATURING

Six Sigma

Method based on world-class business-performance benchmark (3.4 defects PPM) and on providing the organizational structure to make them. It is used toimprove efficiency and effectiveness through data and facts achieving the customer’s satisfaction. Project-by-project cross-functional teams realize gap analysis in order to measure the existingperformance and compare it to the desired performance. “Black-belt” (active senior) management is required to guide the decisions taken by the teams. Continuing on the “belts” subject, the metaphor isreferred to Judo which literally means “adaptable way of life” this relates to self-perfection and the ability to exceed one’s capabilities through knowledge and training in order to obtain the differentbelts: yellow, green and finally black. Other tools used by 6σ philosophy are: (1) DMAIC model (Define, Measure, Analyze, Improve, and Control) in order to eliminate defects; (2) FMEA (Failure Mode andEffects Analysis) risk avoidance strategy; (3) process mapping; (4) poka-yoke.
On the following figure, William Truscott, writer of Six sigma: continual improvement for business: a practical guide,enumerates the features that set apart this method form others.

Lean Manufacturing

Method based on the value stream or total cycle of activity where the processes flow with “no stalls, nodisruptions, no disconnects or backtrack loops” (Carreira, 2005). The demand of the value stream is dictated by the costumers in a pull-system, where production is done when required, not before or after.The emphasis lies on the concept of “no-waste”, that is to say that only activities that add value to the finished product in the eyes of the costumer must be done. This is a philosophy used by smalloperational teams for doing more with less by effectively and efficiently using all of the company’s resources. All this can be achieved by using the 5 Lean Principles: (1) specify what creates value...