Six Sigma VS Lean and ISO
Comparison with Lean
Lean is another popular methodology that has come into prominence. Lean and Six Sigma each have their own strengths in different applications. The two methodologies can be combined or applied in different situations to achieve the best results. One such example is to use Lean to study and analyse system level performance, identify bottleneck processes for improvement using the Six Sigma methodology. One can also choose a suitable methodology by determining the level of confidence required iin relation to the solution desired. DMAIC is a methodology is rigorous and highly data driven. The Lean KAIZEN event focuses more on speed and relies more on experience and knowledge. Therefore, if you need to be very certain that your solutions are correct it may be more appropriate to spend more time and follow the DMAIC methodology. If the process has reached entitlement (basically meaning the process no longer has the capability to be iimproved or cannot meet the standards required) then you would use the DFSS method to achieve a breakthrough. If a lower level of confidence is permissible, it may be more appropriate to use the Kaizen method and take advantage of the faster implementation and the earlier realisation of benefits.
Comparison with ISO
The following table shows a comparison between the ISO and Six Sigma concept.
|Standards based||Methodology based|
|Prescriptive standards||Concept and tools for flexible application|
|Organisation is certified by an external body||People are certified by the organisation|
|Focus on documentary evidence such as policies, guidelines, work instructions||Focus on improvements, financial and non-financial benefits|
|Usually a basic criteria to be a supplier||Driven by the organisation, its customers and competitors|
|Sustenance ensured through regular audits and assessments||Sustenance through process control and continuous improvement|