There still seems to be an ongoing debate about the benefits of combining Lean and Six Sigma and whether organizations should consider doing so. Both methodologies focus on the customer. Lean declares a “war on waste,” while Six Sigma declares a “war on variation.”
Both Lean and Six Sigma empower people to create process stability and a culture of continuous improvement. Many problem identification and problem solving techniques are used in both methodologies. These include brainstorming, fishbone diagrams, 5-Whys, Pareto analysis, 8-Ds, FMEA, and others. Both place a heavy emphasis on careful problem definition.
Should Lean and Six Sigma coexist in an organization? The answer should be a resounding “yes!” Implementing Lean provides stability and repeatability in processes. Once stability is achieved, much of the variation goes away and the process becomes more consistent.
Lean tools should be utilized to:
- Eliminate waste
- Simplify processes
- Improve flow
- Reduce inventory
- Reduce lead time
- Error proof processes
Six Sigma tools should be used to:
- Minimize variation
- Eliminate quality issues
- Identify and eliminate root causes
All organizations have a combination of both sets of issues and combining Lean and Six Sigma reflects a more holistic and synergistic approach to continuous improvement. The two are complementary tool sets, not competing philosophies.