HERE ARE SOME KEY CRITERIA TO CONSIDER:
WHAT IS YOUR OBJECTIVE?
Do you have specific difficult quality issues that must be resolved? Do you have a pressing need for general overall company operating improvements? Or, are you just looking for a means to force improvement into the organization?
Alternatives: Six Sigma is a powerful tool, specifically designed to resolve complex quality problems. It is NOT, however, designed to address overall operating performance issues. Lean Manufacturing, on the other hand, is an all-encompassing philosophy designed to address overall process improvement. It is a comprehensive philosophy and process with a cadre of underlying techniques.
SPEED OF RESULTS NEEDED?
How urgent is your requirement? Is this initiative a leisurely “nice to have” or is there a pressing need for quick, substantial results?
Alternatives: Six Sigma is a thorough, rigorous process. It entails a considerable amount of front-end training before any meaningful work can begin. Lean Manufacturing, when correctly applied, can begin generating large results almost immediately.
CAN WE DO BOTH?
Can we effectively transition to both Lean Manufacturing and Six Sigma simultaneously?
Discussion: To transition to a Lean environment requires a huge commitment, and focus, from the top. Lean is, in most companies, initially a foreign philosophy. The transition typically requires a culture change and a substantial commitment. This is also true of a full blown Six Sigma implementation. Attempting to do both, simultaneously, will almost always result in neither philosophy being done very well. In addition, the underlying philosophies can cause some conflict if attempted simultaneously. An effective Lean transition has an element of “Just Do It” i.e. reduce the inventory and fix the problems that arise. Conversely, the classical Six Sigma implementation is rigid and rigorous.
WHICH TO DO FIRST?
If it doesn’t make sense to attempt to do both simultaneously, is there a reason why one should be done before another?
Alternatives: Lean is an overall operating philosophy that drives the waste out of the system. The Lean process will expose problems of all sorts. In the Lean “tool kit” are a host of techniques that are utilized to resolve the exposed problems. One such technique is Six Sigma. The Lean toolkit also contains other quality improvement techniques such as Sequential Inspection, Failsafe, Source Inspection, etc.
Bottom Line: If your process is already operating Lean, and you are now facing isolated difficult quality and/or process control issues, then a Six Sigma implementation would likely be appropriate and beneficial. If, however, your company is still operating in a traditional mode, doing Lean first will almost always generate much more meaningful and timely results.
Six Sigma is a powerful tool when applied to appropriate quality and process control issues. It is NOT, however, an overall enterprise improvement methodology. The Lean Manufacturing transition process can be used to generate cash and overall global process improvements. Six Sigma methods should be then utilized, where appropriate, to resolve specific process quality / reliability issues.