A couple of thoughts on "leaning" people-based processes.  This is an interesting problem whether you are coming at it from a lean or a six sigma perspective.  I believe that the key issues are:  1) identifying the major areas of waste and addressing the low-hanging fruit ("quick hits"), 2) ensuring basic repeatability and predictability, while giving people with expertise the ability to make on-the-spot decisions to deal with uncertainty, and 3) using the methodology not to enforce 100% improvement, but rather to change the cultural mindset to one of continuous improvement and focus on the customer.  The last point ensures that even when the project ends, it will be a sustained effort that empowers and engages people.

I recently took on a six sigma project in a champion role that focused on how we could improve the ROI of certain marketing and sales processes within our team.  In reality it was closer to DFSS than DMAIC.  I found that it was an interesting balancing act between asking the team to be rigorous in finding the root causes vs. delivering quick hits.  The team was able to deliver about a 1.3 sigma improvement in the first pilot project, which took about 6 months including belt training, etc.  While I believe we can approach the people-based process threshold of about 3 sigma in another 6 months, the net improvement even from this initial phase was sufficient to validate the approach and shine a light on some very easy, cheap improvements that can be made that are behavioral, not dependent on systems or tools.  One of the biggest insights gained was that while the easiest scapegoat was the CRM system (since it can't defend itself), the real root causes were in our own behavior and accountabilities, and they were pretty easy to address.

Another example of Starbucks trying to use lean to improve store-based processes was recently detailed by Mark Graban in his Lean Blog.  This is an interesting study because it highlights both the pros and cons of this approach, which again generates some delicate balancing acts between getting the most out of the process while still helping people feel empowered as opposed to robotic.

Appreciate any feedback from readers on their own experiences with trying to apply lean or six sigma to processes that are 80-90% people-based.