Lean Six Sigma:

LEAN SIX SIGMA is a business improvement methodology which combines (as the name implies) tools from both Lean Manufacturing and Six Sigma. Lean manufacturing focuses on speed and traditional Six Sigma focuses on quality. By combining the two, the intended result is better quality faster.

This strives to mitigate significant failure modes of "Quality only" Six Sigma when it is applied to reducing variation in a single process step (sub-optimizing), or to processes which are not value added to the customer.

Typical application of Lean Six Sigma is,
1. Identify the processes (in a functional department or business) most important to delivering customer value.
2. Map these processes using Value Stream Mapping.
3. Identify the bottlenecks / constraints in the value stream.
4. Apply variation reduction through DMAIC/DMAD(O)V to standardize the relevant process steps.

Many companies such as Textron with mature Six Sigma implementations added lean manufacturing tools to the existing toolbox. Others such as Caterpillar brought on consultants to develop a comprehensive program others such as Honeywell developed their own methodology upon a merger where one partner (Allied Signal) was mature in Six Sigma and the other in Lean. And General Electric, developed Lean Sigma in conjunction with their Customer Satisfaction process (Net Promoter Score or NPS) to get the most benefit from DFSS and Lean. The United States Department of Defense considers Lean Six Sigma its "tool of choice" for "business transformation.