Lean & Six Sigma, More In Common Than You Think

Measured BenefitAfter spending years facilitating and using lean and six sigma to improve businesses I have come to the conclusion that these well known methods have more in common than you would think.  Lean works to improve any process by identifying and eliminating waste, while six sigma works to improve any process by identifying and eliminating/reducing defects and errors.  The common thread connecting these methods is the end result of process improvement through the relentless pursuit for perfection.

To begin looking for commonalities between these two methods, history provides some interesting learning points.  Throughout  time man has searched for ways to excel and constantly improve any process created.  For this article we will identify a point in time where the explosion of lean and six sigma took place.


Lean Manufacturing is a term developed by Professor James P. Womack in a book he authored in 1989 called “Lean Thinking”, to explain the phenomenon he saw taking place in the automotive industry.  He noticed the revolution of the Japanese vehicle and wanted to understand the dynamics taking place.  He learned the Japanese were using a methodology of identifying seven wastes of manufacturing and then using different improvement techniques to eliminate these wastes.

The method can be summed up in five steps:

1. Identify the sequence of activities called the “value stream”

2. Identify which features create value

3. Make the activities flow by eliminating waste

4. Create pull

5. Perfect the process

These steps are quite effective at improving the process and creating value for the customer.


During the time that lean manufacturing was becoming known, Six Sigma was being introduced within the Motorola organization by Bill Smith, a process engineer during the 1980’s and then became a system wide practice by 1989.  At this time, it was determined that the traditional quality level – measuring defects in thousands of different opportunities – did not provide enough “granularity” (breaking down into smaller, more manageable parts), so “defects per million opportunities” was created.  This allowed a deeper examination into the root-cause or contributing factors of defects and errors.  A new quality standard was adopted and the methodology of six sigma was developed as the corrective process.

Six Sigma is a five step statistical method designed to improve any process through the stabilization and prediction of results, thus leading to the elimination of defects.  Defects are characterized as anything that could lead to customer dissatisfaction.

The five steps are:

1. Define process improvement goals consistent with customer expectations

2. Measure key aspects of the process and collect relevant data

3. Analyze the data to establish critical process input to process output relationships

4. Improve the process based on the obtained data driven knowledge

5. Control the process so that deviations from the process are corrected before they appear as defects

These steps, as noted with the lean steps, are very effective at improving the process and creating customer value.


As I continued to work with both of these wonderful improvement processes, I became very adept at applying them concurrently while driving for quick and powerful results.  Over time, it became evident that both methods were driving for the same result…relentless continuous improvement!  So, if you practice Lean, Six Sigma or both, remember that they are not diametrically opposed but rather aligned to deliver excellence in any business process.