People + Process = Performance

How Much Waste Are You Still Missing By Doing Lean Without Ergonomics? (Part 2)

Lean Six Sigma Steps and Tools

Let’s look at some of the tools commonly used in Lean and Six Sigma and then see what’s missing.  The first step in either process is to define the problem.  This is done through employee/customer feedback (VOC), current data (costs, cycle time, rates, injuries, etc.) and production/quality issues.  The next step is to measure the problem.  Common tools for this step include fishbone diagram, pareto analysis, value steam mapping, task analysis for value or non-value added actions, statistical analysis for cycle time variation (box and whisker plot), etc.  The third step is to come up with solutions and analyze results of them prior to implementation.  Then the solution is implemented, results are measured and analyzed again to see if the change is what was desired which takes us to the control and sustain part of the six sigma process.  Which of those tools takes into consideration the humans within the process?  They are great engineering tools but without a human focus.  


Ergonomic Tools

In order to capture the human element within processes one has to use ergonomic tools.  Some tools take the existing engineering tools and modify it so it focuses on the human, i.e. ergonomic fishbone diagram and a modified affinity diagram.  Other tools need to be added to measure and capture ergonomic risk and the physical capability forces (% of maximum muscle voluntary contraction force used during one or more tasks) beset on the human.  In addition, similar to Lean, there are ergonomic tools that allow one to measure the time savings expected from modifying the work to improve/eliminate risky motions.  There are time savings standards for many motions and activities such as the elimination of tool use, finger and hand motions, reaching, bending, siting, etc.  The purpose is of these tools is to analyze the impact of ergonomic improvements on a job sequence.  The impact can be examined for each recommendation alone or as a whole.  This allows for an accurate prediction of potential cost savings due to time reduction.  Being able to quantify time savings for ergonomic risk factor reduction makes the business case clear and objective to all involved.


There have been times when an area or process has been “Leaned” and I’ve come in after the fact and still see risky, needless motions that are slowing down the process.  After modifications were made to eliminate them the process was improved another 20-30%.  How many COOs and managers would be very disappointed to know that they are missing out on an additional 20-30% savings because the human factor was no considered?  I’d say all of them.  With the economy still not being on solid footing how many COOs and managers can afford not to incorporate the human factor into their “process excellence” programs?


Operational Human and Process Excellence

It is my strong belief that Operational Human and Process Excellence is achieved only when all three are combined:

  • Lean = continuous waste reduction
  • Six Sigma = defect free work
  • Human Factors/Ergonomics = risk reduction (physical, cognitive  and organizational)

Granted, combining all three takes more time than just doing one and it may result in having to add another person to the team; however, the results and rewards are well worth the time and effort.