People + Process = Performance

How Much Waste Are You Still Missing By Doing Lean Without Ergonomics?

It seems as though everyone is doing Lean these days—Lean Office, Lean Manufacturing, Lean this and Lean that.  Lean is a very good process improvement methodology started by Toyota.  However, Lean is frequently done without inclusion of human factors/ergonomics (HF/E).   This lack of using a human centered approach lessens the effectiveness and sustainable of Lean improvements.  This article will explain the reasons for that statement and help you understand that a significant amount of waste is still present after Lean has been done without regards to HF/E. 

Overview of Lean

Lean is based on two pillars—continuous process improvement and respect of people (safety, environment and community).  Eliminating “waste or wasteful activities” is at the heart of improvement in Lean.  There are 8 “Wastes” that are evaluated in lean:

  • Transportation
  • Inventory
  • Motion
  • Underutilization
  • Defects
  • Over-processing
  • Over-production
  • Waiting

The biggest one for Ergonomics is the “Waste of Motion”.  Wasted Motion impacts external and internal productivity.  Lean mainly focuses on external productivity which leaves internal productivity virtually ignored.  What does this mean?  It means that no one is paying attention to the ability of an employee to produce more output with no increase in risk of injury or errors.  The problem for Lean only practitioners is the inability to see and quantify “wastes” related to hidden human performance issues.  An ergonomist looks at processes involved along with the performance and behaviors of the humans to uncover the hidden human performance “waste”.  This consists of identifying and quantifying unnecessary movements, “risky” movements and cognitive processes.

Lean Levels of Waste

There are four levels of waste in Lean.  In my experience, most companies stop at the first waste level because it is the quickest and easiest to do.  To use the overused cliché, level 1 waste will take care of the ‘low hanging fruit’.

  • Level 1—Gross waste (poor plant layout, rejects, returns, damage, dirty equipment, idle material, etc.)
  • Level 2—Process and Method (poor workstation design, no maintenance, equipment issues, unsafe methods, long changeovers, etc.)
  • Level 3—Microwaste (bending/reaching, excess walking, searching, no SOP, etc.)
  • Level 4—“Nanowaste” (cognitive, upper extremity ergonomic risk—force, hand/wrist/finger motions, gets and grasps, etc.)

Levels 2-4 are where HF/E is definitely needed.  People are the biggest source of quality, productivity and cost. Without including the human factor, the reduction and/or elimination of non-value added waste related to people will be missed.  The impact to improve production, quality, reduce costs and improve health and safety will be lost.  There is a direct correlation between be risk reduction and cycle time reduction, i.e. as risks are reduced (less wasted or risky motions) the cycle time is reduced (increased efficiency).

What about Six Sigma?

I feel I need to include Six Sigma into this discussion as well since it is also a common process improvement methodology that is frequently combined with Lean.  The term LeanSix is becoming commonplace.  Six Sigma uses a process known as DMAIC:  Define, Measure, Analyze, Improve and Control.  The purpose of Six Sigma is to reduce the number of defects to a six sigma level, i.e. .000001.  A defect is a nonfulfillment of an intended requirement or reasonable expectation for use.  There are four classifications related to defects—I will state them in relation to injuries and financial loss:

  • Class 1:  critical, leads directly to severe injury or catastrophic economic loss
  • Class 2:  Serious, leads directly to significant injury or economic loss
  • Class 3:  major problems with respect to intended normal use, major economic loss
  • Class 4:  minor problems with respect to normal use, slight economic loss

Unfortunately, it too lacks HF/E.  So where does HF/E fit into Six Sigma?  It all comes down to the human factor again—people can create variation in the process that can lead to slower deliver times, poor quality and increased cost.  How many times have you heard (or even said), “We don’t have any ergonomic issues.” Or, “Our injury/illness rates are at or below our industry standard so we are doing fine.”  Do these two statements mean all is well and that you are operating at World Class Performance, i.e. Six Sigma level?  Or is there an “Iceberg” at your company where there are very few official reports of discomfort, difficult tasks or injury but there are numerous “hidden” facts and data related to human limitations that are lurking beneath the surface?  Whenever I hear a company owner or manager say, “No problems here” I tend to think s/he should be saying “No problems that I care to know of here”.  There are always processes and risk factors that exist but without admitting they exist and looking for them it is easier to pretend all is fine until the ship hits the iceberg.  Remember the progression of defects starts with minor (invisible), goes to major (probably still invisible) until it becomes serious to critical (visible—Iceberg!).  One can use this same analogy for ergonomics—advanced ergonomics (invisible), proactive ergonomics (invisible) and reactive ergonomics (visible—Iceberg!).

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.