Ergonomics Task Analysis:
Picking the Right Tool
Dan MacLeod
www.danmacleod.com
Original publication: Occupational Hazards, January, 1995, pp. 71-73.
Ergonomics task analysis is currently the source of much confusion in many companies,
not to mention in regulatory and standards-setting bodies. Resources are being wasted,
ergonomics programs are being distracted, and the employees are not getting much benefit.
On one hand, too many job analyses are being generated today which are far too long and
academic for what is needed. It is like giving a brain scan to a patient with a head cold,
when a simple prescription of aspirin and chicken soup would do.
On the other hand, when ergonomics is introduced in the
workplace as a matter of common sense, some people falsely gain the impression that the
field of ergonomics has little to offer in terms of engineering rigor. What sometimes gets
lost by trying to demystifying ergonomics is its value in providing precise data, design
specifications, and ability to measure and compare. Fortunately, much of the confusion can
be clarified by applying the phrase "pick the right tool for the right job." The
tools on ergonomics are many and varied — some basic and some complex. The technique
and approach used must to the needs and goals of the specific workplace.
Problems vs. Solutions
One good way to help select the right tool is to differentiate between:
(a) documenting problems, and
(b) finding solutions.
If your goal is to document problems, then rigor and precision in conducting an
analysis are critical. However, if your goal is to find solutions, often this step of
determining the problem is fairly simple.
For many jobs, it can take as little as a few seconds for anyone with a rudimentary
understanding of ergonomics to recognize problems. There may be no particular need to stop
to evaluate the problem any further. You can almost immediately focus on evaluating
options for improvement.
This distinction is crucial. Spending time continuing to document problems can be a
distraction and counterproductive, and further study of the problem may lend no insights
to problem solving at all. I have seen whole workplaces led astray by debates over
what is a repetition and how many repetitions are involved in a particular task, while the
search for common sense improvements is overlooked completely.
Probably the most common example of overkill is using the NIOSH Lifting Guide to
evaluate lifting heavy loads from the floor. If this type of lifting is routinely
done, then exceeding the guidelines is typically a foregone conclusion, and there is no
need to do a formal analysis (unless you need to prove to somebody that there is a
problem).
A good job analysis can be quite simple and yet provide good insight and into issues
and potential improvements. Some of my best success stories have come during instances
where we did virtually no formal study
— no thick reports,
no numbers, and very little on paper. For instance, some of the best improvements in the
meatpacking industry came from ideas generated in brainstorming sessions — ideas such
as mechanical assists or improving heights and reaches — where it was self-evident to
all involved that the new concept was both feasible and better. "Studies"
per se were not needed; creative thinking was.
The key is to be systematic and and have a good understanding of ergonomics principles.
Analysis vs. Measurements
It is also helpful to distinguish "analysis" from "measurements."
"Analysis" simply means to separate a whole into its constituent parts. In
the context of preventing Musculoskeletal Disorders (MSDs), job analysis involves (1)
breaking down a job into its elemental steps, and (2) identifying
MSD risk factors while
(3) focusing on separate parts of the body (neck, back, wrists, etc.).
The job analysis can be done using a checklist or even without using pen and paper at
all. Measuring risk factors and formally characterizing jobs may not be necessary.
Rigorous Methods
While keeping in mind that the typical need in most workplaces is to focus on low-tech
problem-solving, it is equally important to emphasize that more rigorous analytic tools
can provide great value in their place. Examples of these needs are:
Cost-Saving Distinctions
I f you approach job analysis in the wrong way, it could end up costing more than it's
worth. It is crucial to be clear on your goals, since the choice of the type of task
analysis to be used can vary.
In most workplaces, solving problems is the primary goal, in which case low-tech,
common sense approach is often sufficient. However, when more rigor is needed, more
sophisticated analytic tools can provide great value.
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A Low-Tech Process for
Solving Problems
The step of problem solving is commonly left out of most descriptions of ergonomics
task analysis. One useful approach is:
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For more background materials on task analysis, including copies of various types of
worksheets and checklists, see
The Ergonomics Kit for General Industry and/or The
Office Ergonomics Kit.
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