By Jeff Sipes
Does it seem like you deal with the same problems over and over? It could be a qual- ity issue, a schedule problem, a personnel
matter, or numerous other things. If this sounds
familiar, you may be dealing with symptoms, not
Every time we spend time reworking “solutions,”
we incur the waste of precious resources. It can be
frustrating and distracting. Yet until we address the
root cause, the non-value-added cycle will continue.
Root Cause Versus Symptom
It is easy to toss around the term root cause when
discussing process problems. The boss says, “I want
you to get to the root cause!” The engineer shares
her findings from her root cause analysis. The
kaizen team spends the day focused on understanding
the root cause. We frequently hear the term being
used, but rarely do we question if we are honestly
and rigorously getting to the actual root cause.
So what is a root cause, and why is it so important? Let’s start by contrasting a root cause with a
symptom. Webster’s defines symptom as “
Something that indicates the existence of something
else.” Let’s apply this in an industrial setting. Kaizen
team members look at a problem and uncover a
symptom—but that’s just the first level of analysis.
If they stop at the first level, develop and implement
a corrective action, and expect a permanent resolution, they will be disappointed when the problem
Why? The first level of analysis points to something deeper, something that provides enough
evidence to keep on analyzing. But it is easy to get
fascinated with an obvious answer to the problem
being addressed (that is, the symptom), implement
the quick solution, and then move on to the next
problem. This feels good and seems efficient. But
the elation is short-lived when the problem reoccurs. If you “fix” the symptom, then at best you have
put a Band-Aid on the wound.
The root cause is the fundamental reason the
problem occurred. Another definition describes root
cause as a factor that caused a nonconformance
and provides an opportunity for a permanent fix.
If we identify and implement a solution addressing
the root cause, the problem should not reoccur.
The absence of a root-cause focus leads to a vicious cycle that produces little or no improvement.
If we stop wasting time on symptoms and spend our
scarce resources understanding and addressing the
root causes of problems, we free up resources to
tackle more important issues.
Two techniques, the 5 Whys and the cause-and-effect diagram, can help you identify root causes.
Think of these as everyday problem-solving tools
that many people in your organization have proficiency to use … and are empowered to use.
The 5 Whys
The 5 Whys, a structured way to move from an obvious symptom to an actionable root cause, can be
done by just one person as well as by groups large
and small. All people need is a whiteboard, a flip
chart, or a piece of paper.
Start with the issue at hand, such as a machine
that does not meet the defined takt time. This is a
symptom, and at this point it is not clear what action to take.
Next, ask “Why?” five times. There is nothing
magical about the number 5, but it seems to be an
effective target to get to an actionable item. The
closer you get to the fifth “why,” the more specific
We start with, Why is the machine not meeting
the takt time? A pneumatic material pick-and-place
device is moving too slowly. The kneejerk response
would be to simply turn up the air pressure. But
would that fix the problem? No.
Instead, we ask, Why was the device moving too
slowly? There was debris in the machine’s air filter.
Again, the quick corrective action would be to clean
the air filter and start running again. But this still
does not address the root cause, because the debris
had to have come from somewhere.
As we work through the rest of the questions, the
root cause becomes clear: There was a breakdown
of the plant’s main air filter, which not only contaminated the parts-handling device, but also had the
potential to affect the plant’s entire air system. Fixing the symptoms (not meeting takt time, handler
moving too slowly, debris in the machine’s filter,
etc.) was not going to make the problem go away.
Cause and Effect
Have you found yourself in a problem-solving
meeting where there is lots of talk and little documentation? People spout ideas that are quickly
forgotten. Everybody has an opinion, and sometimes people even present some data. But it’s still
a verbal free-for-all that expends lots of energy yet
produces few results.
The cause-and-effect diagram can help by stripping away the noise and bringing structure to the
analysis. You may also know this tool as the Ishika-wa diagram or the fishbone diagram. It’s most effective when used in a small group with a facilitator.
First, decide what specific effect (that is, problem)
you want to analyze. The effect might be that you
run out of material at the pipe welding station, or
the throughput time in the pipe welding cell is 25
percent too long, but it cannot be both. One might
be related to the other, and the diagram you generate will probably show this relationship. But for this
method to be effective, you must focus on one effect, then build the diagram around it.
Next, draw the fishbone skeleton. Make a box to
the right side of the space for the effect. Draw the
main vertebra, a straight line extending from the
box across the space to the left. Add four lines with
two going up from the horizontal vertebra and two
going down. Spread the four lines out so there is
Read more from Jeff Sipes at www.thefabricator.com/author/jeff-sipes
Look past the symptom
Tackle the root cause
to put problems to bed—for good
In this illustration of the fishbone diagram, the arrow on the right points to the effect, and the four lines connecting to the vertebra cover four main topics: man, machine, materials, and methods. Lines connected to them show
the chain of cause and effect.