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5 WHY Analysis – Simple or Simplistic?

A blog by Alan Smith

5 minutes

Having now enjoyed over 10 years teaching Incident Investigation and Root Cause Analysis around the globe across multiple industries there are some predictable trends that emerge in the now virtual classroom.

The first is that most investigators want a system that is simple at the point of use. No one has time to get bogged down running investigations in tandem with the day job and if you use a complex model only every now and then learning fade kicks in. So keep it simple.

Secondly, I regularly meet investigators who simply want to get to that single root cause. What is that silver bullet that caused the system to fail or the worker to get injured…keep it simple

Thirdly, if it’s a low consequence incident, as thankfully most are, why would you need anything other than a quick and easy methodology to confirm what you probably already know. Again, keep it simple

So, if that’s the challenge what does a simple RCA process look like…??

Very early in my RCA education I was introduced to the 5 WHY process. The concept is simple and was a product of the Japanese car manufacturing company Toyota who still deploy 5 WHY analysis as a problem-solving technique

“The basis of Toyota’s scientific approach is to ask why five times whenever we find a problem … By repeating why five times, the nature of the problem as well as its solution becomes clear.

So… through a linear cause and effect analysis is it really as simple as that?

The first example of a 5 WHY analysis I encountered concerned what was literally a monumental issue…the problem statement was:

Why is one of the monuments in Washington D.C. deteriorating at an accelerated rate?

Why Q1 – Why is the monument surface deteriorating?  

•  Because harsh chemicals are frequently used to clean the monument.

Why Q2 – Why are harsh chemicals needed?

•  To clean off the large number of bird droppings on the monument.

Why Q3 – Why are there a large number of bird droppings on the monument?

•  Because the large population of spiders in and around the monument are a food source to the local birds

Why Q4 – Why is there a large population of spiders in and around the monument?

•  Because vast swarms of insects, on which the spiders feed, are drawn to the monument at dusk.

Why Q5 – Why are swarms of insects drawn to the monument at dusk?

•  Because the lighting of the monument in the evening attracts the local insects.

Solution:  Change how the monument is illuminated in the evening to prevent attraction of swarming insects.

On the surface, this seems impressive indeed persuasive however the simplicity of this with a single root cause has well and truly been de-bunked.

In reality, the report from a subsequent consultancy investigation, cited the use of chemicals as a contributory factor but one only one of many others including acid rain, water seepage, air pollution and littering tourists.

So, in essence, the 5 WHY outcome wasn’t incorrect but importantly it wasn’t the complete solution and therein lies the risk. It provides a one-dimensional view of a multi-dimensional issue.

Ironically, the recommended solution of delaying the illumination of the monument at dusk did get piloted for 6 weeks but the original times were then reinstated due to complaints from the public that iconic photographic opportunities of the monument at dusk were being lost! Implementing solutions is a tough business!

The risks with applying 5 WHY analysis… and I`ve seen many poor examples can be summed up as follows in 3 simple statements:

1)  It delivers only a single root cause where this is almost never the case

2)  The answer to each why is constrained by the knowledge of the investigator..which is frequently lacking

3)  Following an unstructured undisciplined process easily allows the investigator to fall victim to reaching the preferred conclusion. This is called confirmation bias.

So, to circle back to my original problem statement…how can we help investigators analyse incidents in a

·  Time and resource efficient manner that

·  Uncovers consistent and reliable root causes

·  Across the complete spectrum of the incident?

The answer I believe is COMET Lite which is our solution to high volume low consequence incidents and in three short steps, absolutely addresses the analysis risks we have covered.

Step 1 Discovery - Using the COMET taxonomy, the investigator is guided to consider data across the full spectrum of root cause categories…a simple Q & A process that typically takes 20 – 30 mins considering

Communication – Written and verbal

Operating Environment – Individual, Task related and organisational Human Factors

Management – Supervision, Risk Assessment and Organisational learning

Equipment – Pre and post operation of equipment, plant and technology

Training – Competence assurance

Step 2 Analysis Take the problem statement in tandem with the data gathered at Discovery and run this through the abbreviated COMET Rootmaps to identify the Root Causes (plural!) that conspired to create the ingredients for the incident

Step 3 Action – Make use of the COMET Preventive Action Prompts to develop proportionate but powerful actions to prevent repeat failure

Typically, the COMET Lite process takes around an hour, which is probably 5 times longer than a 5 WHY but easily 5 times as powerful. In effect simple not simplistic!

The adjective simple means plain, easy, ordinary, or uncomplicated (COMET Lite).... The adjective simplistic is a pejorative word meaning overly simplified that is, characterised by extreme and often misleading simplicity (5 WHY)

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