5 whys have been introduced here already, but I wanted to expand on it briefly, cover a few of its pitfalls and give you a tip on how to 5-Why TURBOCHARGE.
As a quick summary, 5 Whys is essentially asking the question “Why” a number of times, expanding on the answer on each iteration. In this way the root cause of a problem will eventually be revealed. The magic number of question levels tends to be five. After five, there will likely be found a missing process or an action item, or some unmitigatable (okay, that’s not a word) natural force – like “gravity”.
Beyond that, it is a vehicle for investigation. There is no substitute for careful, fact-rich, investigation.
Benefits:
- Low barrier to understanding and use
- Introduces the concept of disciplined problem solving
- Helps avoid the “Hammer = Nail” effect; the tendency to apply a known solution to an unknown problem.
Drawbacks or criticisms:
- Tends not to be data-driven
- Answers are particularly subject to cognitive bias
- Stymied by multiple-cause situations
- Often the only tool used
Let’s look at these in turn:
Tends not to be data-driven. This is the 5 Why’s double-edged sword. Because it isn’t data driven it is easier to adopt and use; the learning curve is approachable. However, without data the conclusions are often not repeatable, especially when the problem is complicated. Generally, this isn’t a big problem, but it is something to be aware of.
Answers are particularly subject to cognitive bias. What is a cognitive bias? These are shortcuts the mind uses due to numerous factors such as the human brain’s processing limits, emotional and moral motivations or societal influences. Consider the audiences of Fox News versus MSNBC – the respective audiences tend to watch only one or the other, depending on what their political view is. This type of cognitive bias is called “Confirmation Bias” – interpreting data to fortify existing views.
Cognitive biases, while hugely interesting as a field of study, are very powerful and part of what makes us human – but they can often lead to incorrect conclusions. This drawback is linked to the lack of data used with this tool. Much of the mental process is “off the cuff” – especially if the investigations are weak. Again, something to be aware of.
Stymied by multiple-cause situations. 5 Whys seeks to find a single cause, that is what it does. Be aware that there may be other factors at work.
Often the only tool used. There are many other tools that can be used – fishbone (Ishikawa Diagrams), 8Ds, Design of Experiments, House of Quality, cause-effect diagrams, FMEAs. I won’t explain these now, but there are these and more. With all of these available, it’s a shame to use just the one.
5 Whys – Turbo Charged
How to get a little more out of 5 Whys, once you feel the technique has been mastered.
For each “WHY” answer, consider in what way it could have been detected, and what could be done to prevent this particular why. Once a cause has been determined, review those countermeasures and decide how to implement them, or a selection of them.
Example:
Problem: Delivery trucks are late 60% of the time.
1 Why are they late? Interviews with drivers reveal they sometimes get lost en route.
2 Why do they get lost? Unfamiliar with territory.
3 Why are they unfamiliar with the territory? New hires, new to area.
4 Why don’t the new hires know the area? They haven’t been shown.
5 Why haven’t the new hires been shown? Never needed to be; expanded business has led to the hire of several new drivers.
As you review each of these, you should allow yourself to get a sense of the arbitrary nature of some of the answers. Again, this is a feature of 5-Whys and no reason to avoid using it.
Now, the turbocharging comes into play like this:
1 Why are they late? Interviews with drivers reveal they sometimes get lost en route.
HOW COULD THIS HAVE BEEN DETECTED and/or PREVENTED [SOONER]?
- Provide a means for drivers to communicate with HQ when they are running late.
- Determine a “comfort zone” for timeliness
- Escalate awareness of late deliveries
2 Why do they get lost? Unfamiliar with territory.
HOW COULD THIS HAVE BEEN DETECTED and/or PREVENTED [SOONER]?
- Communication path (as above)
- Provide GPS devices
3 Why are they unfamiliar with the territory? New hires, new to area.
HOW COULD THIS HAVE BEEN DETECTED and/or PREVENTED [SOONER]?
- Place hiring preference on local inhabitants
You probably get the idea here. Real-world problems may have more sensible details, but the lesson is the same. For each why, determine what could detect or prevent it.
From the exercise above, it could be that the company chooses a few, or all of the countermeasures determined. Flexibility is key.
Having said all this, please do remember that adding inspections, or detection layers without modifying the process to eliminate their need is a recipe for failure. Always strive to create a process whereby failure is not an option.
So. 5 Whys; a nice, easy to wield tool – but has some limitations mostly because of it’s simplicity.
Thanks again for your time and attention. Go forth – Why? to calibrate thyself, of course.
Sal