Channel your inner two-year-old

Need to catch up? You can read the entire series on RCA here.

At this point of RCA, you should be looking at a diagram filled with possible causes. But you're not done yet: this first pass of brainstorming tends to yield physical and human causes; in order to get to the top-secret causes, you need to dig into each of the causes you've identified thus far.

If you've ever parented a toddler, spent time with a toddler, or been a toddler, you'll know that the period known as "the Terrible Twos" is defined, at least in part, by what seems like constant curiosity. Annoying though it can be, the average toddler's tendency to ask "why" until your ears bleed is a habit you'll want to borrow in this phase of root cause analysis.

This technique is referred to as the Five Whys. Don't be misled - five is not a hard and fast number here; you might need to ask more than five times (or fewer). The point is to continue asking why until you get to what's really driving that particular cause. For example: you're analyzing an overshipment of widgets; among the possible causes is "Customer Service Rep mis-keyed the order quantity." Your mission, should you choose to accept it, is to figure out why.

So, why did the CSR mis-key the order? Because s/he thought the order was for 10 cases, when it fact it was for 10 eaches.

Why did the CSR think that the order was for 10 cases instead of eaches? Because the customer didn't specify the unit of measure on the order form he submitted.

Why didn't the customer specify the unit of measure? Because the order form in place doesn't have a space to enter unit of measure.

Why doesn't the current order form ask for unit of measure? Because it's an old form from our previous system (which used only one unit of measure for ordering), and the form hasn't been updated.

Why hasn't the form been updated? Because updating the order form is not considered a high priority.

Why isn't updating the order form a high priority? Because everyone knows that we have to specify the unit of measure in the order entry system, or all orders will default to case unit of measure.

Okay, so that took six whys, but we got to the top-secret cause, didn't we? If we can convince ourselves that "everyone" knows that they must specify the unit of measure (and apparently, that's exactly what we've done), then we don't need to go to the trouble of updating a form. These types of assumptions drive more business inaction than you might think - and consequently cause more problems than you might think.

If you want to take the Five Whys to a deeper level, you can use the Five-by-Five Whys. I find the Five-by-Five Whys to be a terrific tool in RCA, because they can help you both identify latent causes and filter your list of causes as you go, thereby helping the process move a little more quickly.