Last week in Part I of this blog, we offered the story of a car that wouldn’t start every time its owner bought vanilla ice cream. In short, the man complained to the company that every time he went to the store to buy vanilla ice cream, he got back in his car to find that it wouldn’t start. Yet, whenever he got any other flavor, the car would start just fine.

So, why wouldn’t the car start?

Resolution, using a KT Clear Thinking approach

When solving any problem, first we need to understand the nature of the problem. In this case “Car doesn’t start” is a “What did change?” problem. Sometimes the car starts fine, and sometimes it doesn’t. So, something changes and we need to identify that specific change.

To accomplish this we will follow an exclusive approach which is a method that rules out false causes and points us to true cause as quickly as possible. So, what do we know about this situation that will allow us to rule out incorrect theories and guide our search for the true cause of the problem?

First, we know what it is that has the problem, in this case it is the car itself, and the car has both good and bad trips. Because it is unlikely the car itself changes consistently between good and bad trips, we can exclude this from our search for change.

Second, we know where the problem is observed, in this case it is at the store and, the store is the site of both good trips and bad trips. Again, it is unlikely that the store is changing consistently between good and bad trips, so we can also exclude this from our analysis.

Finally, we know when the problem is observed, in this case it is only during trips to buy vanilla ice cream. Trips to buy all other flavors are fine. So the key question is "what is different about buying vanilla ice cream when compared to buying other flavors?"

Through his investigation, the engineer learned that vanilla ice cream, because it was the most popular flavor, was sold in a separate case at the front of the store for quick pickup. All the other flavors were kept in the back of the store at a different counter where it took considerably longer to find the flavor and get checked out. So, trips to buy vanilla took less time than trips to buy all other flavors.

Mystery Solved

The engineer used this new information, together with his knowledge and experience of automobile engines, to develop the hypothesis that the reason or, the cause of the car not starting was a vapor lock. The vapor lock was a constant condition in the car, but on the nights when the man bought other flavors the extra time required allowed the engine to cool down sufficiently to start. When the man got vanilla, the engine was still too hot for the vapor lock to have dissipated and so, the car would not start.

The KT Clear Thinking process allows for rapid resolution of sticky and complicated issues. The “moral” of this story is that buying vanilla ice cream and the car failing to start are correlated events however; this story demonstrates that correlation does not mean causation.  This often is the case in work environments. This story displays key factors used in the KT Clear Thinking process which save work teams and organizations time and dollars. We hope you enjoyed this demonstration, a logical fallacy, and its resolution. 

Read the story Help! My car is allergic to vanilla ice cream in its entirety.

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KT has a powerful toolkit for root cause analysis and preventing future problems.