In an incident situation we are always looking for that “Silver Bullet” question – the one question that would bring some insight to the incident being experienced. The good news is that there is such a question; in fact there are a few of these questions that could provide you with that insight needed. We call that the “but not” question.

Asking someone what the “fault could be” under the same circumstances “but is not” is normally met with a blank stare, because they either do not understand the question or they find the question highly counter intuitive. It is surprising, because we are used to asking this question in our everyday lives. Let’s take the example of you getting home after dark and proceeding to put on the lights. When flicking the switch the light does not come on and without even thinking about it you move to the second switch to see if that one is working or not.

Why would you do that? Well, without even knowing it you are looking for a BUT NOT to the existing situation. Imagine this light did not switch on either…now you are concerned, because it now seems a bigger problem than initially thought. What do you do now? Now you are thinking of causes or reasons why this might be happening. Maybe it is a general outage or a circuit breaker that tripped. Quickly you would be looking for a BUT NOT. You look outside and see that the lights in the neighbourhood are all on and you come to the conclusion that it must be the circuit breaker. Looking at a series of BUT NOTS you “solved” the situation.

So, due to the insights created by asking BUT N OT questions and checking it out you came to a useful conclusion. We suggest the same kind of thinking in a business incident investigation situation. For instance you ask the question to a group of people “Where is this fault noticed in our operations?” You might get a fairly unsatisfactory answer such as “all over our operations”. However, if I now ask a BUT NOT question such as “Where in our operations could we expect to have this same incident, but we don’t?” We would discover information that would give us much better insight into the first answer. The staff might take some time to think about this and then agree on an answer, but they agreed that it is not happening in Hong Kong. Now that is what I call useful information!

This BUT NOT question is a powerful process question aimed at creating anomalies that needs to be explained and which is normally the underlining factor in what is causing the incident. We would suggest you ask these BUT NOT questions for all the facts that you’ve uncovered for the IDENTITY, LOCATION, TIMING, USERS, FREQUENCY and SEQUENCE information collected during your investigation. This curious contrast created between what it is and what it is not is a highly effective way to create ideas about cause.