I’m currently working with a major airline. Over the weekend there was an issue where one of the hanger doors wouldn’t open & the technical team had to jump through quite a few hoops to get the aircraft out for the flight schedule the next day. On Monday those responsible for the hanger building, including the doors, were able to determine the cause for the failure. The battery had died because the charger had stopped working.
Today they replaced the charger. Problem solved! Or not. This is a typical solution to a problem of this sort and they happen in pretty much any organisation. Part fails, replace the part, everyone’s happy. The problem with this level of solution, is it is treating the symptom, not the root cause. The battery failed because the charger failed, but why did the charger fail? More importantly, while we may think the problem is solved, the fact is the problem remains as this could happen again tonight, tomorrow or more likely, several months from now, or possibly years.
The risk is still there – so we need to get to the root cause of the problem, not the fact that the charger failed, but why did it fail? Overuse? Lack of maintenance? Worn out? Beyond useful life? Etc. Whichever the cause, there is always a solution to the problem, we just need to determine if the cost of the solution is more than the cost of future failures?
So we start with understanding the cost of future failure, both in terms of time lost or wasted but also the risk to missing flights (in this case). It may be that we are happy to allow this failure again and to have the people on shift jump through hoops again to deal with it when it does. It may also be that we definitely do not want this to happen again. The cost of failure should help us in making this determination.
Once we know the cost, we should then determine the cost to ensure it doesn’t happen again. This obviously depends on the solution, which of course depends on the root cause. Was there a system in place to check or verify the operation of the chargers – what is the standard? Did the standard fail? Was it not followed? Or did it exist? In this case there is no standard, there is (or was) no expectation that one of the chargers may fail. Now that we know they will (and of course an FMEA in advance could have determined this risk), what can we do about it. Is there a solution to remove the risk of failure that will cost less than the cost of the failure?
There are many options for solutions, replacement of components at set intervals, inspections, indicators (lights for example), etc. In this case most would be relatively inexpensive, but does the cost of the solution outweigh the cost of failure? Whatever the case may be, whatever is decided, as long as it is clear, that becomes the standard, the expectation. we either ensure it doesn’t fail again, or we create a standard for how to deal with it when it does. Then the problem is solved.