The domino effect on human error

An incident occurred today which illustrated beautifully several key points about the way business organizations generally work. It involved a small shredder I have in my office.

My wife wanted to shred a lot of documents which would have taken some time so instead of standing in my office for half an hour feeding in the paper, she decided to unplug the shredder and take it downstairs where she could watch television whilst she used it.

During the next hour or two we had workmen in the house installing loft insulation. The loft entry point was accessed through my office. After the workmen had gone my wife came sheepishly into the office and in a tearful tone of voice started rambling on about buying me another shredder.

Key point one; she was trying to confess something to me about something she had done that had made something go wrong. She was fearful of my response and so had difficulty in communicating the problem. Eventually I got it out of her that she assumed the shredder was jammed or something because it didn’t work anymore. I went downstairs and assessed the situation. The waste basket of the shredder was empty so I guessed she had recently emptied it. Sure enough, on closer inspection she had replaced the machine part of the shredder the wrong way round on the basket – a configuration which still allowed it to fit perfectly. I removed the machine head and replaced it the opposite way around. On testing the machine again the shredder worked.

“How did you do that!” my wife exclaimed. I told her there was a safety lug on the basket which has to connect with a lever on the machine head. If it didn’t connect, the machine didn’t work. On further experimentation with the device I discovered that the auto function wasn’t working. This is another safety feature where the inserted paper pushes an on switch to start the blades. Once the paper has passed through, the blades stop rotating. But now the auto function had the blades rotating permanently. “What’s happened here?” I asked.

On discovering that the machine was at least working again after a simple fix, my wife then volunteered more information which had been missing from her earlier confession.

In an attempt to get it working again she had taken the machine head apart to look for the imagined jammed paper. As she did so, some part fell out which she couldn’t identify and which she hadn’t bothered to put back.

Key point two; she had assumed several things here and when none of the assumptions had produced the desired result she had tried a workaround which simply made the situation worse. When I asked her why she simply hadn’t come into the office and asked me why it was no longer working, she replied, “because workmen were there.”

Key point three; when the comfort zone is disturbed people act unpredictably and irrationally.

I told my wife to take the machine head apart again and replace the part which had fallen out (I hadn’t done the attempted repair, so I didn’t know what I was looking for). I went back to the office.

Ten minutes later I return to the living room and my wife is in tears with the machine head in pieces. She had been unable to reinstate the missing part. Annoyed, I have to take over the repair and try to figure out where this piece of plastic belongs. Eventually I manage to work out where it fits and after several minutes of cursing and fiddling about, I manage to reseat the mechanism and get the lid back on. I tell my wife in no uncertain terms never to jump to conclusions again and never to try and fix anything herself again.

As I am having my lunch, she comes into the kitchen and tearfully attempts to defend herself – she was only trying to fix it, didn’t want to disturb me, thought it was a paper jam, thought it would be just like a vacuum cleaner etc. I admonished her for making assumptions (I have a keynote speech about ‘Assuming nothing’) and for missing the most obvious first course of action – asking me why it wasn’t working any more. It was my piece of equipment after all, therefore I would most likely have read the instructions and so would have that vital bit of knowledge about the safety feature.

Key point four; as I was telling her this I realized that the machine had a design fault. The machine head fitted perfectly onto the waste basket when it was replaced incorrectly thereby giving the impression that it was as it was before. There should have been another lug on the waste basket which prevented the machine head from sitting properly if it was incorrectly replaced thereby alerting the operator that they were doing something wrong.

Key point five (and the most crucial); my wife had been afraid of my reaction and my reaction confirmed her fears. I had simply been annoyed at her news and had to fix the shredder myself. As I was having lunch I realized this was exactly the sort of response which produced inappropriate workarounds and stifled innovation in industry. I should have been sympathetic in my response, congratulated her on her initiative and innovation in trying to fix the problem herself and thanked her in flagging up;
i) deficiencies in the product design
ii) the need for staff training regarding the operation of various pieces of equipment and the procedure to follow in case of failure.

Now I like to think of myself as an enlightened liberal who teaches about these things but it was still incredibly hard for me not to react in the way that I did, so how much harder must it be for unenlightened line managers or business leaders? I also remembered that I had been forewarned of this problem nearly a year ago. My wife wanted to shred a few documents and asked me how to use the device. I quickly went through the button positions and told her not to put a certain thickness of paper through. The basket was nearly full at this point. I had gone out on an errand and on my return I noticed the basket was now empty; she must have emptied it as a courtesy. Several days later I wanted to shred a document and discovered the machine wasn’t working. I started to check the obvious things – was it plugged in etc? when I remembered my wife had been the last person to use it and that she had emptied it. I then remembered that the basket had a safety mechanism.

Sure enough, when I checked, she had replaced the basket the wrong way round for the lug to engage. So I discovered then the possibility of this happening if an operator didn’t know of the existence of this lug. She must have emptied the basket when she had finished with the device and not used it again. Had she done so, she would have been alerted to her mistake. I should have made the effort then to tell her what she had done so that future failings did not occur.

A simple oversight on my part led to a situation where compounding assumptions and workarounds resulted in a catastrophe. Okay, this was a shredder with a happy ending, but how many stories have you heard where an airline or ferry was involved in just such a scenario and ultimately hundreds of lives were lost due to human error? It doesn’t take much.

The most valuable lesson I got from all of this was the realization that most of industry is organized around the fear of failure. Imagine how much better and happier we would all be if industry was organized around the joy of improvement and innovation.

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