Years ago, I was managing the sale of a business division. The business was based on carrying out a highly-specialised technical test on clients’ products, and each time a test was carried out, it made a loud bang. This would have been of no concern if it had not been that they were carried out in a large workshop also used for other activities. However, checks had been made and the noise levels were within legal safety limits. Just before signing the deal, we happened to mention to the purchaser that we had some tests scheduled for the next day, and he said he’d like to send someone round to check the sound levels. It was a beautiful summer’s day – until their measurements showed that the bangs were over the limit. What a toe-curling moment! Clearly, we had made the wrong assumptions. In the end it was not as bad as it seemed: a sound-attenuating box solved the problem without making access too difficult, at quite modest cost and with only a few weeks’ delay. But the proving tests provided another surprise – the noise levels were legal again without the box. The reason – we now realised – was that the humidity of the air could affect its sound-attenuating properties.

Avoiding wrong assumptions

Conclusion 1 – Make sure you know what factors can affect your assumptions. Wrong assumptions may lead to disaster. Conclusion 2 – Don’t rely on conclusion 1! If something is critical, don’t rely on a modest safety margin – do what you can to increase it early, in case there is something you have not anticipated.