Oops, I Did It Again*
Embracing mistakes as vital learning opportunities in engineering practice.
Original Publish Date: August 2018
Updated: November 4, 2025
Author: Andy Pearson - PH.D., C.ENG.
Download Original Article Here
When I was a young engineer, not long started in the refrigeration industry, I received a memo from my boss. It said “You are hereby authorized to make two big mistakes per year, otherwise you will never learn anything.”
He told me the story of an old design engineer who had visited a site just as a plant was being commissioned. He was asked to flick the switch to turn the compressor on, but despite having been involved in the project from day one, knowing the design back to front and having personally checked all aspects of the installation, he was unable to do it. The old engineer confessed that he had never actually taken that final step before and he was too nervous to do so.
The point of the memo was to encourage a certain degree of adventurism, without which any business enterprise will gradually stagnate and eventually die. It worked, but I have to say the mistakes were not glorious learning experiences in the heroic traditions of the best “battle against adversity” Hollywood movies. They were toe-curling embarrassments.
On one occasion as a sales engineer I was sizing a compressor for a chiller project. The project was for a petrochemical site with water being cooled from 25°C to 7°C (77°F to 44.6°F). I happily subtracted 7 from 25 in my head but for some reason got the answer “13.” As a result, I selected a six cylinder compressor for the job and the mistake wasn’t discovered until we had received a purchase order and were committed to a price. Ground, swallow me up! That model of compressor was also available in a 10 cylinder version and we were able to make the chiller work, but at a significant cost.
Another time, when I was supervising the construction of an ice bunker on site as an extension of an existing flake ice system we had gotten all the way to the point where the bunker was built, the steel frames to support the four ice machines were installed and it was the day before the ice machines arrived along with the 300 ton crane required to lift them onto the roof of the building. It was only when the design manager arrived to review our state of readiness that he realized that, while the roof of the building had been extended at the same height as the existing building, the new bunker was about 2 ft (610 mm) taller than the old one. As a result there wasn’t enough headroom for the ice machines, which were due on site the next morning. A frantic dash back to the design office that evening produced a revised support arrangement with the secondary support steels slung under the main beams, gaining just enough room for the ice makers. It wasn’t pretty, but it worked.
Perhaps the best lesson I learned from these blunders and many, many more was that it is good to learn from your mistakes but it is even better to learn from someone else’s. That’s why I take a great interest in news of accidents and near misses from around the world; there is always scope for us to improve what we are doing to reduce the chance of it happening to us. Even so, I think that I fell slightly short of the memo’s target of “two big mistakes per year,” although I probably make up for it with the almost daily stream of smaller ones.