Seven Lessons in How Not to Do An Upgrade

The science fiction series <a href="https://tv.apple.com/us/show/silo/umc.cmc.3yksgc857px0k0rqe5zd4jice" rel="noopener ugc nofollow" target="_blank">Silo on Apple TV+</a> is an adaptation of <a href="https://bookshop.org/p/books/the-silo-saga-wool-shift-dust-and-sil0-stories-hugh-howey/14520864" rel="noopener ugc nofollow" target="_blank">Hugh Howey’s series of Wool books</a>. While the enemy in the series is a shadowy government that hides secrets, <a href="https://tv.apple.com/us/episode/machines/umc.cmc.4qn04sxn1o6qdazlw79gxe4bz" rel="noopener ugc nofollow" target="_blank">Season 1, Episode 3</a> of the series featured something frightening to many software development and IT professionals: An emergency hardware upgrade with minimal forethought, lack of contingency plans, arbitrary deadlines imposed by upper management, and inadequate communication to users. Here’s a breakdown of what Juliette and her team did, and what real-world professionals can learn not to do. While the episode features a repair to an electrical generator, the problems and perils apply to both hardware and software upgrades in the real world. <h2>1. Juliette had a bus factor of one.</h2> The titular Silo is a massive underground structure with hundreds of levels where 10,000 people live sealed off from the outside world. Electricity for the entire Silo comes from a generator at the lowest levels. Engineer Juliette, the series’ hero, is the only one who understands the day-to-day behavior of the generator. Fortunately, she is in the process of training someone as her “shadow,” so it’s not all bad. In the real world, we would say Juliette has a bus factor of one. The bus factor is based on the idea that it is a risk to have few people with critical knowledge, and if one of those people leaves a team (“gets hit by a bus”), the team loses that knowledge. Often when someone gives their notice at a job, the boss will have the departing employee “write down everything you know.” This solution is laughably inadequate as anyone who has tried to take over in a such a situation will attest. <a href="https://medium.com/pragmatic-programmers/silo-3724446c0438">Website</a>