Some time ago I read the c++ timeline explained [1] and this part stuck with me;<p>"You can fix a feature list, or you can fix a date, but not both."<p>When doing estimates now I use the above mantra a lot.<p>Usually I pick a date for incremental updates. I find that more useful to people. But people asking before that date "what's in it?" seem somewhat bemused when I say '"I don't know".<p>For new projects we're more likely to pick a minimal feature set, but that causes some stress up the management chain who can see "progress" but can't yet see a finishing line.<p>[1]<a href="https://herbsutter.com/2019/07/13/draft-faq-why-does-the-c-standard-ship-every-three-years/" rel="nofollow">https://herbsutter.com/2019/07/13/draft-faq-why-does-the-c-s...</a>
My experience isn't that estimates are impossible or unreliable, even with somewhat novel work. Most of the problems come from a lack of respect and understanding for the estimates and for who is making the estimates.<p>Back in 2019, I estimated a project to move a product to the cloud so that we could scale it out and make it more reliable. The business was projecting big growth, the existing system required daily baby sitting, and there were features that just didn't work because of poor software engineering. At the time, I barely had any cloud experience, hadn't used Python/R/Docker for very long, and didn't understand the product or business in depth. And yet, I was the most knowledgeable person on the team.<p>I estimated the project would take me 2 years. The project manager didn't like that. Behind closed doors they talked to my manager who told them 6 months was fine. They didn't talk to me about the team, the scope, the approach, nothing. The project got the green light and I was given 2 fresh grads - one who was awesome and one who wasn't.<p>Cut to a year later and we're spot-on my estimate, half way. We've delivered the major features and stabilized the product. It scales perfectly and is far below operational budget. Yet people are angry because it was sold as a 6 month project to middle management. The product was worth $10s of millions annually to the company. They're fretting over a couple $100k that they would have spent anyway.<p>But they didn't respect me or understand why it was 2 years. They could have talked to me about alternative approaches (maybe a lift and shift but I was strongly opposed). They could have asked me what sort of team could have done it faster (4 senior, motivated, knowledgeable, responsible engineers).