>In short, this bias leads planners to view their projects as unique, thereby disregarding valuable lessons from previous similar projects. I once had a discus

>In short, this bias leads planners to view their projects as unique, thereby disregarding valuable lessons from previous similar projects. I once had a discussion. We had some managers that would systematically over or underestimate their projects, mostly underestimate. I suggested that we take into account the estimation accuracy of previous projects for that manager and adjust their estimate. They said that each project is too unique to do this. But I saw the same optimism or pessimism playing out repeatedly for the same managers when looking at the numbers. Although tbf I think accurate estimation can be bad if the person managing the project knows about the estimation. Since if they have more time, there's less pressure, and they'll have overruns again, making the estimation inaccurate again. Hofstadter's law, to me, is less about accurate estimation and more about human psychology. If you know you have more time, you waste more time. This is also a failure-mode in agile project management. If you don't have strict deadlines, it's easy to fall into infinite iteration, because there's always something that could be done better.