Estimating is perhaps the most basic element of any project, but also has the most profound impact on whether the effort begins well or is doomed to face consistent set-backs and missed opportunities. As Susanne Madsen writes in her blog post, it’s perfectly natural to create underestimated projects (after all, who doesn’t want to complete work quickly and efficiently), but being unrealistic in estimates helps nobody. With that in mind, Madsen writes 10 guidelines to help estimate project effort more accurately, starting with this tip:
Bear in mind that estimation is an ongoing activity which should take place regularly throughout the project. In the initial stage a high level estimate may be required in order to determine the feasibility of a project, whereas later, a more thorough analysis and estimate would take place, which is then gradually refined. Having said that, always resist the temptation to provide an estimate without having any detailed requirements or analysis to back it up. If senior management needs a quick indication of potential costs in connection with an initiative, provide them with a “best guess” and make sure they don’t take it as an official estimate.
She goes on to explain that breaking down requirements into individual sections can help you understand scope, involving experienced people in the analysis and estimation process as well as the people who will be performing the work helps create a more accurate estimate, and how to estimate honestly (that is, don’t just make estimates that assume best case). Susanne’s advice is practical and immediately useful. One of the most useful comes at the end: document your estimates and how you arrived at them. There is much more value in realizing 6 months later how you came to a faulty estimate than just recognizing that it was simply “bad.”