I recently read an article on the PMI website about bad estimates and project cost overruns. The article was by Dr. .James T. Brown. Dr. Brown talks briefly about the typical political and personal pressures that cause failed estimates. However, one of the more interesting items listed in the article is recent Oxford Review on Economic Policy. The review studies infrastructure estimates and has a comparative graph showing road/bridge type projects vs. IT projects. Guess which one is more commonly underestimated? Here is a link to the article… http://www.pmi.org/en/Knowledge-Center/What-Causes-Bad-Estimates.aspx
One Reply to “The Common Error in Estimating Projects”
What a gold mine this article is! This sentence really rang true for me: “Factor one is insufficient time to deal with uncertainty in the estimating process.”
People are rarely good at estimating time. They are even worse at estimating the time it takes to estimate time. In other words, it takes a good deal of time to figure out how long something will take to do. Unless you take time to figure things out, you won’t be able to estimate how long it will take to implement them.
This is the biggest reason I like “micro releases.” Small, foundational, incremental change is easiest to estimate. Big, deep dives are hard.