There’s an interesting post on Open Loops about the pitfalls of accurately-estimating project durations – and specifically the problem of over-optimistic schedules:
Many project managers can be myopic in this area and not see the potential pot holes in the road ahead of their projects. Being aware of these stumbling blocks and developing a system to accurately project deadlines can bring projects in on time and underbudget.
The technique is an interesting mix of mindmapping and focussing on next actions – in other words, ensuring that you’ve got a realistic and robust work breakdown structure – as well as a formulaic calculation. It’s not clear whether the formula is a rule-of-thumb or has been derived from data, but it’s probably a useful starting point.
I’m always a little wary of formulas – when there’s a calculation to come up with an answer, there’s always a temptation to rely on this as a definitive God-given answer that has to be correct to five decimal places – but if people are involved as a factor, there’s a danger that you’re lucky if the answers are accurate to an order of magnitude.
Nevertheless, it’s a good technique for creating quick-and-dirty “straw men” for planning purposes, and the breakdown steps are a good way of approaching the planning process.
