A misunderstanding of statistics might be a huge part of why projects are alway late at your company.
we found that setting simplistic timelines – adding up median completion times for each step in your project – consistently underestimated how long projects would take. In fact, creating a timeline based on median completion times underestimates the actual project timeline 67% of the time.
For every step in a project, there’s about a 50% chance of completion under or on the median step completion time. And there’s about a 50% chance of not. … If a project has 6 steps, the chances of some of those steps going over its median is greater than 98%. … But while there’s a lower bound to how “under” the median a step can be – a step can’t take negative time – there’s virtually no upper limit to how much over the median time a project can take.
