Some people like developers to estimate in story points based on complexity, some on estimated number of days.<p>Managers or whoever asks for things to be estimated wants to establish team velocity so they get to know how long things take and how to plan accordingly.<p>What do people think of 'estimations' especially faced with developer uncertainty and the potential overhead associated with the 'act' of estimating things you haven't even started on
My main criticism with pointing based on complexity is that people don't think in complexity, they think in time. For example, a 1 point ticket might be to move a 50lb weight up a flight of stairs. A 5 point ticket might be to move a 500lb up a flight of stairs. If you plan a sprint with 2 developers taking 5 points each, one with 5 of the 1 point tickets described above, and the other with a single 5 point ticket described above, you lose the complexity dimension. 5 points vs 5 points looks like apples to apples, but it is really 5 apples vs 5 oranges.