By its very nature, estimation is a game of unknowns. When we make projections for budgets, revenue or returns, we base them on a series of wobbly assumptions. Each assumption in itself might be somewhat reasonable, but the more of them we put together, the shakier the foundation is on which we build our estimate… and the more likely the estimate is to collapse in a heap.
The fact that we base so much of our decision-making on these estimates ought to be worrisome, when we consider how they’re actually built in the first place.