What does it mean “Top down or bottom up estimation”?

Hi Bervivez

Top-down estimating occurs when company management imposes a cost and/or duration on a project, usually without a detailed cost analysis.

Thanks man!

Top down estimation is when you look at the current market size as a whole, for example, if I were to determined the top down market size estimation of Uber, it will be all people in the world with access to a smart phone and a credit card.

Then bottom up, is when you narrow it down to calculate the actual potential size of the market you could acquire.