What is Bottom- up Estimating?

Bottom-up estimation is similar to assembling a large puzzle by breaking it down into smaller pieces. Assume you’re constructing a massive Lego castle. Rather of predicting how many pieces you’ll need for the entire castle at once, you start by estimating how many bricks you’ll need for each section—walls, towers, and roofs—and then add those figures together to obtain the total. Bottom-up estimating works similarly for projects: you figure out the specifics and expenses of smaller elements first, such as individual jobs or components, and then sum them all up to obtain the total budget or timeframe for the entire project. It’s like taking baby steps to grasp the full picture.