Answers:
The bottom-up approach is also known as definitive estimate or micro estimates. It is an approach used for estimating the cost, time, and risk involved in a project, which help in preparing a more realistic budget. Though, it is time consuming, it is the most accurate estimation approach. It would help to introduce the term WBS (Work Breakdown Structure), which is defined as a deliverable oriented hierarchical breakdown of the entire project scope. Various standard analytical tools, such as learning curve analysis and work sampling are used in this approach. The estimates for resources are first made in terms of labour hours, materials and then converted into monetary equivalents.