There are seven steps that are used in project estimation management.

Assigning Estimator
Project Manager should assign a member of a project team to be the Estimator. In general, the Project Manager, Business Analyst or Product Analyst of a project can be the Estimator.

Collecting Information
Estimator should collect all available documents and information of a proposed system. [...]

A project plan consists of two main elements that effort and time form the basis for tracking the progress of a project. Project manager requires estimate these two elements as accurate as possible. Therefore, estimation management process involves an analysis of a proposed or active project to produce a forecast of the project’s effort and [...]