In approximating costs, the estimator considers the possible causes ofvariation of the cost estimates, including（）

On some projects, especially ones of smaller scope, activity sequencing, activity resource estimating, activity duration estimating, and（）are so tightly linkedthat they are viewed as a single process that can be performed by a person over a relatively short period of time.

Project（）Management includes the processes required to ensure that theproj ect includes all the work required, and only the work required, to complete the project successfully.

In the project management context（）includes characteristics of unification,consolidation, articulation, and integrative actions that are crucial to project completion,successfully meeting customer and other stakeholder requirements, and managing expectations.