Estimating activity durations uses information on activity scope of（），required resource types, estimated resource quantities, and resource calendars.

Project work packages are typically decomposed into smaller components called activities to provide a basis for（）scheduling, executing, and monitoring and controllingthe proj ect work.

Define Activities is the process ofidentifying the specific actions to be performed toproduce the（）

During the project, requirements change for a variety of reasons. As needs change and as work proceeds, additional requirements are derived and changes may have to be made to the existing requirements. It is essential to manage these additions and changes efficiently and effectively. To effectively analyze the impact of the changes, it is necessary that the source of each requirement is known and the rationale for any change is documented. The project manager may, however, want to track appropriate measures of requirements volatility to judge whether new or revised（）are necessary.