Overview:
Perform ongoing tasks that are not necessarily part of the project schedule.

Main Description:

This activity includes a single task, Request Change. This task may occur any time during the lifecycle in response to an observed defect, a desired enhancement, or a change request. It is not planned, which means that it does not appear as a scheduled activity on the project plan, iteration plan, or work items list. Nevertheless, it is a critical activity that must be performed to ensure project success, because your environment is not static.

Any Role may perform this task, however the most common sources of Change Requests are Stakeholders (enhancement requests and change requests) and Testers (defect reports).