Which of these tasks focuses on executing the change according to the plan?

The focus of executing the change according to the plan is clearly embodied in the implementation phase. Implementation is the stage where the actual work of putting the planned changes into action takes place. During this phase, the detailed steps outlined in the planning process are carried out to ensure that the change is effectively realized in the operational environment.

This phase involves coordinating resources, processing the necessary actions, and closely following the procedures defined during planning to minimize risks and ensure success. It's critical to adhere to these predefined steps to align with broader organizational goals and maintain integrity in the service management lifecycle.

Other tasks, while important in the overall change management process, do not pertain to the execution itself. For instance, reviewing involves assessing the change post-implementation to evaluate its success and gather insights. Planning refers to the preparatory steps that outline what needs to be done and how, while testing is about validating that the change will work as intended before it is implemented. Thus, implementation is the key phase that directly addresses the execution of planned changes.