Which activity common to all project management processes must have a plan?

In project management, the activity that must have a plan is closely associated with the processes of controlling. This phase involves monitoring project performance and progress against the planned objectives and requires a structured approach to ensure that the project stays on track. A comprehensive plan is essential in controlling because it provides the benchmarks against which performance can be measured, facilitating corrective actions as needed.

The planning aspect in controlling is critical because it outlines the desired outcomes, sets performance criteria, and establishes the means to assess project status. Without a plan in place during the controlling process, it would be difficult to identify variances from the planned performance, thus impacting the project’s success.

While other phases like initiating, executing, and closing also involve various forms of planning, the ongoing nature of controlling relies heavily on a predetermined plan to guide day-to-day management and decision-making throughout the project lifecycle.