Which method is used to illustrate the relationships among all activities involved in a project?

The correct method to illustrate the relationships among all activities involved in a project is the Critical Path Method (CPM). This technique is specifically designed to identify the longest sequence of dependent tasks and determine the overall project duration. By laying out the logical sequence of activities, CPM allows project managers to visualize how tasks are interconnected, which tasks are critical for timely completion, and where there may be flexibility or slack time.

CPM focuses primarily on the relationships between activities, making it an essential tool for planning and scheduling. It helps in identifying the critical path—the sequence of tasks that cannot be delayed without affecting the project completion date. Understanding these relationships is crucial for effectively managing time and resources in a project setting.

The other methods, while valuable in project management, serve different purposes. The Earned Value Method focuses on performance measurement by comparing the work performed with the planned work, rather than illustrating relationships among project tasks. A Work Breakdown Structure (WBS) is a hierarchical decomposition of the total scope of a project into manageable sections, but it does not inherently show the relationships or dependencies among activities. Resource Allocation, on the other hand, deals with assigning available resources to various project tasks and does not illustrate the relationships among those tasks in the same manner as CPM does.