What does a precedence diagram illustrate?

A precedence diagram is primarily used in project management to illustrate the sequence of tasks and their interdependencies. It provides a visual representation of how different tasks relate to each other in terms of their order of execution. Specifically, it shows which tasks must be completed before others can begin, identifying not only the tasks themselves but also the relationships that define the workflow of the project. This is critical for planning and scheduling as it helps project managers understand the critical path, allocate resources effectively, and mitigate potential delays.

The diagram helps in visualizing the flow of tasks and allows for better forecasting of the project's timeline. This understanding aids in efficient decision-making and prioritization to ensure project deadlines are met.

The other options mention aspects like budget allocations, task deadlines, and expense tracking, which, while important to project management, do not pertain to the primary function of a precedence diagram. Such diagrams focus solely on task sequencing and dependencies rather than financial management or schedule enforcement.