Network Diagram

A network diagram is a visual map of all tasks in a project and the logical dependency relationships between them. Each task appears as a node, and directed arrows between nodes represent the predecessor-to-successor relationships that control sequence. The complete set of nodes and arrows forms the logic network that the scheduling engine traverses to calculate the critical path and earliest possible project completion date.

Nodes and Arrows

The most common format for project scheduling is the Precedence Diagramming Method (PDM), also called Activity-on-Node (AON): each box or rectangle is a task, and arrows point from predecessor to successor. The arrow type encodes the relationship — Finish-to-Start, Start-to-Start, Finish-to-Finish, or Start-to-Finish — and may carry a lag value. Every path through the network from the first task to the last represents a possible sequence through the project; there may be dozens or hundreds of paths in a complex schedule.

Forward Pass and Backward Pass

The scheduling engine calculates two sets of dates for every task:

• Forward pass — starting from the project start date, the engine follows arrows forward through the network, computing the earliest possible start and finish for each task.
• Backward pass — starting from the project end date, the engine follows arrows in reverse, computing the latest allowable start and finish for each task without pushing the end date later.

The difference between a task's latest allowable start and its earliest possible start is its float. Tasks with zero float are on the critical path — their early and late dates are identical, meaning any delay directly extends the project end date.

Why the Network Diagram Matters

A list of tasks with durations tells you how long each piece of work takes, but not when any of it must happen or what the project end date will be. The network diagram adds the second dimension — logical sequence — that makes scheduling possible. Two tasks each requiring 10 days can finish in 10 days if they can run in parallel, or 20 days if one must finish before the other starts. Without the network, you cannot know which applies.

The network diagram also reveals parallel paths. When two sequences run side by side and converge on a successor, the longer path becomes critical. Shortening the shorter path has no effect on the project end date; only the longer, critical path matters. This insight — invisible from a simple task list — is only visible in the network.

Network Diagrams in Maverick

Maverick builds and maintains the task dependency network automatically from the predecessor and successor links you set on each task. The Gantt chart with its dependency arrows is the visual representation of the project network — every arrow in the Gantt view is an edge in the underlying logic network. Critical path highlighting shows which path through the network is longest. For more on how critical path calculation works, see the guide: The Critical Path in Project Management.

Related Terms

Critical Path  ·  Task Dependency  ·  Predecessor  ·  Float  ·  Schedule Compression