Node

A Node is a specific point on a schedule network diagram where dependency lines connect, representing an activity, event, or milestone within the project schedule. Nodes are the building blocks of precedence-based diagrams, showing how work is sequenced and where relationships begin or end.

Purpose and Characteristics

• Represents Work or Milestones – Each node typically reflects a scheduled activity or significant event.
• Connects Dependencies – Links are drawn between nodes to indicate logic-driven relationships.
• Used in PDM – Central to the Precedence Diagramming Method (PDM), where nodes are activities and arrows are dependencies.
• Visualizes Flow – Helps communicate sequencing, timing, and critical path relationships.

Example Scenario

In a construction project, nodes might include:

• Pour Foundation
• Frame Walls
• Install Electrical

Each is represented as a node, connected by dependency lines indicating that one must finish before the next can start.

Mermaid Diagram: Nodes and Dependencies in a Network

flowchart LR
    A[Pour Foundation] --> B[Frame Walls]
    B --> C[Install Electrical]
    C --> D[Final Inspection]

Each box is a node, and the arrows show the dependencies between them, forming a simplified portion of a project network diagram.

Why Nodes Matter

• Enable Structured Scheduling – Allow planners to define and control the sequence of work.
• Support Analysis – Used to identify paths, calculate float, and analyze scheduling risk.
• Improve Communication – Visually organize complex task relationships for stakeholders.

See also: Precedence Diagramming Method, Project Schedule Network Diagram, Network Logic, Dependency.