The precedence diagramming method (PDM) is also known as:

According to the PMBOK® Guide, specifically within the Sequence Activities process, the Precedence Diagramming Method (PDM) is a technique used for constructing a schedule model in which activities are represented by nodes and are graphically linked by one or more logical relationships to show the sequence in which the activities are to be performed.

Activity-On-Node (AON): This is the alternative name for PDM. In this method, each " node " (typically a box) represents a specific project activity. The dependencies or logical relationships between these activities are represented by arrows connecting the nodes.

Logical Relationships: PDM/AON supports four types of dependencies:

Finish-to-Start (FS): The successor activity cannot start until the predecessor activity has finished.

Finish-to-Finish (FF): The successor activity cannot finish until the predecessor activity has finished.

Start-to-Start (SS): The successor activity cannot start until the predecessor activity has started.

Start-to-Finish (SF): The successor activity cannot finish until the predecessor activity has started.

Dominance in Industry: PDM is the most commonly used method in modern project management software.

Comparison with Other Options:

Arrow Diagram (A): This refers to Activity-on-Arrow (AOA) or the Arrow Diagramming Method (ADM). In this older technique, activities are represented by the arrows themselves, and nodes represent milestones or " events. " It only supports Finish-to-Start relationships.

Critical Path Methodology (CPM) (B): CPM is a schedule network analysis technique used to estimate the minimum project duration and determine the amount of scheduling flexibility. While it uses PDM/AON diagrams to perform its calculations, it is the analytical method, not the name of the diagramming technique itself.

Schedule network diagram (D): This is a general term for any graphical representation of the logical relationships among the project schedule activities. PDM is a type of schedule network diagram, but the question asks for what PDM is specifically " known as " (its synonym).