A network will have only one initial node. Initial node will have only outgoing arrows.

A network can have only one final node. Final node will have only incoming arrows.

No activity can start until its tail event has occurred.

An event cannot occur until all the activities leading upto it are completed.

No event can occur twice. Hence network looping is not permitted.

An arrow should represent a singular situation. Individuality and separate entity of each activity should be maintained.

The network should be drafted such that all activities are completed to reach the end objective.

All constraints and interdependencies should be shown properly on the network using dummies.

Network logic should always be maintained.

The time flow is usually shown from left to right.