In PERT/CPM network drawing conventions, identify the incorrect statement about how activities are represented by arrows and how networks are drawn.

Introduction / Context:
Network diagrams represent logical sequencing and timing relationships among activities and events. Understanding what the arrows and nodes mean, and what the diagram does not imply, prevents misinterpretation of schedule logic and durations.

Given Data / Assumptions:

• Activity on arrow representation is assumed.
• Arrow tail = activity start event; arrow head = activity finish event.
• Activity has finite duration, but the diagram is a logic map, not a scaled timeline.

Concept / Approach:
In Activity-on-Arrow diagrams, the arrow symbolises an activity that consumes time and resources. The diagram shows precedence relationships and event sequencing, not a scaled time axis. Therefore, arrows are not drawn to any physical scale of days, and the left-to-right convention is common but not mandatory or scaled.

Step-by-Step Solution:
Check the meaning of an arrow: it denotes an activity (true).Confirm arrow tail and head mapping to start and finish events (true).Recognise that an activity consumes time (true, but not drawn to scale).Identify the incorrect claim: arrows are drawn to scale from left to right (false).

Verification / Alternative check:
Scheduling textbooks state that networks are topological precedence diagrams. Bar charts (Gantt) are scaled to time, networks are not.

Why Other Options Are Wrong:

• Activity denoted by an arrow: Correct in AOA convention.
• Tail indicates start: Correct.
• Head indicates end: Correct.
• Each activity consumes time: Correct; the arrow signifies a duration, though the drawing is not scaled.

Common Pitfalls:
Interpreting spatial length of arrows as duration; assuming all networks must be left-to-right; confusing networks with bar charts.

Final Answer:
The arrows are drawn to scale from left to right.