Network scheduling terminology (PERT/CPM): The start or completion of a task (with no duration itself) is called a(n) ________.

Introduction / Context:
PERT/CPM models represent projects as networks of activities and events. Correct terminology is essential for reading and building these networks.

Given Data / Assumptions:

• Activities consume time and possibly resources.
• Events (nodes) mark the start or finish of activities and have zero duration.
• Precedence relationships connect events via activities.

Concept / Approach:
In activity-on-arrow (AOA) or activity-on-node (AON) representations, the notion of a milestone (event) captures the instant a state is achieved (e.g., “foundation complete”). It has no time span; activities carry duration.

Step-by-Step Solution:

Verification / Alternative check:
Network definitions: nodes/milestones/events have zero duration; arcs/activities have positive duration.

Why Other Options Are Wrong:
(b) Activity always has duration; (c) duration is a quantitative attribute, not an object; (d) contradicts standard definitions.

Common Pitfalls:
Using “activity” and “event” interchangeably; assigning duration to events.

Final Answer:

Event