In CPM terminology, the performance of a specific, measurable task consuming time and/or resources is called an activity (events are milestones; dummies carry logic only).

Introduction / Context:
Clear vocabulary prevents modeling errors in network schedules. CPM distinguishes work (activities) from milestones (events) and logic connectors (dummies).

Given Data / Assumptions:

• We seek the term for 'performance of a specific task'.
• Options include dummy, event, activity, contract.

Concept / Approach:
An activity represents work that takes time (duration) and may require resources. An event is a zero-duration point marking start/finish. A dummy is an artificial, zero-duration link to maintain logic or uniqueness in AOA networks. A contract is a legal instrument, not a scheduling element.

Step-by-Step Solution:
1) Map 'task performed' → work requiring duration → activity.2) Exclude event: marks completion/start without work.3) Exclude dummy: zero time, logic only.4) Exclude contract: legal/administrative, not a CPM element.

Verification / Alternative check:
CPM definitions universally define activities as the fundamental work units with durations and resource needs.

Why Other Options Are Wrong:

• Dummy: No work, no time—logic only.
• Event: Milestone node with zero duration.
• Contract: Commercial agreement, not a network component.

Common Pitfalls:

• Assigning duration to dummies (incorrect).
• Using events to represent work packages.

Final Answer:
Activity.