In project scheduling terminology, the estimated time required to perform a specific activity is called its duration.

Introduction / Context:
Precise terminology underpins CPM/PERT analysis. Confusing duration, float, events, and dummies leads to planning and control errors. This question checks the exact term for the time needed to execute an activity.

Given Data / Assumptions:

• An activity has an estimated completion time under normal conditions.
• We must name that quantity correctly.

Concept / Approach:
Duration is the planned time for an activity from its start to its finish. It is distinct from float (schedule flexibility), an event (a point in time marking start/finish), or a dummy (a zero-duration logical connector in AOA networks).

Step-by-Step Solution:
1) Identify the quantity described: time needed to do the work.2) Map to definitions: duration = required time; float = allowance; event = node; dummy = zero-time logic.3) Conclude the correct term is duration.

Verification / Alternative check:
Standard CPM/PERT texts define activity time as duration; float is derived later from early/late times and critical path calculations.

Why Other Options Are Wrong:

• Event: Instant in time, not a span.
• Dummy: Has no time; indicates logic only.
• Float: Not required time, but schedule leeway.

Common Pitfalls:

• Using float and duration interchangeably.
• Assuming dummy activities consume time.

Final Answer:
Duration.