Network Analysis MCQ with answer and solution

Concept

Interfering float is the portion of total float that affects the start of following activities. It is equal to the head event slack.

Formula

Interfering Float = Total Float - Free Float = Head Event Slack (S_j)

Step-by-step solution

1. Total float (F_T) is the total extra time available for an activity without delaying the project completion. 2. Free float (F_F) is the extra time available without delaying the start of any following activity. 3. The difference between total float and free float is given by F_T - F_F. 4. This difference represents the head event slack, which is called Interfering Float. Answer: (C) Interfering Float

Explanation

Interfering float is the part of total float that interferes with the float of succeeding activities. It is equal to total float minus free float. It also equals the slack of the head event.

Why the other options are wrong

A: Independent float is the float unaffected by preceding or succeeding activities (Free float - Tail slack). B: Dependent float is not a standard network analysis term used for this difference. D: Critical float is not a standard term; activities on the critical path have zero total float.

Shortcut

Remember: Interfering Float = Total Float - Free Float = Head Slack (S_j).

Common mistake

Students often confuse independent float with interfering float. Independent float is free float minus tail event slack.