The addition of which of the following relationships would cause a logic loop?

A logic loop (circular dependency) occurs when an activity is made both a successor and a predecessor of itself through a chain of relationships, preventing forward or backward pass calculation. In the given network, activity F is already a predecessor of I; adding the opposite link “F-I” makes I simultaneously precede and follow F, completing a closed cycle. The network solver will flag this as “circular logic” and halt. None of the other listed relationships close an existing predecessor–successor chain, so they leave the logic acyclic.

A. O H-D adds a normal finish-to-start tie that does not feed back into H or O.
B. O C-J links two nodes that had no reciprocal ties, so no cycle forms.
D. O I-C also connects independent nodes without completing a predecessor → successor → predecessor loop.

1. AACE International Recommended Practice 49R-06

“Identifying the Critical Path

” §4.1

Circular Logic

pp. 5-6.

2. AACE International

Skills and Knowledge of Cost Engineering

6th ed.

Ch. 19

“Scheduling

” p. 379 (discussion of prohibited circular logic).

3. Stanford Univ. CEE-159/259 “Construction Planning & Control

” Lecture 7 notes

p. 4

“Circular relationships will cause CPM calculation failure.”