Which of the following statement(s) is/are correct regarding Activity on Node method of analysis? (i) Many dummy activities are used (ii) Only required number of dummy activities are used (iii) No dummy activity is used (iv) Activities are represented by nodes
- A(i) and (ii)
- B(ii) and (iii)
- C(iii) and (iv)Correct
- D(i) and (iv)
Solution
Concept
Activity on Node network representation and characteristics
Formula
NONE
Step-by-step solution
1. In Activity on Node (AON) networks, activities are represented by nodes, while arrows define precedence relationships (Statement iv is correct). 2. Because arrows define logical relationships directly between nodes, dummy activities are never required in an AON network (Statement iii is correct; Statements i and ii are incorrect). 3. Therefore, statements (iii) and (iv) are correct. Answer: C
Explanation
In Activity-on-Node (AON) network analysis, activities are represented by nodes, and arrows represent precedence relationships between them. Because predecessor and successor dependencies are directly linked between nodes, dummy activities are not needed. Therefore, no dummy activity is used, making statements (iii) and (iv) correct.
Why the other options are wrong
A) Incorrect because statement (i) does not apply to AON networks where no dummy activities are used. B) Incorrect because dummy activities are not needed at all in AON. D) Incorrect because statement (i) is false and statement (iii) is true.
Shortcut
AON = Activities on Nodes + NO dummy activities (arrows show precedence only).
Common mistake
Confusing AON with Activity on Arrow (AOA) networks, which require dummy activities to maintain precedence logic.
Correct answer: C) (iii) and (iv)