Which one of the following statements is not correct in respect of network diagram for time scheduling techniques?
- AIn a network, there must be only a single node and the initial node must have only outgoing arrows.
- BA network can have more than one final node.Correct
- CAn event cannot occur twice, i.e., there cannot be any network path looping back to previously occurred event.
- DAn event cannot occur until all the activities leading to it are completed.
Solution
Concept
Rules of network construction
Step-by-step solution
1. A network has a single initial event (with arrows only going out) and a single final event. 2. An event cannot occur twice, so no loops (c). 3. An event occurs only when all activities leading to it are complete (d). 4. So a network cannot have more than one final node; statement (b) is incorrect.
Explanation
The standard rules require one start event and one end event. Statement (a) is a garbled version of the "single initial node" rule, while (b) clearly contradicts the single-end-event rule.
Why the other options are wrong
(c) and (d) are fundamental rules. (a) is read as the single initial node rule.
Shortcut
One start, one end, no loops.
Common mistake
Allowing multiple end nodes.
Correct answer: B) A network can have more than one final node.