PMI-SP Activity Sequencing 5 — Questions and Answers
Question 1: A project manager is sequencing activities and realizes that Activity Y cannot finish until Activity X has been started. Which PDM relationship applies?
- Finish-to-Start (FS)
- Start-to-Start (SS)
- Finish-to-Finish (FF)
- Start-to-Finish (SF) (Correct answer)
Correct answer: Start-to-Finish (SF)
Start-to-Finish (SF) means the successor (Y) cannot finish until the predecessor (X) has started.
Question 2: During activity sequencing, the project team decides to sequence installation of electrical systems before plumbing based solely on crew availability preferences, even though either could go first physically. This is an example of:
- Mandatory dependency
- External dependency
- Discretionary dependency (Correct answer)
- Contractual dependency
Correct answer: Discretionary dependency
Discretionary dependencies are established based on knowledge of best practices or team preferences, not physical constraints.
Question 3: Which tool used during Sequence Activities helps a scheduler visualize and confirm that all logical relationships are complete and there are no open-ended activities?
- Work breakdown structure (WBS)
- Project schedule network diagram (Correct answer)
- Resource histogram
- Probability and impact matrix
Correct answer: Project schedule network diagram
The project schedule network diagram reveals open ends (activities with no predecessors or successors) that indicate incomplete logic.
Question 4: A schedule network shows Activity P with Total Float of 0 and Activity Q with Total Float of 4 days. Which statement is correct?
- Activity Q is on the critical path; Activity P has flexibility
- Activity P is on the critical path; Activity Q has 4 days of flexibility (Correct answer)
- Both activities are on the critical path
- Total float of 0 means the activity has been completed
Correct answer: Activity P is on the critical path; Activity Q has 4 days of flexibility
Zero total float means Activity P is on the critical path; Activity Q can be delayed up to 4 days without affecting the project end date.
Question 5: When using the Precedence Diagramming Method, what does a 'merge' activity represent?
- An activity that branches into multiple paths
- An activity that receives inputs from multiple predecessor activities (Correct answer)
- An activity added to replace a dummy activity
- An activity on the critical path with zero float
Correct answer: An activity that receives inputs from multiple predecessor activities
A merge activity is one that has multiple predecessors — multiple paths converge into a single activity.
Question 6: A PMI-SP is reviewing a schedule where the predecessor relationship between Design and Procurement is listed as 'FF+10d'. What does this mean?
- Procurement cannot finish until 10 days after Design finishes (Correct answer)
- Procurement must finish 10 days before Design finishes
- Procurement cannot start until 10 days after Design starts
- Design cannot finish until 10 days after Procurement finishes
Correct answer: Procurement cannot finish until 10 days after Design finishes
FF+10d means Finish-to-Finish with a 10-day lag: the successor (Procurement) cannot finish until 10 days after the predecessor (Design) finishes.
Question 7: A project network diagram includes an activity with no predecessors. What is this type of activity called, and what should a scheduler verify?
- A merge node; verify it has multiple successors
- A source node; verify it is intentionally the start of a path and not missing a predecessor (Correct answer)
- A dummy activity; verify it has duration assigned
- A burst node; verify all paths are critical
Correct answer: A source node; verify it is intentionally the start of a path and not missing a predecessor
An activity with no predecessors is a source node and should be verified as an intentional network start, not an omitted dependency.
PMI-SP Activity Sequencing 5
A project manager is sequencing activities and realizes that Activity Y cannot finish until Activity X has been started.
Which PDM relationship applies?