CST Critical Path & Float Analysis 3 — Questions and Answers
Question 1: During a forward pass calculation, what values are determined for each activity?
- Late Start and Late Finish
- Early Start and Early Finish (Correct answer)
- Total Float and Free Float
- Duration and Resource requirements
Correct answer: Early Start and Early Finish
The forward pass calculates Early Start and Early Finish dates by moving from the project start toward the end.
Question 2: When performing a backward pass in CPM, which date is used as the starting point?
- The project Early Start date
- The earliest Late Finish of all terminal activities
- The project end date (or Late Finish of the last activity) (Correct answer)
- The baseline start date
Correct answer: The project end date (or Late Finish of the last activity)
The backward pass begins at the project end date (Late Finish of the terminal activity) and works backward to determine Late Finish and Late Start for all activities.
Question 3: If Activity P has an Early Finish of day 20 and its only successor Activity Q has an Early Start of day 25, what is Activity P's Free Float?
- 0 days
- 5 days (Correct answer)
- 20 days
- 25 days
Correct answer: 5 days
Free Float = Early Start of successor − Early Finish of the activity = 25 − 20 = 5 days.
Question 4: A project has multiple end activities (A, B, C) with Early Finish dates of 30, 35, and 28 days respectively. What is the project duration?
- 30 days
- 28 days
- 35 days (Correct answer)
- 93 days (sum of all)
Correct answer: 35 days
The project duration is the longest Early Finish among all terminal activities, which is 35 days.
Question 5: Which statement correctly describes the relationship between Total Float and Free Float?
- Free Float is always greater than or equal to Total Float
- Total Float is always greater than or equal to Free Float (Correct answer)
- They are always equal on critical path activities
- Free Float and Total Float are independent measures with no relationship
Correct answer: Total Float is always greater than or equal to Free Float
Total Float is always greater than or equal to Free Float because Free Float is a subset of the available Total Float.
Question 6: A Finish-to-Start relationship with a lag of 3 days means:
- Activity B must start 3 days before Activity A finishes
- Activity B can start 3 days after Activity A starts
- Activity B cannot start until 3 days after Activity A finishes (Correct answer)
- Activity A must finish 3 days after Activity B starts
Correct answer: Activity B cannot start until 3 days after Activity A finishes
An FS+3 lag means the successor (B) must wait 3 days after the predecessor (A) finishes before it can begin.
Question 7: What is the primary purpose of a schedule compression technique called 'fast-tracking'?
- Adding resources to shorten activity durations
- Performing activities in parallel that were originally planned sequentially (Correct answer)
- Eliminating low-priority activities from the schedule
- Reducing the scope of work to meet deadlines
Correct answer: Performing activities in parallel that were originally planned sequentially
Fast-tracking overlaps activities that were originally planned in sequence, which can shorten the project duration but increases risk.
CST Critical Path & Float Analysis 3
During a forward pass calculation, what values are determined for each activity?