CST Schedule Compression & Acceleration Techniques 1 — Questions and Answers
Question 1: What is 'crashing' in the context of schedule compression?
- Reducing activity durations by adding resources (Correct answer)
- Removing non-critical activities from the schedule
- Overlapping sequential activities to save time
- Eliminating float from the critical path
Correct answer: Reducing activity durations by adding resources
Crashing adds resources (labor, equipment, etc.) to critical path activities to shorten their duration, typically at increased cost.
Question 2: Which schedule compression technique involves overlapping activities that would normally be performed sequentially?
- Crashing
- Fast-tracking (Correct answer)
- Resource leveling
- Schedule baselining
Correct answer: Fast-tracking
Fast-tracking overlaps activities normally done in sequence, reducing project duration but increasing risk of rework.
Question 3: What is the primary trade-off when using the crashing technique?
- Increased scope vs. reduced duration
- Increased cost vs. reduced duration (Correct answer)
- Increased risk vs. reduced resources
- Increased float vs. reduced milestones
Correct answer: Increased cost vs. reduced duration
Crashing reduces project duration by adding resources, which directly increases project costs.
Question 4: When applying fast-tracking, which type of dependency is most commonly modified?
- Mandatory finish-to-start dependencies
- Discretionary finish-to-start dependencies (Correct answer)
- External finish-to-start dependencies
- Mandatory start-to-start dependencies
Correct answer: Discretionary finish-to-start dependencies
Discretionary (soft logic) finish-to-start dependencies are most commonly modified in fast-tracking because they are not technically required.
Question 5: In schedule crashing analysis, the 'crash cost slope' is calculated as:
- (Crash Cost - Normal Cost) / (Normal Duration - Crash Duration) (Correct answer)
- (Normal Cost - Crash Cost) / (Crash Duration - Normal Duration)
- (Crash Duration - Normal Duration) / (Crash Cost - Normal Cost)
- (Normal Duration + Crash Duration) / (Normal Cost + Crash Cost)
Correct answer: (Crash Cost - Normal Cost) / (Normal Duration - Crash Duration)
The crash cost slope equals (Crash Cost - Normal Cost) divided by (Normal Duration - Crash Duration), representing the additional cost per unit of time saved.
Question 6: Which of the following is a primary risk associated with fast-tracking?
- Increased project cost due to overtime pay
- Increased rework if errors in overlapped activities propagate downstream (Correct answer)
- Reduced resource availability on critical activities
- Extended baseline duration beyond contract requirements
Correct answer: Increased rework if errors in overlapped activities propagate downstream
Fast-tracking increases rework risk because errors in early activities may require corrections in later activities that began before the upstream work was verified.
Question 7: Schedule recovery plans are most commonly triggered when:
- Total float exceeds 10 days on all paths
- The Schedule Performance Index (SPI) falls below an acceptable threshold (Correct answer)
- Resources are over-allocated by more than 50%
- The project achieves milestone completion ahead of schedule
Correct answer: The Schedule Performance Index (SPI) falls below an acceptable threshold
A schedule recovery plan is typically initiated when SPI or float analysis indicates the project is significantly behind the approved baseline.
CST Schedule Compression & Acceleration Techniques 1
What is 'crashing' in the context of schedule compression?