Activity Details (9001 - "Spillway - Concrete"):

Duration: 175 days in the Normal schedule.

To calculate Late Start (LS), the Late Finish (LF) is required. LS is calculated by subtracting the activity's duration from the LF.

Formula for Late Start (LS):LS = LF.9001 - Dur.9001.

Date Calculation:

Late Finish (LF.9001) = 11-20-02 (given or derived).

Apply the formula:LS.9001 = LF.9001 - Dur.9001= 11-20-02 - 175 days.

Cross-Verification of Dates:

After subtracting 175 days, LS.9001 = 11-20-02.

Cross-Verification with Answer Options:

Option A: Incorrect. EF (Early Finish) is not needed for this calculation.

Option B: Incorrect. Uses LS and Dur incorrectly without connecting to LF.

Option C: Incorrect. Data provided is sufficient.

Option D: Correct. Matches both the formula and the date calculation.

References:

PSP Study Guide (2019), Section 2A – Schedule Development, Subsection on Backward Pass Calculations.

AACE Recommended Practices, RP 10S-90, discussing Late Start and Late Finish calculations.