PERT Analysis within CPM

Correct Answer: The amount of time an activity can be delayed without affecting the project completion date

In PERT (Program Evaluation and Review Technique) Analysis and Critical Path Method (CPM), 'slack' refers to the time flexibility an activity has before it impacts the overall project completion date. This flexibility represents the amount of delay that can occur in an activity before it affects subsequent activities and the project's end date. It's also commonly known as 'float' in project management terminology. The other options are incorrect because: The difference between optimistic and pessimistic time estimates is actually the range of uncertainty, not slack. Additional time for risks and uncertainties is called contingency or buffer, not slack. The total float of activities on the critical path is always zero by definition - critical path activities have no slack, which is why they're critical.

Correct Answer: te = (O + 4M + P) / 6

The correct formula for calculating expected duration (te) in PERT Analysis is te = (O + 4M + P) / 6, where: O = Optimistic estimate M = Most likely estimate P = Pessimistic estimate This formula is based on a beta distribution and applies a weighted average where: - The most likely estimate (M) receives the highest weight (4) - The optimistic (O) and pessimistic (P) estimates each receive a weight of 1 This weighting reflects the statistical reality that the most likely estimate has the highest probability of occurrence, while extreme values (optimistic and pessimistic) are less probable. The denominator of 6 is the sum of all weights (1 + 4 + 1 = 6), ensuring that the weighted average is properly calculated. The other formulas presented are incorrect variations that use different weightings which do not align with PERT's statistical foundations and beta distribution principles.

Correct Answer: It accounts for uncertainty in activity durations by using optimistic, most likely, and pessimistic estimates

PERT (Program Evaluation and Review Technique) Analysis is primarily used to handle uncertainty in project scheduling by incorporating three time estimates: - Optimistic time (best-case scenario) - Most likely time (expected scenario) - Pessimistic time (worst-case scenario) This three-point estimation technique allows project managers to account for variability and risk in activity durations, resulting in more realistic schedule estimates. The other options are incorrect because: - Schedule float calculations with resource optimization is more related to resource leveling and smoothing techniques, not PERT analysis - Integration of cost and schedule baselines through weighted averages is more related to Earned Value Management, not PERT - Calculating exact durations from historical data describes analogous estimating, which is a different technique and doesn't account for current project uncertainties like PERT does