PERT/CPM scheduling: what is the name of the latest time an event can occur without delaying completion of the entire project?

Introduction / Context:
Program Evaluation and Review Technique (PERT) and Critical Path Method (CPM) compute event times to identify schedule flexibility. Understanding “earliest” and “latest” times is essential to locate slack and protect the project completion date.

Given Data / Assumptions:

• An “event” marks completion of preceding activities and enables successors.
• We want the latest occurrence time that still preserves the planned project finish date.
• Network times are typically computed via forward and backward passes.

Concept / Approach:
The latest allowable time (also called latest event time) is computed during the backward pass. It represents the latest occurrence without impacting the project end. The difference between the latest and earliest event times indicates slack; zero slack events lie on the critical path.

Step-by-Step Solution:

Verification / Alternative check:
Project management references define earliest vs. latest times and tie criticality to zero slack (LET − EET = 0).

Why Other Options Are Wrong:
“Earliest allowable time” refers to forward-pass results; “earliest pass” and “latest pass” are actions (computations), not the time itself. “None” is incorrect because the proper term exists.

Common Pitfalls:
Confusing activity floats with event slack; mixing up earliest/latest activity start/finish (ES/EF, LS/LF) with event times; ignoring calendar constraints and resource leveling that can alter practical “allowable” times.

Final Answer:
latest allowable time