Question

Which one of the following relates to determination of critical path in PERT?

• A. Activity-oriented slack
• B. Event-oriented slack
• C. Event-oriented float
• D. Activity-oriented float

Hint:

In PERT, the critical path is composed of events that have zero event-oriented slack. This means there is no flexibility in their timing; any delay in these events will directly lead to a delay in the overall project completion.

Answer 1

The Correct Option is B

Step 1: Understand PERT and Critical Path.
PERT (Program Evaluation and Review Technique) is a project management tool used to schedule, organize, and control complex projects. The critical path in PERT is the longest sequence of activities that must be completed on time for the entire project to be completed on time. Any delay on the critical path directly delays the project completion.
Step 2: Define Slack and Float in PERT/CPM.
Slack (or float) refers to the amount of time an activity or event can be delayed without delaying the project completion date. In PERT, the analysis often focuses on events (nodes) rather than just activities (arcs).
Event-oriented slack is the difference between the latest allowable time and the earliest expected time for an event.
Step 3: Relate slack/float to the critical path.
The critical path is identified by events (or activities) that have zero slack/float. If an event has zero slack, it means its earliest expected time and latest allowable time are the same, indicating it lies on the critical path.
Step 4: Evaluate the given options.
Option 1: Activity-oriented slack. While activity slack exists, in PERT, the concept of slack is often applied to events to determine the critical path.
Option 2: Event-oriented slack. This directly relates to the determination of the critical path in PERT. Events on the critical path will have zero event slack.
Option 3: Event-oriented float. "Float" is a term more commonly used in CPM (Critical Path Method) for activities, while "slack" is more prevalent in PERT for events. Both refer to similar concepts of flexibility in scheduling. However, the term "event-oriented slack" is specifically mentioned as relating to critical path determination in PERT.
Option 4: Activity-oriented float. This is primarily a concept in CPM for activities.
The final answer is $\boxed{\text{2}}$.