Which method is used to calculate earliest start (ES) and earliest finish (EF) times?

Which method is used to calculate earliest start (ES) and earliest finish (EF) times?

• A. Forward Pass
• B. Backward Pass
• C. Critical Path Method
• D. PERT

Answer: (A)

The essential idea is to propagate the earliest possible times through the network, starting from the project start. This is done with the forward pass. For each activity, its earliest start is the maximum of the earliest finishes of all its predecessors (so every prerequisite has finished), and its earliest finish is that start plus the activity’s duration. For example, if an activity depends on two predecessors finishing at days 4 and 6, its earliest start would be 6, and its earliest finish would be 6 plus its duration. This approach ensures you’re accounting for all dependencies and finding the true earliest times. The backward pass computes the latest times, like latest start and latest finish, by propagating from the end of the project backward and thus is not used to obtain ES/EF. The Critical Path Method describes the overall technique to determine project duration and identify the critical path, using both forward and backward passes. PERT is a probabilistic time-estimation approach, not the specific method for ES and EF.

The essential idea is to propagate the earliest possible times through the network, starting from the project start. This is done with the forward pass. For each activity, its earliest start is the maximum of the earliest finishes of all its predecessors (so every prerequisite has finished), and its earliest finish is that start plus the activity’s duration. For example, if an activity depends on two predecessors finishing at days 4 and 6, its earliest start would be 6, and its earliest finish would be 6 plus its duration. This approach ensures you’re accounting for all dependencies and finding the true earliest times.

The backward pass computes the latest times, like latest start and latest finish, by propagating from the end of the project backward and thus is not used to obtain ES/EF. The Critical Path Method describes the overall technique to determine project duration and identify the critical path, using both forward and backward passes. PERT is a probabilistic time-estimation approach, not the specific method for ES and EF.