Part 1Determining the earliest start time (ES) and earliest finish time (EF) for each activity is known as the _______________ through the network. A. slacking B. crashing C. backward pass D. forward pass

Question

Part 1Determining the earliest start time​ (ES) and earliest finish time​ (EF) for each activity is known as the​ _______________ through the network. A. slacking B. crashing C. backward pass D. forward pass

BlackTom AI · Accepted Answer

The forward pass computes earliest start (ES) and earliest finish (EF) times by moving from the project start toward the finish, so the correct answer is D. forward pass.

1) Relevant knowledge points and concepts
- Critical Path Method (CPM)/PERT networks use two main traversals: the forward pass (for earliest times) and the backward pass (for latest times).
- ES = earliest time an activity can start; EF = ES + activity duration.
- For an activity with multiple predecessors, ES = maximum of all predecessors’ EFs.
- Slack (float) is derived from ES/EF and latest start/finish (LS/LF).
- Crashing is a cost/time optimization technique to shorten durations.

2) Step-by-step reasoning process
- Begin at the start node: set ES(start) = 0 (or project start time).
- For each activity in topological order, compute EF = ES + duration.
- For each successor activity, set its ES equal to the maximum EF among all its immediate predecessors.
- Repeat until all activities’ ES and EF are computed at the finish node. This propagation from start to finish is the forward pass and yields the earliest feasible schedule.

3) Intermediate calculation example
- Suppose Activity A duration = 3. ES_A = 0 → EF_A = 0 + 3 = 3.
- Activity B and C both follow A. ES_B = ES_C = max(EF_A) = 3.
- If B duration = 2 → EF_B = 3 + 2 = 5. If C duration = 4 → EF_C = 3 + 4 = 7.
- A successor D of B and C has ES_D = max(EF_B, EF_C) = max(5,7) = 7.

4) Why the correct answer is correct
- The forward pass explicitly computes ES and EF by forward propagation using EF = ES + duration and ES(successor) = max(pred EF). That matches the question description exactly.

5) Why the other options are incorrect
- A. slacking: “slack” or “float” is a derived value (LS–ES or LF–EF), not the process to determine ES/EF.
- B. crashing: a schedule compression technique to reduce project duration at extra cost; not the computation of earliest times.
- C. backward pass: computes latest start (LS) and latest finish (LF) by moving from finish to start, not earliest times.

6) Conclusion
The process that determines ES and EF is the forward pass. Final answer: D. forward pass.

Part 1Determining the earliest start time (ES) and earliest finish time (EF) for each activity is known as the _______________ through the network. A. slacking B. crashing C. backward pass D. forward pass单项选择题

类似问题

Using the activity data below, identify the critical path and the total project duration. Activity Duration (Days) Predecessors A 4 - B 2 A C 4 A D 2 B E 5 B F 3 D, E G 2 F, C H 3 G I 4 E J 2 H, I

The critical path is the sequence of schedule activities determining the duration of the project, and is generally the shortest path through the project.

A project has the following activities: Activity Duration Predecessors A 5 - B 7 A C 6 A D 4 B, C E 3 D Using Critical Path Method (CPM), what is the total project duration?

What is the critical path method based on?

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Part 1Determining the earliest start time​ (ES) and earliest finish time​ (EF) for each activity is known as the​ _______________ through the network. A. slacking B. crashing C. backward pass D. forward pass单项选择题