The correct answer is: A. Longest duration.
Crashing is a technique used in project management to shorten the project schedule by adding resources to activities on the critical path. The critical path is the longest path through a project network diagram, and it determines the overall project duration. By crashing activities on the critical path, the project duration can be shortened.
The cost slope of an activity is the amount of additional cost incurred for each additional unit of time saved. The cost slope of an activity is determined by the activity’s cost and duration. Activities with a high cost slope are more expensive to crash than activities with a low cost slope.
When crashing activities, it is important to start with the activities that have the longest duration and the highest cost slope. This will result in the greatest reduction in project duration for the least amount of additional cost.
Here is a brief explanation of each option:
- Option A: Longest duration. This is the correct answer. Activities with a longer duration have a greater impact on the project schedule, so they should be crashed first.
- Option B: Highest cost slope. This is not the correct answer. Activities with a high cost slope are more expensive to crash, but they do not necessarily have a greater impact on the project schedule.
- Option C: Least cost slope. This is not the correct answer. Activities with a low cost slope are less expensive to crash, but they also have a smaller impact on the project schedule.
- Option D: Shortest duration. This is not the correct answer. Activities with a shorter duration have a smaller impact on the project schedule, so they should be crashed last.