In backward scanning, which value is used at each vertex?

In backward scanning, the Latest Start Time (LST) is used at each vertex to determine when an activity can start without delaying the project. This method is applied in project management, particularly in critical path analysis, where it helps in scheduling tasks efficiently along a project timeline.

The LST value ensures that all subsequent activities can still be completed by their required finish times. By calculating the LST for each vertex in reverse order, you establish constraints for project scheduling, allowing project managers to identify the latest possible moment a task can commence without affecting the overall project deadline.

This approach is particularly useful in finding the critical path of a project, as it pinpoints which tasks can be delayed and which must stay on schedule to avoid project delays. In contrast, other values like Earliest Start Time (EST) focus on when activities can begin based on their predecessors, which is a forward-looking strategy, rather than determining the latest permissible start times needed for project completion.