What type of dependency is represented by Start-to-Finish (SF)?

In project management, a Start-to-Finish (SF) dependency indicates that one task's completion is contingent upon the commencement of another task. More specifically, it means that the second task cannot be finished until the first task has started. This type of dependency is somewhat unconventional compared to the more commonly used dependencies, but it serves specific scenarios where the timing of task completions and starts is critical to project flow.

For instance, in a scenario where a new system is being implemented, the old system (Task A) must start operating before the new system (Task B) can officially finish its transition and be considered fully operational. This emphasizes the sequential connection where the beginning of one event directly influences the conclusion of another.

The other options do not accurately define the Start-to-Finish dependency. While some describe relationships between tasks, they do not capture the unique essence of SF, which is focused on the requirement that the start of one task is essential for the completion of another.