Finish-to-finish (FF)
A finish-to-finish (FF) dependency means the successor cannot finish until its predecessor has finished. The two tasks can overlap; what is tied together is their end.
FF fits work that tracks other work to its end, such as writing documentation alongside a build: the documentation can start early, but it cannot be finished before the thing it documents.
A late finish on the predecessor pushes the successor's finish, so FF passes delays on at the end of the task rather than the start.
Worked example
| Task | Duration | Depends on | Scheduled | Total float | After the delay |
|---|---|---|---|---|---|
| 1. Build | 10 days | None | Days 1 to 10 | 0 days | Days 1 to 13 |
| 2. User documentation | 6 days | 1FF | Days 5 to 10 | 0 days | Days 8 to 13 |
The delay: Build takes 3 days longer.
User documentation takes 6 days and must not finish before Build does, so it is scheduled for days 5 to 10, finishing with Build. If Build runs 3 days late, the documentation now finishes on day 13.
Open this example in the free delay simulator to change the durations, the links or the delay and watch the schedule move.