If you did not select the Allow Out-of-Sequence Progressing option on the Progress tab of the Projects form, PM Compass uses the following rules to determine if you can enter schedule progress for a successor activity.
If the relationship type is:
Finish to Start (FS) — PM Compass checks that there is an actual finish date defined for the predecessor task and that this date is on or before the successor task's actual start date.
Start to Start (SS) — PM Compass checks that there is an actual start date defined for the predecessor task and that this date is on or before the successor task's actual start date.
Start to Finish (SF) — PM Compass checks that there is an actual start date defined for the predecessor task and that this date is on or before the successor task's actual finish date.
Finish to Finish (FF) — PM Compass checks that there is an actual finish date defined for the predecessor task and that this date is on or before the successor task's actual finish date.