Finish-to-finish, also known by the two letter abbreviation of FF, refers to the particular and specific long term and logical relationship exists between one particular schedule activity and another particular schedule activity. In this relationship, the succeeding activity cannot finish until the preceding activity has ultimately been concluded. In some instances, the finish to finish estimation can take place at the start of the project. The project team can do a careful analysis of all of the estimated finish dates for the entire listing of schedule events that will take place throughout the life of the project. Then , the finish to finish for each individual gap of schedule activities can then be determined by subtracting the start date of one specific schedule activity from the end date of the preceding one. Additionally, the finish to finish can be modified by adjusting the expected start date of one following activity or attempting to modify the finish date of the preceding activity.
This term is defined in the 3rd and the 4th edition of the PMBOK.