Data Type Integer List (integer list field: A type of field whose content is a list of whole numbers separated by the list separator character, typically a comma. Examples include the Predecessors and Successors fields.)
Entry Type Entered (entered field: A field in which you may type or edit information. This is in contrast with a calculated field, in which Project calculates and enters information.)
Description The Unique ID Predecessors field lists the unique ID (unique ID: A unique number that Project automatically assigns to a task, resource, or assignment. It will not change as other tasks or resources are added to or removed from the project.) numbers for the predecessor (predecessor: A task that must start or finish before another task can start or finish.) tasks on which a task depends before it can be started or finished. Each predecessor is linked to the task by a specific type of task dependency (task dependencies: A relationship between two linked tasks; linked by a dependency between their finish and start dates. There are four kinds of task dependencies: Finish-to-start [FS], Start-to-start [SS], Finish-to-finish [FF], and Start-to-finish [SF].) and a lead time (lead time: An overlap between tasks that have a dependency. For example, if a task can start when its predecessor is half-finished, you can specify a finish-to-start dependency with a lead time of 50 percent for its successor [has a negative lag value].) or lag time (lag time: A delay between tasks that have a dependency. For example, if you need a two-day delay between the finish of one task and the start of another, you can establish a finish-to-start dependency and specify a two-day lag time [has a positive value].).
Best Uses Add the Unique ID Predecessors field to a task view when you want to display or update task predecessors as identified by their unique IDs rather than task IDs. Each predecessor is represented by its unique ID number, which may be followed by a dependency and the lead or lag time. The dependency types for predecessors are FS (finish-to-start), FF (finish-to-finish), SS (start-to-start), and SF (start-to-finish). To enter lead time, type a negative number. To enter lag time, type a positive number.
Example You want to review the predecessors of tasks in your project to analyze and refine the schedule. You add the Unique ID field and the Unique ID Predecessors field to the Task Sheet view. In the Predecessors field for the "Write proposal" task, you see the entry "14FS+3d." This means that the task with Unique ID14 is a predecessor of this task, with a finish-to-start dependency and a 3-day lag time. Before this task can start, it must wait 3 days after the finish of the task with Unique ID14. The Unique ID Predecessors field for the "Conduct client meetings" task is blank. You type "15FS" to link this task to the task with Unique ID15 with a finish-to-start dependency.
Remarks If you enter only the task unique ID number in the Unique ID Predecessors field, Project assumes a finish-to-start dependency with zero lag time. If there is more than one predecessor, they are all listed and separated by the list-separator character (list-separator character: A character, usually a comma or semicolon, that separates elements in a list.), which is typically the comma.
You can use the Link Tasks command on the Edit menu to link the selected tasks with finish-to-start dependencies and zero lag time. You can also link tasks by dragging from one task to the other on the chart portion of the Gantt Chart or Network Diagram.
If a predecessor is a task in another project, the Unique ID Predecessors field also contains the path to the linked project, in addition to the task Unique ID and dependency type. An example is: C:\My Documents\Bldg E Construction.mpp\3FF.