Predecessor and Successor Tasks

Tasks can be either linked together or dependent on one another. The tasks involved in these interdependent relationships are either predecessor or successor tasks. Predecessor tasks come first and successor tasks follow. Predecessor tasks refer to tasks that must be completed or at least begin before another task can start. Successor tasks are those that follow the predecessor. Schedule managers have the ability to specify what must be done and by when to ensure a successful project outcome. For example, the Schedule Manager can designate that one task can only begin 20 days after a previous task is completed.

Finish to Start (FS) - Task 2 cannot start until task 1 finishes

Finish to Finish (FF) - Task 2 cannot finish until task 1 finishes

Start to Start (SS) - Task 2 cannot start until task 1 starts

Start to Finish (SF) - Task 2 cannot finish until task 1 starts

If predecessors are not defined in the import file or they need to be updated on the fly, schedule managers can do so by editing the individual task. You are able to define up to five predecessor tasks for an individual task record.

  1. Open the Schedule page.
  2. Right-click on the task that you want to define predecessors for and select Task Details.

    3. The Task Editor dialog is displayed.

  3. Click the Predecessors tab.
  4. To add a predecessor task, click Add New.
  5. In the new row, select the task that you want to add as a predecessor.
  6. In the Lag column, enter the amount of time in days, weeks or months that this task must endure before the subsequent task, or the task you've selected can begin or end.
  7. In the Type column, select one of the following options:
    • Finish to Start (FS) - Select this option if task 2 cannot start until task 1 finishes
    • Start to Start (SS) - Select this option if task 2 cannot start until task 1 starts
    • Finish to Finish (FF) - Select this option if task 2 cannot finish until task 1 finishes
    • Start to Finish (SF) - Select this option if task 2 cannot start until task 1 finishes
  8. Click OK to save your changes.
  1. Open the Schedule page.
  2. Right-click on the task that you want to add a new predecessor for.
  3. Select Add > Predecessor.
  4. Enter additional task information inline.
  5. Click Save.