A dependency is the relationship between two tasks when action or activity on one determines key dates for the other. Start and finish dates of the task are the focus of the relationship between a predecessor and successor activity with logical relationships. Task dependencies come in four types (shown below in order of common use):
- Finish to Start – Task B can only start when Task A is complete
- Start to Start – Task B can only start when Task A starts
- Finish to Finish – Task B can only finish when Task A finishes
- Start to Finish – Task B can only finish when Task A starts
