These network diagrams have developed into Precedence Diagrams in which the activity is on the node, and arrows show the relationship between activities and the direction of the flow. They depict four types of relationships between the activities, namely
- Finish to Start – to be able to start the successor activity the predecessor activity must be finished
- Start to Start – the successor activity can be started shortly after starting the predecessor activity
- Start to Finish – successor activity must be started to finish the predecessor activity
- Finish to Finish – successor activity must be finished to finish the predecessor activity
MS-Project is based on these Precedence Networking diagrams and allows each of the four types of relationships.
Many using MS-Project do not realize how these Precedence Networking diagrams function. If no relationship is explicitly defined, it assumes a Finish-to-Start relationship. In reality, we use Start-to-Start relationships more frequently, or at least as frequently asthe Finish-to-Start relationship. When we do not use the proper relationship, the resulting schedule cannot be realistic.