Four Logical Relationships Between Tasks

Four logical relationships between tasks Finish to Start (default – what we’ve been doing in MS Project) Finish to Finish Start to Start Start to Finish

A Start-to-Start relationship is typically displayed as follows: In essence, they all sound the same. The start of the successor task is gated by the start of the predecessor activity. Until the predecessor starts, the successor cannot start. But here is another meaning people miss. It simply states the successor cannot start UNTIL the predecessor starts. It does not mean it has to start at exactly the same time. It can occur sometime after the beginning of the predecessor’s activity.

A Finish-to-Finish relationship is typically displayed as follows: In finish-to-finish relationships, we must wait for the predecessor task to finish before we can finish, or declare, the successor finished. And just as in start-to-start relationships, the successor doesn’t necessarily finish at the same time as the predecessor; it can finish after the predecessor. When serving dinner, we typically experience, or want to experience, a finish-to-finish relationship. We want all the food to be ready for eating at the same time and placed on the table, arranged for the family to eat.

A Start-to-Finish relationship is typically displayed as follows: The successor task finishes when the predecessor activity starts. Wait! How can the successor task finish, which means it started, before the predecessor activity starts? I don’t know about you, but this definition sounds screwy!. Fortunately, this relationship only occurs less than 1% of the time, so most people miss it, or simply don’t know it exists,