Enforcingenables users to require that predecessor relationships happens without fail.
When setting predecessor relationships on a project, users can choose to enforce that relationship. Enforcing the relationship means that the relationship can’t be circumvented by users beginning tasks early. By enforcing a relationship between Task A and Task B, Task B will not be able to be marked as started until Task A is complete. Enforcing relationships applies to all predecessor types.
Keep in mind that enforcing relationships will lock the relationship to prevent users from starting tasks early.