Task 1 on Project 1 can only be started once the final milestone on Project...

In Workfront, cross-project predecessors allow dependencies between tasks across different projects. To ensure that Task 1 in Project 1 starts only after the final milestone of Project 2, the project manager must configure a cross-project predecessor linking the final milestone in Project 2 to Task 1 in Project 1. This establishes a dependency and aligns the timelines of the two projects​​.