The Project management application supports two types of external dependencies - hard and soft.

The type of external dependency can be set during adding a dependency between two projects tasks on the planning console.

Hard dependencies

In a hard dependency, any changes made in the predecessor project are automatically propagated to the successor project. A notification for the changes made is triggered in the successor project. The following image shows the process flow for a hard dependency type:
Figure 1. External hard dependency
Process flow for a hard dependency type

Soft dependencies

In a soft dependency, any changes made in the predecessor project trigger a notification in the successor project. As the project manager of the successor project, you can choose to accept or reject the changes in the notification. If you accept the notification changes, the changes in the predecessor project are synced to the successor project and the project is recalculated. If you reject the notification changes, the changes are not propagated to the successor project. The following image shows the process flow for a soft dependency type:
Figure 2. External soft dependency
Process flow for a soft dependency type