You’ve practiced adding dependencies throughout this tutorial. What you might interesting is that you’re not limited to creating internal dependencies, and you can add an item from another project as a predecessor. Just search for the name, and select it from the list. It works exactly like other dependencies. You can even make one project the predecessor of another.
There’s just one difference between internal and external dependencies. When you’re working on your project, it’s rescheduled automatically after every relevant change; e.g., changing the duration of an item, changing a dependency, and changing status of an item. However, these triggers don’t reschedule other projects. The result is that if you have an external predecessor, and the predecessor changes because of an update in the external project, you won’t see that change in your project until you do something that triggers your own project to reschedule.
It’s a compromised we’ve made, because if we reschedule all related projects after each trigger, it has the potential to exponentially expand to rescheduling of a network of a few million items, which slows down the system.