Whether this is a viable answer or not depends on what you mean by 'update', but if a solution that allows Task B in Project #2 to understand that it's ready to start after Task A in Project #1 is completed, you could utilize the Cross-Project Predecessor feature.
If that doesn't sound like something that would work, can you elaborate more on a use-case for what you're trying to accomplish? If we knew where you were trying to get, there might be another creative workaround.
Thanks Katherine for the response, but that is not exactly what I'm looking for. We currently use the cross project predecessor, but we are looking for something a little different.
Let me try to clarify . . . I have two Projects (Project A and Project B). I also have a task that is the same for both projects let's call it Task: Marketing Collateral. . . . In this case, the same marketing collateral will be used for the work being done for both Project A and Project B. . . . Therefore, I have a Task: Marketing Collateral in both Project A and Project B. I'm hoping there is some way to link these two tasks so that when I complete the Task: Marketing Collateral in Project A, the Task: Marketing Collateral in Project B automatically completes as well.
I'm usually pretty good at system trickery, but this one has me stumped. There's no way I can think of to make one task auto-complete based on another being completed. If they happen to be in the same program or portfolio, you could use a custom form field to flag which tasks are ready to be completed and then use a set of filtered task reports to allow someone to quickly select all of them to close at once but that's about all I've got.
The Task Tracking Mode settings really control what you're looking at here. Depending on how consistent your team are at maintaining project/task deadlines, some version of Auto Complete might be your best option on this one.
Other than that, I'd try your Account person with Workfront. They might have something else up their sleeve I'm not thinking of on this one.