Sharepoint 2010: How to customize standard task list to have dependency tasks

Question

I have functional requirement to allow Sharepoint site users to put tasks in a task list with dependencies. For example there are tasks:

"A" assigned to "User1"

"B" assigned to "User2"

"C" that should be marked completed if "C1" assigned to "User1" and "C2" assigned to "User2" are marked completed simultaneously.

Is it possible to customize standard task list for such a thing? What are the steps I have to take in order to achieve such behavior with standard list?

Thank you in advance!

Answer 1

out of the box I'm unaware of a solution but you could use a related list and add either a workflow or event handler to automatically update the status of the parent task.

Answer 2

Workflow should be able to achieve what you need.