State automation relative to a Child work item!

 Hello, I would like to get some information on what sort of relationships there are between a parent and child work item.  As I understand the out-of-the-box preconditions state that you can prevent a parent work item from moving forward until all the child work items are closed. My question is, can you make a parent work item automatically change state dependent on closure or opening of child work items? Any information around this, work-arounds or anything related would be extremely helpful. Thanks