Why Can't I Set a Gantt Chart Dependency in my Plan Between Execution Items and Plan Items?
I am building a plan and using the Gantt chart. I have a plan item X with several execution items as children (A, B, C). The plan item (X) has a sibling execution item (Y). I would like the sibling execution item (Y) to treat the plan item (X) as a predecessor such that the execution item (Y) cannot begin until the plan item (X) is resolved. If I set the execution item's (Y) predecessor to the last child of the plan item (X/C), this works just fine. The execution item (Y) does not start in the Gantt chart until after item C is finished. However, if I set the predecessor of execution item Y to plan item X instead, then the execution item (Y) is allowed to start immediately (concurrently with the plan item (X)).
It appears that there is a rule that the Gantt chart doesn't work unless predecessor/successor is execution item to execution item (and presumably plan item to plan item). Is this correct or am I missing something?
Is there a reason why it is implemented this way?
Accepted answer
plan cannot be the predecessor of an execution item it contains.
plan runs in parallel to the work..
Comments
Okay, so it sounds like it's just implemented that plan items all "start" concurrently, regardless of when the execution items that make up those plan items are actually starting. So it sounds like the Plan Items in the context of the Gantt chart are only there to provide logical groupings and show the maximum length of the associated child execution items. It doesn't appear that they play much of a role in terms of schedule.
I'm not sure I understand the reason why it has to be this way, but I guess I don't see a reason why it shouldn't be either. I think I was partly wondering if I had done something wrong and this schedule behavior I was observing was anomalous, but it sounds like this is as-intended.