SCOM Two Overrides Applied, who wins?

Question

I have a question regarding overrides with SCOM 2012.  Let's say there is a Logical Disk Space monitor in place that has a threshold of 10%.   I have a group created which contains a certain subset of logical disks.   Lets say I
override my Logical Disk Space monitor and set the threshold to 5% for only that group.   Now, six months later, someone comes along and says, just for this one specific server, override the threshold to be 2%.   This one server is in the
group above, that we previously set to 5%.  So which override wins for that one server?  Does it go based on the date, or order,  the override was applied?   Because both sets of overrides are still in place.  I just don't know
how SCOM decides which to listen to.
Hopefully that made sense.  Let me know if you need any more information, otherwise thanks in advance for your help!

Answer 1

There are some rules that go along with how they get applied.
Now, how do all these overrides actually get applied? To take the most complicated case, we'll work with an instance. We want to know what overrides apply to a particular instance of IIS for a particular rule targeted toward IIS. The first thing the algorithm
does, conceptually, is gather all the types and instances that are in this instances hierarchy. So, this instance would include the IIS class and any classes that it derives from all the way to System.Entity and the computer instance that hosts this IIS
instance and the computer class of this computer as well as all it's base classes. Next, the algorithm collects any overrides that may apply to this particular rule and overlays them on the hierarchy. So, if you have an enabled override disabling this rule
with a context of System.Entity, it will exist in this objects hierarchy. With this conceptual hierarchy in mind, the algorithm starts at the top and traverses down applying the following criteria, in priority order:
Non-Category enabled overrides always win over category overrides
An enforced override always wins over a non-enforced override
Instance targeted overrides always win over class targeted overrides
Overrides in non-sealed management packs always win over sealed overrides
A child in the hierarchy of overrides always wins over a direct parent override of the same type (instance vs class)
Class overrides from contained instances always win over class overrides of the instance.
Instance overrides with the higher relative depth win over those with a lower depth. Depth is calculated from the root node(s) of the containment hierarchy of which the instance in question is a part
Randomly chosen
Taken From http://blogs.msdn.com/b/jakuboleksy/archive/2006/12/06/overrides-in-scom-2007.aspx
and I found it to hold water