A big headache in SSAS, especially when dealing with a large cube, is making a change that when deployed, causes a cube to become unprocessed, forcing you to do a full process so the cube is usable.  Nothing is worse than making a change without realizing it will cause the need for a full process on all the partitions of a cube that will take many hours.

For example, a process full on a dimension will cause cube/measures group/related partitions to become unavailable/unprocessed.  Here are other actions that will make your cube unprocessed:

• New measure group
• New measure
• Edit measure aggregation method
• Edit dimension usage

Here are other actions that will make your dimension unprocessed (and therefore all cubes connected to the dimension become unprocessed):

• Add an attribute to a dimension
• Change the order by property of an attribute
• Edit the attribute relationship
• Add or delete dimension translation

So, make sure you understand which changes will cause an unprocessed state which makes the cube unusable so you can do it off-hours so you don’t end up getting angry phone calls that the cube is not working!

More info:

SSAS: Which change makes the cube/dimension unprocessed?

Processing Analysis Services Objects

Cube “Process State” changing to UnProcessed