Dimensional Hierarchy

I have a question about dimensional hierarchies:

If I have a dimension, with attributes,

-Type
--Size
---ID

Could Size be look at as a whole regardless of Type if it falls a level below Type in the hierarcy?

Assuming they are simply dimensional attributes, then sure, they can be used independently. Wither you are using relational tables or cubes, there is no reason you could not look at things by size regardless of type.

In what scenario would this not work? Just so I know I am asking the right question.

Offhand, I can't think of one...