Is OB useful in Trade union understanding ?

I have been thinking very deeply for few days that whether principles of OB are applicable in TU or not ? Finally, I find that if we consider TU as a tool for only collective bargaining, very few principles of OB may work here. In that case we can limit our understanding on basic concept of leadership, work motivation etc. But to me TU can not be considered in terms of power metaphor it is more than that. Can we consider it as open system like the biological system ?