Dmitry,

>Thank you for giving an example of a composite object. Sounds very sophisticated. In my case, the object will somewhat simple. For example, "Equipment Object", "Work Order Object", etc.

I'd suggest that whatever you decide that you try it on for size in at least a mockup of a system with a couple of BOs and see how well it works for you. Don't be afraid to scrap the first couple of attempts if it all doesn't fit together as well as you want it to. In general it takes about 3 generations of class design before you get it really right.