Hi Ajay,
Well, are you trying to use PS instead of PM ?
I am not sure whether this can be incorporated in your system
PM Functionality
1. We use Functional Location / Equipment as Technical object to which we do maintenance and capture the cost.
2. We have control key PM01 - Internal Labour / PM03 - External Labour (Which creates Service Entry Sheet)
3. Materials can be issued from Stores or procured from vendor.
4. Settlement and Business Closure
PS Functionality
1. We have Project / WBS to capture the cost.
2. We have PS01 - Internal Activity/ PS02 - External Activity / PS03 - Cost Activity / PS04 - Service control keys
3. Material components can be issued from stores or procured from vendor. You can assign material to any of the above activity.
4. Settlement and Closure
Outline of both the systems look same, but the purpose of using the system is different. If you create Equipment as a WBS element in PS, still you can calculate the cost of the materials / service spend under the WBS element, using that you can settle to cost centre and stuff.
Hope you got a bit. 
Regards
Terence