Hi,
From the costing point of view:
1) Create a project along with WBS for maintenance of Plant.
2) Assign budget & release the same on WBS.
3) Create maintenance order using t-code IW31 and assign WBS/Network as account assignment
4) After this settle all your maintenance actuals using KO88 and there you can use WBS/Asset/Cost center as settlement receiver.
Also Google PS-PM integration, you can find lots of threads.
Regards
Shishir