Sagarika,
Yes.But With out stock in inventory, how can we consume the material from warehouse.So here they want to have minimum stock at any point of time for this equipment.So You can have a purchase order to build the stock or as per K.Jogeswara rao garu suggestion you can upload initial stock with movement type 501 movement type.
BOM in plant maintenance helps engineers to have selection of required material of technical object at the time of maintenance order process.This also helps to have detailed parts list and qty of materials in each technical object for planning purpose.
Initially while assigning BOM to technical objects , user has to assign the qty of each component.So that system gives the BOM with qty against each technical objcet.
Even we can have restriction at the time of consumption of components against maintenance order not more than the assigned qty.(I.e not to be issued more than the qty of BOM assigned).
This validation normally helps to avoid local stores concept.
Hope this may help you.
Regards,
Pardhu