Hi Anthony
You have to create it for a planning plant. But what is not very well now but a feature which helps the case you describve is centralised task lists. Create tasks lists for one plant and convert the work centers, storage locations etc, by using a minor enhancement depending on the main work center of the functional location/equipment/order header...
But be mindful, this is useful if there is standard way of working, similar maintenance work centers exist in different plants... Then you maintain one Task List and during th ecreation of the order, the work centers of the task list is replaced with the work centers of the site which the order belongs to. It was first introduced for IS-A&D and IS-DI but now it is available for standard SAP ECC.
Usage of Central Task Lists in PM/CS Orders - Maintenance Planning - SAP Library
Regards
Savas