Plant 1 and Plant 2 are different locations in NetSuite, I suppose, right? If so, in the end a work order in Plant 2 will generate a need of materials to do production. You can handle it in different ways, depending on the modules you have:
• Simply having the WO in Plant 2 generate a back order, therefore doing a manual Inventory Transfer/Transfer Order to move the needed goods from Plant 1 to Plant 2
• Using the DRP that’s included in the Demand Planning module, defining that Plant 2 will be restocked by Plant 1 for the components, in that case the “Replenish Location by Transfer Order” screen will automatically suggest (and generate) the TOs to move the goods between Plant 1 and Plant 2
• Using the MRP that’s included in the Demand Planning module, setting up a Rule Group that define that for those goods (for example using a Planning Item Category) Plant 2 will be replenished by Plant 1
PROs and CONs? Option 1 comes without the need of Demand Planning, but it’s a lot more manual (you need to identify from a report what and how much you have to transfer and then generate either manually either through a CSV import the Inventory Transfers/Transfer Orders). Option 2 and 3 require Demand Planning, but are a lot more efficient from process perspective. The difference between option 2 and 3 is that the first one is not a time planning (so you won’t transfer the goods only just before you need them, but instead as soon as you create the WO in the Plant 2, even if the WO is to be built in 3 months), while option 3 requires a bit more of manual set-up and maybe is too much for what you actually need