Dear Mr. Raveerote Khoonta,
1. Based on the SAP configuration, it could be 1 PR for 1 work order. Or 1 PR for 1 material item; 1 PR for 1 Service operation (if the Collective Requisition NOT selected).
2. We can have several items in 1 PR. Each item can be linked to different vendors and different Purchase Orders. You can use just 1 work order in this situation. Don't worry about the PRs.
Regarding the INOP, package is used to group work orders for planning and scheduling. The package has no relationship to PR.
Please don't hesitate to contact me if you need more information or support.