Hello ,
The purpose for long time planning is to carry out an annual planning or quarterly planning run you require information on the future stock and requirements situation. This means you need to know how sales and operations planning influence resources. You are using Re-order point, then there is no need to use long term planning, In LTP first you simulate and then active the operative planning, so no question of Re-order point in LTP.
I hope this information helpful to you,,
Thanks & Regards
Umesh Mali