Dynamics NAV gives us the option to run Regenerative or Net Change MRP Planning (NAV Planning Worksheet).
The question is: Which one should you use?
From the APICS Dictionary:
Regenerative MRP: An MRP processing approach where the master production schedule is totally re-exploded down through all bills of material, to maintain valid priorities. New requirements and planned orders are completely recalculated or “regenerated” at that time. Ant: net change MRP.