Which of the following is the most critical driver of poor material planning when using an MRP system?
1) MRP Planner fails to maintain accuracy of the BOM or internal/purchased lead times
2) MRP Planner fails to keep track of difference between cycle stock and safety stock
3) MRP Planner fails to release purchase orders or production work orders
4) MRP Planner fails to inform MPS Scheduler of part delays and expediting success/failure
5) All of the above