1. Material Requirement Planning (MRP) is a system of planning and scheduling the time-phased materials
requirement for production operations. If the delivery schedule for the end products is known, then
Measurement and timing of the requirements of the various lower-level work-in-process items and raw-
materials can be planned exactly by simple arithmetical calculation.
Such planning is known as Material Requirement Planning (MRP).
MRP- I : It is an inventory control system, which releases manufacturing and purchase orders at the right
time to support the master schedule. This system launches orders to control work-in-process and raw
materials inventories through proper timing of order placement. MRP-I doesn't include capacity
planning. Henceforth the terminology MRP-I and MRP will be used interchangeably.