Understanding Material Requirements Planning

Use the MRP- Gross Regeneration version of MRP/MPS Requirements Planning to produce a single-facility MRP planning schedule for the items that you select. Alternatively, you can use the MRP - Net Change version of MRP/MPS Requirements Planning to produce a single-facility MRP planning schedule. You can generate a material requirements plan for:

• A single item.

• All items.

• Only items that are affected by transactions since the last generation.

When you generate a material requirements plan, the system evaluates selected information, performs calculations, and recommends a time-phased replenishment plan for all selected items. MRP regeneration uses the same programs as DRP/MPS regeneration.

MRP output consists of information in the time series, action messages, and pegging. Use the time series information to decide whether to accept the planning that is suggested by the system or to override it. You should review the action messages for individual item numbers to determine which action, if any, you need to take. Use pegging to identify parent demand for components.

MRP runs most effectively when you ensure the accuracy and validity of the planning information listed in this table:

Planning Information	Description
Master schedule	Ensure that the master schedule is at least 95 percent accurate. Accuracy is measured by comparing the creation of an end product to the performance of the schedule.
Bill of material	Ensure that the bill of material is at least 98 percent accurate and contains the correct components and quantities. Accuracy is measured by comparing how the item is built in the factory to the correct components and quantities that are contained in the bill of material.
Inventory	Ensure that the inventory count is at least 95 percent accurate. You achieve this accuracy through the cycle count process.
Lead times	Ensure that the lead times are valid. The system provides planned lead times. In runtime, the actual time to complete an order can vary.