1) Net Requirement Calculation
2) Lot-Size Procedures / Calculation
3) Procurement Types / Proposal
4) Scheduling
5) BOM Explosion
1) Net requirement calculation
- A comparison of firmed receipts & requirements takesplace along time axis.
- If a material shortage occurs then the system calculatesa net requirement.
- Available Qty is Stock-Safety Stock.
- Net requirement = Total requirement - Avail Qty.
- You can define the available part of the safety stockin a MRP group.
- New order proposals are not created until stock levelshave fallen below the available portion of safety stock
2) Lot size Procedures
There are 3 Lot sizing procedures in SAP R/3 Static, Periodic& Optimum lot sizing.
a) Static lot sizing
Lot-to-lot order quantity
Fixed lot size
Replenish up to maximum stock level
b) Periodic lot sizing
Daily lot size
Weekly / Monthly lot sizing
Flexible periods according to planning calendar
c) Optimum lot sizing
Part period procedure
Least unit cost procedure
Gross reorder procedure
Dynamic lot size creation
-Net requirements are used in lot size calculations todetermine the quantities of the individual order proposals
-For period or optimum lot-sizing procedures, severalnet requirements are clubbed together in one order proposal.
-Lot sizes can be restricted by using options
-Define maximum or minimum lot size
-Rounding value functions
3) Procurement types
- Procurement types define whether a material is producedin-house or procured externally.
- If the procurement type is E then the system alwaysuses in-house production time.
- If the procurement type is F then the system alwaysuses Planned delivery time
- All other types of procurement like stock transfer,sub-contracting, production in other plant are carried out using specialprocurement key.
- Procurement key & special procurement key are availablein MRP-2 screen of material master.
4) Scheduling
Backward Scheduling
- The goods receipt processing time specifies the numberof workdays required by the stores person to check the material received& to place it in stock.
- In-house production time is calculated by adding leadtime & the floats before & after production.
- The opening period represents the processing time requiredby the MRP controller for converting the planned orders.
Forward Scheduling
- The system schedules forward starting from the basicstart date.
- "today" scheduling: The system carries out forwardscheduling using the current date as a basic start date.
5) BOM explosion
- In BOM explosion, the system calculates the componentsor assemblies required for the appropriate BOM
- The key date for evaluation of the BOM (Explosion date)is the order finish date of the planned order
- Using the lead time offset in the BOM you can displacethe dependent requirements date of a specific component.
