SAP B1 Reorder Point, Safety Stock and EOQ Calculator
SAP Business One can plan with minimum inventory levels, lead times and order multiples, but it will not tell you what those numbers should be. This calculator derives them from demand variability, lead time and service level, then adds EOQ for a sensible order quantity.
Your numbers
Calculate from at least 3 to 6 months of issue history.
Your results
Statistical estimates. Validate against real demand history, supplier reliability and minimum order constraints before changing planning data.
Safety stock and reorder point versus lead time
Sweeps Supplier lead time from 1 to 90, holding your other inputs fixed.
Compute planning values for every item
Optional help deriving safety stock and reorder points from your SAP Business One transaction history.
Optional. The tool and every export work without this. No spam.
How to use it
Pull a few months of issues for the item and compute the average and standard deviation of daily demand. Enter the supplier lead time you actually experience, not the quoted one. Pick a service level that fits the item's importance. Then read safety stock, reorder point and EOQ, and key the results into the item master Inventory and Planning tabs.
The formulas
Safety stock = Z x sigma x square root of lead time, where Z comes from the normal distribution for your service level. Reorder point = average daily demand x lead time + safety stock. EOQ = square root of (2 x annual demand x order cost / annual holding cost per unit). The chart shows how both safety stock and reorder point grow as lead time stretches.
- Z is about 1.65 at 95% and 2.33 at 99%
- Safety stock grows with the square root of lead time
- EOQ is insensitive to small input errors
Where the numbers go in SAP Business One
In the item master, the Inventory Data tab holds minimum and maximum inventory levels by warehouse, and the Planning Data tab holds procurement method, lead time, order multiple and minimum order quantity used by the MRP wizard. Check field names in your version, as screens differ slightly between releases.
Common mistakes
Using forecast error instead of demand deviation, ignoring supplier lead time variability, setting one service level for every item, and treating EOQ as binding when the supplier has pack sizes or price breaks. Review A items monthly and C items twice a year.
Frequently Asked Questions
Should reorder point be the minimum inventory level in B1?
Many teams use it that way for items bought on a reorder-point basis, because a shortfall below the level flags a need. Items driven by MRP from demand often use a smaller safety level instead, so choose per planning method.
What if lead time varies a lot?
This model assumes constant lead time. If supplier lead time varies, combine both variances: safety stock uses the square root of lead time x demand variance plus demand squared x lead time variance, all multiplied by Z.
Why is EOQ so different from my minimum order quantity?
EOQ balances ordering and holding cost only. Supplier minimums, packaging, price breaks and shelf life override it. Use EOQ as a reference point, then round to the practical order multiple.
How often should I recalculate?
Recalculate A items whenever demand or lead time shifts noticeably, and at least quarterly. Lower value items can be reviewed twice a year if their consumption is stable.
If you want these values computed for every item straight from your B1 history, Netray can set that up. The calculator stands on its own.
Related Tools
SAP Business One License and 5-Year TCO Calculator
Enter professional and limited user counts, prices from your quote, maintenance and services ratio to see total cost of ownership over your horizon.
SAPSAP B1 Inventory Valuation Method Comparison Calculator
Enter two purchase layers and a sale quantity to see cost of goods sold, margin and remaining stock value under moving average and FIFO.
SAPSAP B1 Landed Cost Allocation Calculator
Spread shipment charges across the goods by value share to see landed cost per unit and the uplift over invoice price before you post a landed cost document.
SAPSAP B1 Warehouse Bin Location Capacity Planner
An editable worksheet to list bin codes, dimensions and fill factor, compute usable volume and plan bins before you load them into a B1 warehouse.
More SAP tools
See all- SAP Business One Production Order Checklist
- SAP B1 Item Master Import Template (DTW)
- SAP B1 MRP Setup Readiness Assessment
- SAP B1 Implementation Cost Calculator
- SAP Business One Go-Live Readiness Checklist
- SAP Business One Implementation Project Charter Template
- SAP Business One BOM Cost Rollup Worksheet
- SAP Business One Cycle Count Variance Worksheet
- SAP B1 Production Order Cost Variance Calculator