Supply Chain & InventoryFree calculatorPDF, Excel, Word exportInfor VISUAL

Infor VISUAL Safety Stock and Reorder Point Calculator

Safety stock in Infor VISUAL is only as good as the number a planner types into part maintenance. This calculator derives it from demand variability, supplier lead time variability and the service level you actually want, then gives the reorder point to match.

Your numbers

units/day

Average usage per working day over a representative history.

units/day

Standard deviation of daily demand from your usage history.

21 days

Order release to dock receipt, in working days.

days

Spread of actual supplier lead times. Use 0 if reliable.

$

Used to value the safety stock investment.

Your results

Safety stock
278
Quantity to hold above lead time demand.
Reorder point
1,118
Trigger quantity: lead time demand plus safety stock.
Z score
1.6449
Std deviation of demand over lead time
169.1863
Average demand during lead time
840
Safety stock in days of supply
7 days
Safety stock investment
$5,009

Assumes roughly normal demand and independent demand and lead time variation. Validate against your own history before changing planning parameters.

Save results:

Safety stock and reorder point vs lead time

Sweeps Average replenishment lead time from 1 to 90, holding your other inputs fixed.

Safety stock review from your ERP data

Optional: we can run this calculation across your parts using read-only data and return a ranked list.

Optional. The tool and every export work without this. No spam.

How to use it

Pull a few months of issue history for the part and compute the average and standard deviation of daily demand. Enter the average supplier lead time and its spread from receipt history. Pick a cycle service level, the probability of not stocking out during a replenishment cycle. The result gives safety stock, reorder point and the cash tied up. Then enter the values in the part's planning fields, such as safety stock quantity, and review them each quarter.

  • Use working days consistently for demand and lead time
  • Set lead time sigma to 0 only for truly reliable suppliers
  • Run A items at higher service than C items
  • Round up to the buy multiple or pack size

The formula behind it

Safety stock equals Z times the standard deviation of demand over lead time. That standard deviation combines two sources of risk: demand variation across the lead time, and lead time variation multiplied by average demand. It is the square root of lead time times demand variance plus demand squared times lead time variance. Z comes from the inverse normal distribution at your service level, so 95% gives about 1.645 and 99% about 2.326. Reorder point is average lead time demand plus safety stock.

Reading the chart and the result

The chart shows safety stock growing with the square root of lead time, while the reorder point grows nearly linearly because lead time demand dominates. That is why shortening supplier lead time or reducing lead time spread cuts safety stock and cash. If the days of supply figure looks very large, check for lumpy demand or a few big orders, which the normal assumption handles poorly. For those parts consider order-based planning instead of a statistical buffer.

Common mistakes

The most frequent error is using monthly standard deviation with daily lead time, which mixes units. Another is setting the same safety stock on every part, which overbuilds cheap parts and starves critical ones. Planners also forget that MRP will net safety stock against requirements, so a figure set too high inflates planned orders. Finally, do not combine a large safety stock with a large fixed order multiple for the same part without checking the combined effect.

Frequently Asked Questions

What service level should I use?

Pick by consequence of a stockout. Many plants use 95% for general parts and 98% to 99% for critical or long lead items. Each step up costs disproportionately more stock, so avoid setting everything to the highest value.

Does this replace the VISUAL planning settings?

No. It only calculates a number. You still enter the safety stock quantity in the part planning data, and MRP uses it when netting. Keep a record of how each value was derived.

Why does lead time variability matter so much?

A late shipment affects the whole demand during the delay, so its effect scales with average demand. For fast movers, lead time sigma often drives safety stock more than demand sigma does.

Can I use calendar days?

Yes, if demand and lead time both use calendar days. The key rule is consistency. Mixing working day demand with calendar day lead time understates or overstates the buffer.

If you want safety stock proposals generated across every part directly from your VISUAL data, with the query shown and a human approving changes, we can set that up.