Free, in-browser. The full statistical reorder point — lead-time demand plus safety stock computed from both demand variability and lead-time variability — with pack-size rounding and a reorder-trigger check against your current inventory position. Nothing leaves your machine.
ROP = (daily demand × lead time) + z × σ_LTD σ_LTD = √(LT × σ_d² + d² × σ_LT²)
The first term is what you expect to sell while the replenishment order is in transit. The second is safety stock: the buffer sized to your chosen service level (z) against the combined variability of demand and lead time. The normal approximation assumes independent daily demand and supplier lead time. A chosen service level is a model target, not a guarantee. The trigger check compares the ROP against your inventory position (on hand + already on order), not just what's on the shelf — forgetting inbound POs is the classic double-order.
=AVERAGE(...) and =STDEV.S(...)).To evaluate how inventory signals turn into reviewed supplier orders in LineNow, bring a real item, supplier lead time, and incoming order. Compare the recommendation with your own purchasing policy and review core and add-on terms.