How do I optimise the supply side of my operations?
Six free calculators that answer the working questions of inventory planning, one at a time — how much to hold, when to order, how much to order, what a stockout costs, how fast stock moves, and which items matter most. Plain-English answers, standard methods, your numbers.
Safety Stock
BufferHow much cushion to hold against demand swings and late deliveries — enough to stop firefighting stockouts without tying up cash in stock you don't need.
Reorder Point
ROPWhen to place the next order so stock lands before you run out — your lead-time demand plus the buffer, turned into a trigger level.
Economic Order Quantity
EOQThe order size that keeps ordering and holding costs lowest overall — no bleeding money on too-frequent small orders or cash tied up in bulk buys.
Stockout Cost
RiskWhat one out-of-stock period actually costs you in margin and expediting — the reality check on whether your buffer is too thin or too fat.
Turnover & Days of Supply
VelocityHow fast stock moves and how many days your current inventory lasts — your read on whether the chain's numbers are working in practice.
ABC Classification
PriorityWhich items deserve the tightest control, ranked by annual value — so you run the full chain on the items that actually move the money.
Moving what you ordered
Once you know how much to order, the next question is how to move it. Freight-per-unit and truck-load economics live on jit.delivery, the sister toolset for the delivery side.
How the tools connect
The first four tools run in order, each handing its result to the next. You start on the safety stock tool, sizing the buffer that absorbs the swings in your demand and the wobble in your lead times. That buffer feeds straight into your reorder point — your lead-time demand plus the buffer — which is the on-hand level that should trigger a fresh order. Knowing when to order, you then work out how much: the economic order quantity tool sizes the lot that keeps ordering and holding costs lowest together. And because getting any of those wrong has a price, the stockout cost tool puts a rupee figure on a single out-of-stock period, so the buffer you chose can be weighed against what a shortage actually costs you.
The other two tools don't sit in that line — they read the picture from the side. Turnover & days of supply is the scoreboard: how fast your stock moves and how many days your current inventory would last. ABC classification is the triage: it ranks your items by annual value so you know where to spend planning attention, and which items are even worth running the full chain on. Use them to check whether the numbers the chain gives you are landing where you expect.
None of these is a one-time answer. Demand shifts, suppliers change, and your own costs move — so treat each result as a starting number to revisit with your own figures, not a setting you lock once. outofstock.in is built and maintained by an independent supply-chain practitioner — more on the About page.