Inventory how-to

How to handle long lead time products

Long lead time products need earlier order triggers and bigger safety stock, because you are forecasting further into the future and have less room to react to a demand spike or a late shipment.

Short answer: Long lead time products need earlier order triggers and bigger safety stock, because you are forecasting further into the future and have less room to react to a demand spike or a late shipment. The fix is mostly arithmetic: widen the reorder window and hold more cover, then check it against real sales regularly.

Why long lead times are risky

The longer it takes a supplier to deliver, the further ahead you have to guess demand correctly. A two week lead time only asks you to predict two weeks of sales. A twelve week lead time asks you to predict twelve weeks, plus whatever buffer you add for safety days. Small forecast errors get magnified over a longer window, so stockouts and overstock are both more likely.

Build in more safety days

For long lead time SKUs, increase the safety days rather than leaving the same buffer you use for fast-moving, quick-to-restock items. Safety days cover the gap between your forecast and reality: supplier delays, a sudden spike in orders, or a slow first few weeks of a new season. The longer the lead time, the more that gap can grow, so the safety buffer should scale with it, not stay fixed.

Order earlier and in bigger batches

Because the reorder point is daily sales times (lead time plus safety days), a long lead time pushes that trigger date much earlier. This often means ordering while you still have a lot of stock on hand, which can feel wrong but is necessary. It also usually means ordering bigger quantities less often, since placing frequent small orders on a long lead time adds risk without saving much.

Watch these SKUs more closely

Long lead time items deserve more frequent manual review than the rest of your catalog. Check actual sales against forecast every few weeks so you can catch a trend change early, while there is still time to adjust the next order before it ships.

Step by step

  1. List every SKU's actual supplier lead time in days, not a rough guess
  2. For any lead time over about 4-6 weeks, increase the safety days above what you use for fast-restock items
  3. Recalculate the reorder point: daily sales x (lead time + safety days)
  4. Set the order-by date early enough that the order goes out well before stock runs low
  5. Order in larger case-pack quantities to cover a longer period, since reordering is costly and slow for these SKUs
  6. Review actual sales vs forecast every 2-4 weeks for these items specifically
  7. Flag any lead time change your supplier tells you about and update it right away

Worked example

Say a SKU sells 4 units a day, the supplier's lead time is 70 days, and you set 14 safety days. Reorder point = 4 x (70 + 14) = 336 units. If you want 90 days of cover per order and currently hold 200 units with none on order, order quantity = 4 x (70 + 90) - 200 = 440 units. That order needs to go out while you still have 336 units on hand, which is a lot of stock sitting on the shelf when you hit "place order."

How SteadyShelf helps

SteadyShelf calculates the reorder point and order-by date automatically from each supplier's lead time and the safety days you set, so long lead time SKUs get flagged early without manual math. It won't tell you to change the safety days for a specific SKU based on supplier reliability history, so you still need to judge and adjust that buffer yourself based on how that supplier has performed.

$29/month flat, unlimited products and suppliers, 30-day free trial. Run the numbers now with the free reorder point calculator.

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FAQ

Should I just hold more stock on every long lead time SKU to be safe?

Only on the ones that actually sell steadily. Holding extra stock on a slow-moving, long lead time SKU just ties up cash. Focus the extra safety stock on items with consistent demand where a stockout costs you real sales.

What if the supplier's lead time varies a lot between orders?

Use your worst realistic case, not the average, when setting the lead time for the reorder calculation. If a supplier normally takes 60 days but has taken 90 days before, lean toward the higher number for safety days rather than the average.

Let SteadyShelf do this math for every SKU

Order-by dates per supplier, seasonal forecasts and draft POs for your Shopify store. $29/month after a 30-day free trial.

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