In short
- This week: check what's still in transit against your promotion list, take constrained lines out of the discount, and agree backorder rules before the first order lands.
- During peak: review replenishment signals every day, protect your A-products first, and keep backorders visible with a hard time limit.
- Advanced: feed promotions straight into your forecast, check incoming stock against warehouse capacity, and let aged backorders escalate automatically.
- After peak: move excess stock into a clearance plan before it turns into dead stock, and review the season while the details are fresh.
Why peak season inventory management is different from day-to-day replenishment
Regular replenishment tolerates small errors. A reorder point that's a few days late costs you a bit of availability, and you correct it on the next cycle.
Peak season doesn't give you that room. Demand moves faster than your correction cycle, and suppliers are managing their own peak on top of yours. A stockout on a hero product during Black Friday week costs a lot more than the same stockout in March.
Delivery can decide whether a sale happens at all. DHL's 2026 E-Commerce Trends Report surveyed 29,000 shoppers in 29 countries and found that 67% have abandoned a purchase over the delivery offer alone, whether that was cost, speed or not knowing when the order would arrive. During peak, more shoppers than usual run into exactly that.
What can you still fix in the week before Black Friday?
Most of the big decisions, like forecasts, order quantities and shipping methods, were made weeks ago. Our guide to seasonal buying mistakes covers that planning. This week is about checking that the plan still matches reality.
Check what's still in transit
Go through every open purchase order for the products you're promoting. Anything that hasn't shipped yet, or is on the water with an arrival date after Black Friday, needs a decision now: expedite it, substitute it in the campaign, or accept that the line will sell out.
A system that tracks each supplier's real delivery reliability, rather than the lead time on their price list, flags these orders for you instead of leaving them for someone to spot on Thursday night.
Match the promotion list to your stock
Get the final list of products marketing is pushing and check it against stock on hand plus confirmed incoming. A discount on a line you can't restock in time turns into stockouts and cancelled orders during the exact week you most need to look reliable.
If a supplier you depend on can't handle a spike, take their products out of the deepest discounts. It's an easier conversation now than on Saturday.
Agree your backorder rules before the first order lands
Decide now how long a backorder may stay open before someone acts, and what that action is: expedite, substitute or message the customer. Peak week is the worst time to make that call order by order.
How do you manage inventory while peak season is live?
This is where most teams lose control, even with a solid plan, simply because nobody keeps checking it once the season starts.
Watch replenishment signals every day
A weekly review that works fine in March is too slow from Black Friday through Christmas. Sales velocity, lead times and supplier capacity can all shift inside a single week.
An automated replenishment system checks these signals every day by default. If you're doing it by hand, move your highest-priority SKUs to a daily check at minimum.
Protect your A-products first
Not every SKU deserves equal attention once peak is live. If you haven't run an ABC analysis yet, a quick one on last year's November and December sales still tells you where to look first.
Put your tightest safety stock buffers and closest monitoring on your A-products. Automated tiering adjusts those buffers as sales velocity shifts, instead of leaving them where they were set in October.
Keep backorders visible and time-boxed
Backorders are normal during peak season. The damage comes from a backorder that sits for weeks because nobody set a limit on how long it can run. Apply the rule you agreed before Black Friday, and check the list daily.
Koopjesdrogisterij cut backorders by 40% and reduced inventory by 32% after moving 94% of purchasing onto automated replenishment, shrinking a team of three buyers to one. Martijn Alserda, their Head of Purchasing, put it directly: "Three buyers used to spend almost their full days placing orders. Now that 94% of the process is automated, one person can handle it all."
Know your supplier's real capacity
A supplier's standard lead time gets much less reliable once they're handling peak volume from every customer at once. Ask what their capacity looks like for the December restock, and feed the real number into your system so every order suggestion accounts for it.
Three advanced tactics once the basics are covered
These three are only possible once purchasing runs through a system that acts on live data, and they matter most in the weeks your team has the least time.
Feed planned promotions into your forecast before the spike
A forecast built on history doesn't know you're launching 40% off on a specific line this Friday. It only sees the spike once it's happening, and by then the reorder is late.
A promotions input lets you set the expected uplift directly, say a 100% increase, together with a longer reorder period (how often the system places a new order) to bridge a purchasing cycle that runs slower during peak. If you're running a Cyber Monday or December campaign after Black Friday, there's still time to set it up for those.
Check warehouse receiving capacity against incoming goods
It's easy to plan around what you'll sell and forget to check whether your warehouse can receive that much stock in the week it lands. A forecast can look fine on paper and still produce a week where 45,000 units are due in against a team that can process 30,000.
Smoothing fixes this without cutting volume: gradually extend the reorder period for your priority tiers so the same total arrives across a curve your warehouse can absorb, and leave the lead time itself untouched.
Let aged backorders escalate automatically
Set a rule so that once a backorder passes its age limit, and the margin still justifies it, it converts into an expedited order (faster, at a higher cost) with an alternative supplier. That policy runs every day whether or not anyone checks it.
Peak season inventory management by phase
Here's how the four phases compare side by side:
| Phase | Focus | Risk if skipped |
|---|---|---|
| Final week before | In-transit check, promo list vs stock, backorder rules | Promoted products sell out on day one |
| During | Daily signal checks, A-product priority, time-boxed backorders, real supplier capacity | Small delays compound into stockouts you notice too late |
| Advanced | Promotion-aware forecasting, warehouse capacity smoothing, automatic backorder escalation | Manual monitoring breaks down in the weeks your team has no time |
| After | Clearance plan for excess stock, structured review | Excess turns into dead stock, and the same mistakes repeat next year |
Illustrative summary, not tied to a specific customer's results.
What should you check once peak season ends?
Move excess stock into a clearance plan before it becomes dead stock
Stock that didn't sell over Black Friday and December becomes a real problem once it sits into the new year with no plan. Set a clearance window and a markdown trigger while the season is still running.
A system tracking sell-through in real time flags slow movers while there's still time to act. Otherwise excess stock quietly turns into dead stock while everyone recovers from the rush.
Review the season while the details are fresh
Which supplier ran late, which discount backfired, which SKU needed a bigger buffer: these details fade fast. Capture them in early January and feed them straight into next year's purchasing process.
Turn peak season into a system you can trust
Peak season inventory management is hard for one reason: someone has to keep watching the plan while everything else is also demanding attention.
Optiply's supply chain agent does that watching for you. It checks replenishment signals daily, applies promotion uplifts when you tell it one is coming, smooths incoming goods against warehouse capacity and escalates aged backorders without anyone having to remember. Your team's attention goes to the exceptions that need a person.
If your peak season plan tends to fall apart somewhere between the forecast and the fulfilment, book a demo and we'll show you how to keep it on track through December and into next year's peak.
Frequently asked questions about peak season inventory
How often should you review inventory during peak season?
Every day, at least for your A-products. Weekly reviews that work during normal cycles are too slow once demand, lead times and supplier capacity all shift inside the same week.
Should you discount products that are already supply-constrained during peak season?
No. Discounting a line your supplier can't restock in time creates a demand spike you can't fulfil, which leads to stockouts and cancellations rather than extra revenue.
What's a reasonable backorder limit before it starts costing you sales?
There's no universal number. Set a maximum age for any backorder before it automatically triggers an escalation, whether that's expediting, substituting or contacting the customer.
Can automation really replace manually watching inventory during peak season?
Automation handles the watching. A system can check replenishment signals daily, apply a promotion uplift or escalate an aged backorder without anyone remembering to. Judgement calls still need a person: a supplier relationship decision, an unusual demand pattern, or whether a discount is worth the risk.
What should a post-peak inventory review cover?
Which suppliers ran late and by how much, which discounts drove stockouts instead of revenue, which SKUs needed a bigger buffer than planned, and which excess stock needs a clearance plan before it becomes dead stock.
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