Common challenges
The stock is in the building.It's just not at the pick face.
A picker reaches the location and it's empty — not because the SKU is out of stock, but because the replenishment task that should have topped it up hasn't arrived yet. The wave stalls, the picker waits or skips ahead, and the count of blocked picks climbs before anyone downstream even knows why. The fix isn't more safety stock at the face; it's replenishment sequenced against the pick that depends on it, not against a fixed round of its own.
See actual vs plan
Is this your problem?
How to tell a genuine stockout from a replenishment delay.
The two look the same from the pick face: an empty location and a picker standing in front of it. What actually separates them is what the location looked like at the start of the wave and how many picks stalled behind it once it ran dry. A location that was already empty when the wave released is a genuine stockout upstream; one that had stock at the start and ran out mid-wave, with several picks queued behind it before anyone acted, is a replenishment task that fired too late or too far down the list.
It happens because replenishment usually runs on its own clock — a threshold, a route, a fixed round — with no view of which wave is about to arrive at that location. A queue ordered by aisle or by how long a task has waited treats every open replenishment as equally urgent, so one sitting near the top of somebody's list by age can still land after the picker it was meant to feed has already stalled. The dependency between the two tasks exists on paper without being enforced on the floor.
WareBee scores your replenishment timing against a peer set matched on order profile, SKU count and footprint — never an industry median — so 'the pick face runs dry sometimes' becomes a specific location, zone or shift pattern you can act on, rather than something shrugged off at the end of the wave.
What's actually causing it
Four ways the pick face runs dry.
Each one is measured on your digital twin from data you already generate, so you can see which applies to you before the next wave releases.
Replenishment triggered too late
The task releases on a fixed threshold or round, with no view of the wave about to reach that location.
Most replenishment queues run on their own clock — a reorder point, a scheduled round — that has no visibility into which zone a wave is about to pick next. Task scheduling can instead treat a replenishment as a dependency the pick relies on, so the restock is due before the wave arrives rather than whenever its own round comes around.
Priority set by location, not by wave
The replenishment list works down by aisle or by how long a task has waited, not by which wave needs the location next.
A queue ordered by proximity or age treats every open task as equally urgent, when only the handful of locations about to be picked in the next wave actually matter right now. Sequencing replenishment by resource availability and by what the coming wave needs — not the order tasks happened to land in — puts those locations at the top instead of wherever they queued.
Replenishment competing with picking for the same people
When labour is tight, both tasks draw on the same pool, and picking against a visible order count usually wins in the moment.
A replenishment task only reads as urgent once the location it feeds is already empty, by which point picking has already had the stronger claim on whoever is free. Planning replenishment labour against the same zone pick rate that sets picking labour — rather than leaving the two to compete for capacity as it happens — is what keeps the restock from losing that argument shift after shift.
Stock present but not available in the system
The WMS shows quantity in the location, but the pallet's been moved, damaged or not recounted since it happened.
The twin checks item, location and event records against each other on an ongoing basis, so a pallet that's shifted, been damaged or gone uncounted since the last transaction surfaces as a mismatch rather than staying invisible until a picker meets it. A location can read as stocked on the WMS screen and still be exactly why a pick stalls, when what's recorded and what's physically there have quietly parted ways.
Feed the pick face before it runs dry.
WareBee's task scheduler treats replenishment as a dependency the pick relies on, not a queue running on its own clock — so a location on track to run dry during the next wave gets restocked ahead of the picker, not after. Wave timing plans replenishment labour against the same pick rate it plans picking labour against, instead of leaving the two tasks to compete for whoever's free.
Because it runs on your digital twin, you can test a different replenishment trigger or priority rule and see the stalled picks it would have prevented before anyone touches a live task list. Your team approves the sequencing change; the WMS receives it as replenishment and pick tasks in the order it already understands.
- Replenishment sequenced as a dependency the pick relies on, not a separate queue
- Wave timing plans replenishment labour against the same pick rate as picking
- Sequencing changes tested on the twin before they reach a live task list
Questions
Replenishment delays, answered.
How do I know replenishment is the constraint and not picking itself?
Compare pick-face fill at the start of each wave against how many picks stalled behind an empty location once it ran out. If locations are consistently stocked at wave release and still run dry mid-wave, with picks queued behind them before anyone reacts, the constraint is replenishment timing rather than picker speed or route — and pushing more people onto picking will not fix a restock that keeps arriving late.
What actually causes a replenishment task to fire too late?
Most replenishment runs on a fixed threshold, route or reorder point that has no view of which wave is about to arrive at that location. A queue like that treats every task as equally urgent, so a restock sitting near the top of somebody's list by age or proximity can still land after the picker it was meant to feed has already stalled in front of an empty bin.
Do replenishment and picking compete for the same labour?
Yes, in most operations they draw on the same floor headcount, and picking against a visible order count usually wins when a supervisor has to choose in the moment. A replenishment task only becomes visibly urgent once the location is already empty, by which point it is too late to have won that argument earlier — so the competition itself needs planning for, not just more hands on a shift.
What does 'stock in the building but not pickable' actually look like in the data?
It shows up as a location the WMS reports as stocked while a picker finds it empty or short — usually because a pallet was moved, damaged or miscounted since the last recorded transaction, or because it is slotted somewhere other than where the system expects it. The quantity on screen and the quantity on the shelf have quietly diverged, and nothing forces them back into agreement until someone stands in front of the gap.
What data does WareBee need to diagnose a replenishment delay?
Diagnosing a replenishment delay needs pick-face fill levels, current stock positions and replenishment task history alongside wave timing — all exports your WMS already produces, no new instrumenting required. That combination is what lets pick-face fill at wave release get compared against how often a location actually ran dry mid-wave, location by location and shift by shift. If your WMS can export a pick and replenishment event log, that's enough to start pointing at which locations and shifts are genuinely at risk of stalling a picker.
Does a corrected replenishment sequence reach the WMS, or stay a recommendation?
It reaches the WMS. Once a revised replenishment trigger or task order is approved, it goes out as the replenishment and pick tasks your WMS already runs, timed to arrive ahead of the wave that needs the stock rather than after a picker has already stalled in front of it. Only the sequencing that was actually causing stalls changes — the rest of the replenishment queue keeps its existing priority. Actuals flow back once the wave completes, so the next timing check starts from what genuinely happened at the pick face.