Overview
When Logiwa IO suggests a putaway location, it doesn't only look at the stock already there. It also counts space that has just been suggested to other operators who haven't finished putting away yet.
This is soft allocation: suggested space is held for a short time, so two people aren't sent to fill the same gap. It's always on in directed putaway; there's nothing to set up.
How it works
Every time directed putaway suggests a location, a putaway session is opened in the background. It reserves that location for the quantity or LP being put away. Other putaway suggestions treat the reserved space as already filled. Operators don't see sessions; they just stop being sent to space someone else is about to use.
Putaway type | Reservation starts | Lasts | Released when |
Product (Bulk / one-by-one) | Each time a location is suggested | 15 minutes from the last suggestion | The transfer is done (any quantity, any location), or it expires |
LP | Each time a location is suggested. Scanning the same LP again replaces its earlier reservation | 15 minutes from the last suggestion | The LP is transferred, or it expires |
LP (Sequential) | When the parent LP is scanned, for up to 20 child LPs | 60 minutes, restarted on every transfer, skip or Suggest Another | Each child LP as it's transferred; the rest when the session is completed, abandoned or expires |
For the algorithm, a reserved location is treated as if the reserved stock were already in it. So almost every action that looks at what a location holds sees the reservation: empty-location, same SKU, same lot or dates, same client or product group, capacity, capacity mode, SKU count and volume checks. Actions that only look at the location itself, such as its zone, group, type or aisle, aren't affected.
Putaway only counts putaway reservations, not open replenishment tasks. Replenishment has its own setting; see Understanding Soft Allocation in Dynamic Replenishment.
Scenarios with real algorithm set-ups
1. Topping up pick faces with capacity
Algorithm
Rule 1 — Actions: Suggest a location that has the same SKU, Check Location Capacity. Order by: Walking Path Priority.
Set-up: Pick faces A-01 and A-05 both already hold SKU-1. A-01 has a product capacity for SKU-1 with room for 30 units; A-05 has room for 40. A-01 ranks first.
What happens:
Operator A scans 20 units of SKU-1 and is suggested A-01 (room 30 → 10 left after the reservation).
Operator B scans another 20 units of SKU-1. A-01 only has 10 left, so operator B is suggested 10 to A-01 and 10 to A-05.
Without soft allocation, both would have been sent to A-01 with 40 units for 30 units of space.
2. Pallets into empty rack positions
Algorithm
Rule 1 — Condition: LP Type = Pallet. Actions: Suggest a location with the selected location group = Pallet Racking, Suggest an empty location. Order by: Walking Path Priority.
What happens:
Two forklift drivers receive pallets at the same time.
Driver A scans PAL-100 and is suggested empty position R-12.
Driver B scans PAL-200 seconds later. R-12 is still physically empty but reserved, so driver B is suggested R-13. Neither driver arrives to find the other's pallet in the way.
3. "Same SKU first, otherwise empty" with two operators
Algorithm
Rule 1 — Actions: Suggest a location that has the same SKU. Order by: Walking Path Priority.
Rule 2 — Actions: Check Product Group & Location Zone Match, Suggest an empty location. Order by: Walking Path Priority.
What happens:
Operator A puts away a new SKU that isn't stored anywhere. Rule 1 finds nothing, so Rule 2 suggests empty location Z-04 in the zone matched to the product's group.
Operator B puts away a different new SKU from the same product group. Z-04 is reserved, so it no longer counts as empty: operator B is suggested Z-05.
Operator C puts away the same SKU as operator B. Because Z-05 is reserved for that SKU, Rule 1 suggests Z-05.
4. Volume-based shelving
Algorithm
Rule 1 — Actions: Configure Volumetric Putaway, Suggestion Strategy: Fit Entire Putaway Volume. Order by: Location Empty Volume.
What happens:
Shelf V-22 has 500 cm³ of free volume.
Operator A's LP needs 350 cm³ and is suggested V-22.
Operator B's LP needs 200 cm³. V-22 is now treated as having 150 cm³ left, so operator B is suggested another shelf.
5. Putting away straight from receiving
Algorithm
Rule 1 — Condition: Is Receiving Process. Actions: Suggest a location with the selected location group = Overflow, Suggest an empty location.
Rule 2 — Actions: Suggest a location that has the same SKU, Check Location Capacity.
What happens:
Receiver A uses Suggest Putaway Location on the Receiving screen. Rule 1 applies because this is putaway straight after receiving, and empty overflow location O-01 is suggested.
Receiver B does the same a moment later for another product and is suggested O-02, because O-01 is reserved. Putaway done later from the directed putaway screen skips Rule 1 and uses Rule 2. Reservations made from receiving count exactly like those made in directed putaway.
When operators change course
These examples use the set-up from scenario 1 (A-01 has room for 30).
What the operator does | What happens to the reservation |
Is suggested 20 for A-01, puts away only 12 | The whole reservation ends with the transfer. A-01 has 12 more units in it; the space for the other 8 is free |
Is suggested A-01, but puts away in A-07 (Force Suggested Location off) | The reservation ends with the transfer, so A-01's space is free again straight away |
Is suggested A-01, taps Suggest Another | The reservation moves to the new location; A-01 is free for the next operator |
Is suggested A-01, then leaves for another job | A-01 stays reserved until the reservation expires (15 minutes), even though it's physically half-empty |
Scans the same 20 units of SKU-1 twice | Each product scan adds a new reservation, so A-01 now looks full and the second scan is split or sent elsewhere. The extra reservation clears when it expires. Scanning the same LP twice doesn't do this: the new reservation replaces the old one |
Sequential putaway
Situation | What happens |
Operator A scans CART-7 (12 child LPs) a minute before operator B scans CART-9 (8 child LPs) | CART-7's 12 suggested locations are reserved first. CART-9's LPs only get space that's left after those reservations |
Operator B puts one of CART-7's LPs away with the regular (Directed LP Putaway) option | That LP's reservation moves to operator B. The other 11 stay with CART-7, whose queue skips the moved LP |
Operator A skips an LP | Its reservation stays; the LP moves to the end of the queue |
Operator A abandons the session | All remaining reservations are released immediately instead of waiting 60 minutes |
What to expect
Locations look full sooner. Space counts as taken as soon as it's suggested, so with many operators working at once, "no location found" can appear earlier than the physical stock suggests.
Empty locations get used up faster. A reserved empty location no longer counts as empty.
Suggest Another offers fewer options while other operators hold reservations nearby.
Common questions
Can I turn soft allocation off for putaway? No. It's always on in directed putaway.
Does it change inventory screens or reports? No. Reservations are only used when choosing a location. Screens and reports always show physical stock.
Can I see or clear reservations? No, they're managed automatically. For sequential putaway, abandoning the session releases all its reservations at once. See Managing a Sequential Putaway Session.