Putaway policy, steps and conditions

This file lists every setting of a putaway policy. It covers the policy header, every step field, and every condition (criterion). Read 00-putaway-overview.md first. It explains the order in which the system works.

Zone settings are in 02-putaway-zone-settings.md. Location settings are in 03-location-settings.md.

How to read this file

• Menu path to the screen: Sidebar > Policy > Putaway Policy. Open a policy row to get the step editor.
• Paths to code start at crates/libs/ unless they start with crates/services/.
• BASELINE means crates/libs/wms-lib-sql/sql/wms-app/migrations/001_baseline.sql.
• A line like step.rs:184 means wms-inventory/src/putaway/step.rs, line 184.
• "Stored only. It has no effect today." means: I searched all crates and no code reads the field.
• Units: the database stores weight in grams, length in millimetres and volume in cubic millimetres. The screens may show other units (for example kg). This is set per warehouse (enterprise.warehouse).
• Roles: Admin, Manager and Supervisor can create, edit and delete policies and steps. Operator and Viewer can read them. The dry run is for Admin, Manager and Supervisor only (crates/services/app-server/src/web/rpcs/putaway_policy_rpc.rs:69-93).

Contents

1. Policy header (2 settings)
2. Step fields (17 settings, plus 3 system fields)
3. Conditions (16 properties, plus the rule, the values and the attribute code)
4. Messages you can see
5. The "never runs" mark
6. The dry run

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1. Policy header

Screen: Sidebar > Policy > Putaway Policy. The list has the columns Code and Description. The header form is putaway_policy_normal_form (fields ID, Code, Description). The table is putaway_policy (BASELINE:3990).

1.1 Code

Item	Value
UI label	Code (required). Menu: Sidebar > Policy > Putaway Policy.
Column	putaway_policy.code
Type and values	Text, up to 10 characters. Must be unique in the warehouse (putaway_policy_code_key, BASELINE:11351).
Default	No default. Seed: one policy, STD (id 1), with no steps (BASELINE:8608).
What it does	It is the name of the policy. The code is the only key people use.
Affects	The policy list. The SKU form (Putaway Policy, tab Policies) and the owner form (Putaway Policy) pick a policy by code.
Example	PAL-FIFO (8 characters). PALLET-FIFO-2 is refused: 13 characters.
Interacts with	A policy can be chosen on a SKU and as an owner default. The SKU wins (see 00-putaway-overview.md).
When empty	A new policy needs a code. Empty or spaces only is refused: putaway policy code cannot be empty (wms-lib-core/src/model/policies/putaway_policy.rs, create_pipeline).
If you change it	You cannot change it. The code is read-only after creation. The public update command has no code field (putaway_policy_rpc.rs:166, struct PutawayPolicyHeaderUpdate).

1.2 Description

Item	Value
UI label	Description.
Column	putaway_policy.description
Type and values	Text, up to 60 characters. Can be empty (NULL).
Default	NULL. Seed: NULL for STD.
What it does	A free note about what the policy is for.
Affects	The policy list only. No engine code reads it. Stored for people.
Example	Pallets, FIFO, no lot mixing.
Interacts with	Nothing.
When empty	Allowed. An empty description is saved as NULL.
If you change it	The change is saved at once. It uses the policy version check (see below). Nothing else changes.

1.3 System fields of the header

Field	Column	Meaning
ID	putaway_policy.id	Row number. Read-only.
(hidden) Version	putaway_policy.version, default 1	Lock number. The update command needs the version you read. If someone saved first, you get a version conflict (return code 40) and must reload. A reorder of steps also moves this number (reorder.rs).
(hidden)	add_who, add_when, mod_who, mod_when	Audit stamps.

1.4 What happens when you delete a policy

• Deleting a policy deletes all its steps and all their conditions in one transaction.
• It is refused while any SKU or any owner default points at it.
• Message (exact form): Cannot delete: still in use by 2 items (SKU-A, SKU-B) and 1 owner (ACME) as their default. Point them somewhere else first. The message names up to 3 codes. It counts up to 50 (50+ items).
• Code: wms-inventory/src/putaway/pipeline/delete_policy.rs:97-117.
• Pallets that already have a reservation keep it. The reservation does not point at the policy.

1.5 The links to a policy (settings on other screens)

Setting	Screen	Column	Rule
Putaway Policy	SKU, tab Policies	sku.putaway_policy_id	Wins over the owner default. Empty = use the owner default.
Putaway Policy	Owner, WH Settings (owner_wh_policies_form)	owner_config.default_putaway_policy_id	Used when the SKU has none. Empty = no default.

The rule is COALESCE(sku.putaway_policy_id, owner_config.default_putaway_policy_id) (wms-lib-core/src/model/sku.rs:867-885). A pallet with SKUs from different policies is refused (see section 4.1).

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2. Step fields

A step is one rule of the policy. The system tries the steps in order of sequence. The first step that finds a location wins. The editor shows a step as three bands: Destination, Conditions, Placement. The table is putaway_policy_detail (BASELINE:4009).

A new step is live at once. It is added at the end. Message: A new step is live at once and is tried after every rule above it. A new step takes the column defaults: Suitable, Zone from the SKU, no guard, no conditions. That step already works as a very wide rule (pipeline/add.rs).

2.0 System fields of a step

Field	Column	Type and default	Meaning
Step number	step_num	Text, up to 5 characters. Unique in the policy.	Label shown as Step N (S): N is the position, S is this number. The system gives it when you add the step. It is the spelling of the sequence (10, 20, 30...). You cannot change it. Sending one is refused: Putaway step {id}: a step's number is assigned when the step is added and never ... (wms-lib-core/src/model/policies/putaway_policy_detail.rs:1000).
Order	sequence	Whole number, default 0. Unique in the policy.	The order of work. A new step gets the highest sequence + 10. Only the drag-and-drop reorder changes it (reorder.rs). The steps are read by sequence, never by step_num (step_num '10' sorts before '2').
(hidden) Version	version	Whole number, default 1.	Each step has its own lock number. Save and delete need the version you read. Two people can edit two different steps at the same time.

2.1 Mode

Item	Value
UI label	Mode. Band Destination.
Column	putaway_policy_detail.mode (enum putaway_mode)
Type and values	Suitable or Consolidate.
Default	Schema default Suitable. No steps are seeded in production. Dev seed uses Suitable (dev_only/install-db/900-dev-seed.sql:1026).
What it does	Suitable: any location that passes all checks. Consolidate: only a location that already holds (or has a reservation for) at least one product of the pallet. A product is one pair owner + SKU. The lot does not count here.
Affects	PutawayCtx.consolidate (putaway/mod.rs:928) and the rule ConsolidateRule (predicate.rs:767-848). It is the 2nd check on each candidate.
Example	Pallet of SKU W1. Location A-01-0 holds 5 cartons of W1. Location A-01-1 is empty. A Consolidate step offers A-01-0 and refuses A-01-1 with code not_consolidatable and the detail location holds nothing (no stock, no inbound reservation) — a Consolidate step requires the sku to already be there.
Interacts with	Must be empty cannot be used with Consolidate (see 2.9). The mixing rules still apply on top: Consolidate plus Mixed SKU = Not allowed means "the same SKU only, and it must already be there". A location with a reservation for the same product counts as holding it.
When empty	Not possible. The column is NOT NULL.
If you change it	Takes effect on the next suggestion. Existing reservations and stock do not change.

Values:

Value	Meaning
Suitable	UI text Any location with room.
Consolidate	UI text A location already holding this item.

Note: a pallet that stands in a location can match itself under Consolidate (predicate.rs:754-763). The engine does not skip the source location. Moving to the same place costs nothing.

2.2 Scope (where to look)

Item	Value
UI label	Five options in band Destination (no single label).
Column	putaway_policy_detail.scope (enum putaway_scope)
Type and values	ZoneFromSku, ZoneFromStep, LocationFromStep, LocationFromSku, AssignedSlot.
Default	ZoneFromSku.
What it does	It says which zone, or which single location, the step searches.
Affects	step::resolve_search_space (step.rs:517-564), called at putaway/mod.rs:956.
Example	Zone named on this step = BULK. Every candidate is a location of zone BULK.
Interacts with	Needs an anchor for two values (Zone or Location below). Database CHECK chk_putaway_step_scope_params (BASELINE:4039).
When empty	Not possible. NOT NULL.
If you change it	Next suggestion only. An anchor left from an old scope stays in the row and is ignored (inert).

Values:

Value	UI text	Meaning	Works today?
ZoneFromSku	Zone from the SKU	Search the zone in sku.putawayzone of the first line of the pallet.	Yes. If the SKU has no zone, the step is skipped (skipped:no-zone).
ZoneFromStep	Zone named on this step	Search the zone named in Zone (to_zone).	Yes.
LocationFromStep	Location named on this step	Search only the location named in Location (to_location).	Yes.
LocationFromSku	Location from the SKU	Search only sku.putaway_loc of the first line.	Yes. If the SKU has no location, the step is skipped (skipped:no-location). Most SKUs have none.
AssignedSlot	Pick location of the SKU	Search the SKU's pick locations (SKU card, tab Pick Locations), in route order.	Yes. See below.

AssignedSlot — into the SKU's pick location:

• The candidates are the SKU's pick locations, in route order (aisle, bay, level, code). Each one goes through the same checks as any candidate: blocked locations, the step's conditions, mixing, cube and weight, the reservation. The first that passes is reserved.
• The pick location's Max is always checked, with no switch: what of this SKU the location holds and is promised, plus the pallet, may not exceed Max (in the unit of the pick location). Cube and weight are checked as well; the stricter limit wins. A pallet that does not fit is not split — the next pick location, then the next step, is tried. The trace counts it as slot_max_qty.
• To choose a kind of pick location, add the condition Location type: for example Location type is Case for the case pick location.
• A pallet of several SKUs skips the step (skipped:mixed-pallet): it has no one pick location.
• A SKU with no pick location skips the step (skipped:no-slot).
• Typical use, with the condition Pallet fullness (section 3): step 1 AssignedSlot + Pallet fullness is Partial (a part pallet goes straight to picking), step 2 a zone step (the rest goes to storage).

Known gap (step.rs:496-516): for a mixed pallet, ZoneFromSku and LocationFromSku use the first line only. If two SKUs name two zones, the second SKU goes to the first SKU's zone. The dry run and the trace record this (zone_downgrade, location_downgrade).

2.3 Zone (anchor of Zone named on this step)

Item	Value
UI label	Zone (placeholder Choose a zone…).
Column	putaway_policy_detail.to_zone
Type and values	Text, up to 20 characters. Must be an existing zone code (FK fk_putaway_step_to_zone, RESTRICT). NULL allowed.
Default	NULL.
What it does	The zone to search when the scope is ZoneFromStep.
Affects	step.rs:529. Also zone_suits_temperature when Temperature is on.
Example	BULK.
Interacts with	Only read when the scope is ZoneFromStep. For other scopes the value is ignored.
When empty	With ZoneFromStep, save is refused: zone not chosen (database: Putaway step (policy P, sequence S) has scope 'ZoneFromStep' but no to_zone — that scope needs its parameter).
If you change it	Next suggestion only. You cannot delete a zone that a step names (RESTRICT).

2.4 Location (anchor of Location named on this step)

Item	Value
UI label	Location (placeholder Choose a location…).
Column	putaway_policy_detail.to_location
Type and values	Text, up to 20 characters. Existing location code (FK fk_putaway_step_to_location, RESTRICT). NULL allowed.
Default	NULL.
What it does	The single location to search when the scope is LocationFromStep.
Affects	step.rs:545, candidates.rs:594 (single_location).
Example	A-01-0.
Interacts with	The location must still pass the status, flag and type gates (see 3.x and file 03-location-settings.md). A location that is on hold gives zero candidates.
When empty	With LocationFromStep save is refused: location not chosen.
If you change it	Next suggestion only.

2.5 Guard

Item	Value
UI label	Guard (hint: hard limit on how far stock may travel).
Column	putaway_policy_detail.guard (enum putaway_guard)
Type and values	None, FromZone, FromLocation.
Default	None.
What it does	It says for which pallets the step applies at all, based on where the pallet stands now. If the guard does not match, the step is skipped. It is not a failure.
Affects	step::guard_allows (step.rs:382-388) at putaway/mod.rs:936. Trace status skipped:guard.
Example	Guard Stay in the source zone with source zone QC. A pallet standing in QC-01 uses the step. A pallet standing in DOCK skips it.
Interacts with	Needs an anchor for two values (CHECK chk_putaway_step_guard_params, BASELINE:4036). The guard column compares only the current location or its zone. A NULL anchor never matches (it is treated as "applies to nothing", not "applies to all").
When empty	Not possible. NOT NULL.
If you change it	Next suggestion only.

Values:

Value	UI text	Meaning
None	No guard (Always)	The step applies to any pallet.
FromZone	Stay in the source zone	The step applies only if the zone of the pallet's current location equals from_zone.
FromLocation	Stay in the source location	The step applies only if the pallet's current location equals from_location.

The words in the screen ("Stay in...") say "stay". The code does not keep the stock in that zone. It only decides if the step runs. Do not read it as a travel limit on the destination.

2.6 Source zone and source location (anchors of the guard)

Item	Value
UI label	Zone and Location (shown under the guard option).
Column	putaway_policy_detail.from_zone, putaway_policy_detail.from_location
Type and values	Text, up to 20 characters. Existing zone or location code (FK RESTRICT). NULL allowed.
Default	NULL.
What it does	The value the pallet's current zone or location is compared with.
Affects	step.rs:385-386.
Example	from_zone = RECV: the step runs only for pallets standing in zone RECV.
Interacts with	Only read when the guard is FromZone (zone) or FromLocation (location).
When empty	With the guard FromZone: source zone not chosen. With FromLocation: source location not chosen.
If you change it	Next suggestion only.

2.7 Ordering

Item	Value
UI label	Ordering (hint: which eligible location is offered first).
Column	putaway_policy_detail.ordering (enum putaway_ordering)
Type and values	Route or NearestToSlot.
Default	Route.
What it does	It sets the order in which candidate locations are tried. The first one that passes all checks is taken.
Affects	candidates::order_for (candidates.rs:48-58), SQL ORDER BY in wms-lib-core/src/model/location.rs:418-423.
Example	Locations A-01-0, A-01-1, A-02-0. Route order tries A-01-0 first, then A-01-1, then A-02-0.
Interacts with	A zone is not walked to the end. The system looks at at most 5 batches of 20 locations = 100 candidates per step (candidates.rs:28-32). After that the step gives up and the next step runs.
When empty	Not possible. NOT NULL.
If you change it	Next suggestion only.

Values:

Value	UI text	What the code does
Route	Pick route (code list text: Walking order (aisle, bay, level))	Sorts by aisle, then bay, then level, then code. It does not use Route Sequence. aisle is text, so aisle A10 sorts before A2. bay and level are numbers (level 0, the floor, first).
NearestToSlot	Nearest to the pick location	Sorts the zone's locations by straight-line distance (x, y, z coordinates) to the SKU's first pick location in route order, then by code. Only for a zone scope (Zone from the SKU, Zone named on this step); on any other scope Save is refused: ordering by nearness to the pick location works only when the step searches a zone. The step is skipped when the pallet carries several SKUs (skipped:mixed-pallet), when the SKU has no pick location (skipped:no-slot), and when that pick location has coordinates 0, 0, 0 — never measured (skipped:slot-not-measured). It never falls back to route order.

Note: the caption Pick route may look like it uses the location setting Route Sequence. It does not. Route Sequence is used by allocation, pick routes and task claim order. See 03-location-settings.md.

2.8 Location occupancy (one choice, three columns)

Item	Value
UI label	Location occupancy (hint: what the location may already hold). Three options: Any occupancy, Must be empty, Allow mixing, with rules.
Columns	allow_mixed_sku, allow_mixed_lot, require_empty (all boolean, nullable)
Type and values	The screen writes the three columns from one choice (wms-lib-core/src/model/policies/putaway_occupancy.rs). See the table below.
Default	Column defaults: allow_mixed_sku = true, allow_mixed_lot = true, require_empty = false (BASELINE:4026-4028). This means "no opinion".
What it does	It adds a step rule about what may already be in the location, on top of the location's own flags.
Affects	MixCheck::from_toggles (predicate.rs:129-142) at putaway/mod.rs:920. Check MixIntentRule (predicate.rs:451-651) is the 1st check on each candidate.
Example	See the three options below.
Interacts with	See 2.9, 2.10, 2.11 and the location flags Mix SKU and Mix Lot in 03-location-settings.md. A step can only narrow. It can never allow a mix the location forbids.
When empty	NULL, TRUE and "not set" all mean "no opinion" (MixCheck::None). The old NULL state was filled by migration 290.
If you change it	Next suggestion only. Stock and reservations do not change.

What each option writes:

Option	require_empty	allow_mixed_sku	allow_mixed_lot	Engine rule (MixCheck)
Any occupancy	NULL	NULL	NULL	None: no step rule. Only the location flags and lot rules decide.
Must be empty	true	NULL	NULL	RequireEmpty
Allow mixing, with rules	NULL	as chosen	as chosen	None, SameSku or SameSkuLot

Note: Allow mixing, with rules with both rows at Any writes the same three NULLs as Any occupancy. After you reopen the step it reads back as Any occupancy.

2.9 Must be empty (require_empty)

Item	Value
UI label	Must be empty (hint: mixing rules do not apply and are not shown).
Column	putaway_policy_detail.require_empty
Type and values	true, false or NULL. Only true has a meaning.
Default	false (schema).
What it does	The location must hold no stock and no container, and no other pallet may have an active reservation for it.
Affects	MixIntentRule::require_empty (predicate.rs:602-650). Uses LocBmc::is_location_occupied (location.rs:2770): stock with qty, qty_allocated or qty_picked above zero, or any container not disposed, makes the location occupied. An empty pallet still occupies.
Example	Location C-01-0 holds an empty pallet LPN. It is not empty. Code mix_intent, detail step requires an empty location; occupied=true, inbound_reservations=0.
Interacts with	Cannot be combined with Mixed SKU = Not allowed or Mixed lot = Not allowed (database CHECK chk_putaway_step_require_empty_no_mixing). Cannot be combined with Mode = Consolidate. The pallet's own reservation does not count against the location.
When empty	See 2.8.
If you change it	Next suggestion only.

Refusals:

• Save: a location that must be empty has no mixing rules.
• Save (mode): consolidating needs a location that already holds the stock, never an empty one.
• The editor hides Must be empty on a Consolidate step and says: Consolidate places onto a location that already holds this SKU, so it can never be an empty one.
• Engine (old rows): step sets mode=Consolidate together with require_empty=true: Consolidate requires the location to already hold one of the pallet's (owner, sku) identities ... so this step can never place a pallet.
• Rows saved before 2026-09-12 may still have this pair. The engine then refuses the whole policy when it loads it.

2.10 Mixed SKU (allow_mixed_sku)

Item	Value
UI label	Mixed SKU with the choices Any, Allowed, Not allowed. Shown only under Allow mixing, with rules.
Column	putaway_policy_detail.allow_mixed_sku
Type and values	NULL (Any), true (Allowed), false (Not allowed).
Default	true.
What it does	Only false has an effect. Not allowed means: after the pallet lands, the location may hold only one product (owner + SKU).
Affects	MixIntentRule::same_key (predicate.rs:534-598).
Example	Location S-01 holds SKU A. Pallet has SKU B. Result: refused with code mix_intent_sku and the detail step allows no mixing beyond the same sku; location plus pallet would span 2 identities: owner 1/sku A, owner 1/sku B.
Interacts with	The "committed" stock of a location = present stock plus the contents of every pallet with an active reservation for it (inventory_balances.rs:1718-1750). A pallet with two SKUs fails at every location, even an empty one (the pallet alone makes 2 identities). Same SKU code under another owner counts as a different product.
When empty	Any/NULL/true: no step rule.
If you change it	Next suggestion only. Existing stock stays as it is, even if it is mixed.

2.11 Mixed lot (allow_mixed_lot)

Item	Value
UI label	Mixed lot with the choices Any, Allowed, Not allowed. Shown only after Mixed SKU is decided.
Column	putaway_policy_detail.allow_mixed_lot
Type and values	NULL, true, false.
Default	true.
What it does	Not allowed (and Mixed SKU = Not allowed) means one SKU and one lot per location.
Affects	MixIntentRule::same_key with the lot compared (predicate.rs:469-472). Code mix_intent_sku_lot.
Example	Location holds SKU A lot L1. Pallet has SKU A lot L2. Refused with step allows no mixing beyond the same sku and lot; location plus pallet would span 2 identities: owner 1/sku A/lot L1, owner 1/sku A/lot L2.
Interacts with	Not allowed is only valid when Mixed SKU is also Not allowed (CHECK chk_putaway_step_mixing_executable, BASELINE:4037). The engine cannot express "one lot across several SKUs". With Mixed SKU = Not allowed and Mixed lot = Allowed, the rule is "one SKU, lots may differ".
When empty	NULL/true: lots may differ.
If you change it	Next suggestion only.

Refusals:

• Save: one lot per location needs one SKU per location.
• Screen hints: decide Mixed SKU first — mixed lot has no meaning until then; one lot never spans several SKUs — with mixed SKUs allowed, lots cannot be kept apart.
• Engine (old rows): step sets allow_mixed_lot=Some(false) with allow_mixed_sku=...: it asks for ONE LOT per location while permitting SEVERAL SKUs, and the engine has no such rule ... (step.rs:32-43).

Offered choices:

Mixed SKU	Mixed lot choices
Any	none (greyed)
Allowed	Any, Allowed
Not allowed	Any, Allowed, Not allowed

2.12 Temperature (respect_temperature)

Item	Value
UI label	Temperature (hint: a rule about the zone, not about the load). The switch reads The zone's temperature range must cover the SKU's.
Column	putaway_policy_detail.respect_temperature
Type and values	true or false.
Default	false.
What it does	When on, the step is skipped if the zone it searches does not suit the temperature of every line on the pallet.
Affects	step::zone_suits_temperature (step.rs:438-469) at putaway/mod.rs:1014 (zone scope) and :1197 (location scope). Trace status skipped:temperature.
Example	Zone COLD: min 2, max 8. SKU: min 0, max 4. They overlap (2..4), so the step runs. SKU: min 10, max 20: no overlap, so the step is skipped.
Interacts with	Reads the zone columns min_temperature and max_temperature (02-putaway-zone-settings.md) and the SKU columns min_temperature and max_temperature. An empty bound means "no limit" on that side, for both the zone and the SKU. If all lines fit, the step runs; one bad line skips it. A line whose SKU did not load counts as fitting.
When empty	Not possible (NOT NULL).
If you change it	Next suggestion only.

Important: the test is overlap, not "cover". The check is zone_min <= sku_max && sku_min <= zone_max (step.rs:458-469). The screen label says "must cover" and the readback sentence says The location's temperature range must cover the SKU's. Both words are stronger than the code and both say "location" where the code reads the zone. The dry run says "suit" (dry_run.rs:769-773), which is correct.

2.13 Fit checks (five switches)

The Fit checks row has five switches (hint: refuse a candidate that cannot physically take it). Each switch is one column. They are independent. The code reads all five together (FitToggles, space.rs:496-549). The checks run on each candidate as the 3rd check, rule CapacityRule (predicate.rs:285-425).

Common rules for all five:

• A limit of 0 or NULL means "no limit set". The check is not run, and the location is still offered. The system counts it in the trace as checks not run with the key <limit>:no_limit (space.rs:1156-1195). So an empty capacity does not block putaway, and does not protect the location either.
• The system counts stock already there plus space promised by active reservations (not yet arrived). The pallet's own reservation is not counted twice.
• If the pallet already stands in the candidate location, the check is skipped (space.rs:670).
• Oversize goods and held sections are refused before these switches, whatever you set (see 2.14).
• Important: a cube or weight limit set on the location or the zone is always enforced, whatever the switches say. The move itself (move_execute) checks location and zone cube and weight, and the zone case count, on every move (wms-inventory/src/movement/validation.rs:920-1005), so putaway checks them too and never offers a location the move would refuse (P-18). The Cube and Weight switches only decide whether a cube or weight check that could not be made (no limit set, or the pallet has no known weight) is reported in the trace. Pallet dimensions, Stacking limit and Quantity are switched on and off as before, and are not checked by the move at all.

2.13.1 Cube (fit_by_cube)

Item	Value
UI label	Cube.
Column	putaway_policy_detail.fit_by_cube
Type and values	true or false.
Default	true.
What it does	Adds the pallet's volume to what is in the location and compares with location.max_cube_capacity. If the pallet goes to another zone, it also checks putawayzone.max_cube.
Affects	space.rs:749-776 (location) and :835-840 (zone). Refusal code capacity, detail loc_cube: limit L, attempted A or zone_cube: ....
Example	Location limit 4,500,000,000 mm³ (4.5 m³). Held 3,000,000,000 + promised 0. Pallet 1,800,000,000. Attempted 4,800,000,000 is above the limit. Refused: loc_cube: limit 4500000000, attempted 4800000000.
Interacts with	The pallet volume is the sum of sku.cube × quantity over its lines. A SKU with cube 0 adds 0. Then the check cannot refuse a new pallet. The zone check runs only if the destination zone differs from the zone where the pallet stands.
When empty	A limit set on the location or zone is enforced even with the switch off. Limit 0 = no limit; with the switch on it is reported as loc_cube:no_limit, with it off it is not reported.
If you change it	Next suggestion only.

2.13.2 Weight (fit_by_weight)

Item	Value
UI label	Weight.
Column	putaway_policy_detail.fit_by_weight
Type and values	true or false.
Default	true.
What it does	Compares pallet weight + weight in the location + promised weight with location.max_weight_capacity (and putawayzone.max_weight for another zone).
Affects	space.rs:749-768, :829-834. Detail loc_weight: limit L, attempted A.
Example	Location A-02-3 limit 400,000 g (400 kg). Pallet 720,000 g. Refused: loc_weight: limit 400000, attempted 720000.
Interacts with	The weight uses one formula for all code (StockWeights). If the pallet has no known weight, the check is not run. The trace key is loc_weight:no_stock_weight. Fix it on the item or pack, not on the location.
When empty	A limit set on the location or zone is enforced even with the switch off. The switch only decides whether no_limit / no_stock_weight is reported.
If you change it	Next suggestion only.

2.13.3 Pallet dimensions (fit_by_pallet_dims)

Item	Value
UI label	Pallet dimensions.
Column	putaway_policy_detail.fit_by_pallet_dims
Type and values	true or false.
Default	false.
What it does	Checks that the pallet's footprint (length × width of the wooden base) fits the location's length × width, in either direction. Also checks the pallet's height against the location height.
Affects	space.rs:684-692, check_pallet_dims (space.rs:875-918). Details: loc_footprint: location 1200 × 800, pallet 1300 × 1100 (checked both orientations) and loc_height: location 1500, pallet 1800.
Example	Location 2500 × 1200 mm, height 1500. Pallet base 1200 × 800, height 1650 (base 150 + 3 layers × 500). Footprint fits. Height 1650 is above 1500: refused.
Interacts with	Pallet size comes from the pack: pallet_wood_length, pallet_wood_width, pallet_wood_height, pallet_hi and the height of the stacked unit. If the pack does not describe the pallet, the check is not run: loc_footprint:no_product_dims or loc_height:no_product_dims. If the location has no length/width/height (0), the trace says no_location_dims. A pallet exactly as tall as the location fits (> not >=).
When empty	See above.
If you change it	Next suggestion only. Switching it on changes which locations an unchanged policy chooses.

2.13.4 Stacking limit (fit_by_stack_limit)

Item	Value
UI label	Stacking limit.
Column	putaway_policy_detail.fit_by_stack_limit
Type and values	true or false.
Default	false.
What it does	Counts pallet positions. The capacity is location.footprint × stack limit. The pallets standing plus the pallets promised plus this one must not exceed it.
Affects	space.rs:704-727. Details: loc_positions: limit L, attempted A (the rack limit decides) or item_positions: ... (the item's own Stack limit is lower than the rack's).
Example	Location footprint 2, stack limit 3: 6 positions. 5 pallets standing or promised. This one is the 6th: fits. The next one: loc_positions: limit 6, attempted 7.
Interacts with	Stack limit = the lower of the rack (location.stack_limit) and the item (sku.stack_limit), when each is above 0. An item may lower the rack's limit, never raise it. Location Pallet positions on floor = 0 gives limit 0, reported as loc_positions:no_limit.
When empty	Switch off = not checked.
If you change it	Next suggestion only. The move does not check this limit.

2.13.5 Quantity (fit_by_quantity)

Item	Value
UI label	Quantity.
Column	putaway_policy_detail.fit_by_quantity
Type and values	true or false.
Default	false.
What it does	Compares the quantity already in the location plus the quantity arriving with location.max_qty_capacity. This is how a pick face is sized.
Affects	space.rs:732-742. Detail loc_qty: limit L, attempted A.
Example	Pick face limit 500 pieces. Holds 380. Pallet brings 150. Attempted 530. Refused: loc_qty: limit 500, attempted 530.
Interacts with	The quantity is a plain sum of all balance lines in stored units. The location limit is Max quantity on the Dimensions tab. 0 = not configured: reported, not refused.
When empty	Switch off = not checked.
If you change it	Next suggestion only. The move does not check this limit.

2.14 Checks you cannot switch off

These run on every candidate whatever the step says:

• Oversize goods (sku.positions_required above 1) need a whole free section of positions. Refusal codes: section_none (location is in no section), section_not_free, section_too_small. Detail: needs N adjacent positions of one free section (space.rs:1052-1089, predicate.rs:312-340).
• A location held for another pallet's oversize goods: code section_promised, detail held for goods spanning this section (predicate.rs:346-351).
• The zone case count (putawayzone.max_cases_count) when the pallet goes to another zone (space.rs:794-821).
• The location landing rules (the 4th check): see 03-location-settings.md.

2.15 What the readback sentence says

The step card shows a sentence, for example: Takes locations of type Case or Pick, class A, ... in zone BULK. One SKU per location. Checks volume and weight. Candidates in warehouse route order. Two gaps (found in code, putaway_step_describe.rs:1047-1066):

• The sentence names only volume, weight and pallet dimensions. Stacking limit and Quantity are never named. If only those two are on, the sentence still says Checks nothing physical — the pallet's size and weight are not compared with the location's capacity.
• The temperature sentence says "location" and "cover" (see 2.12).

---

3. Conditions (criteria)

A condition narrows a step. Table putaway_step_criterion (BASELINE:4130). In the editor, band Conditions, button Add condition (a three-question picker: Choose a property, Choose an attribute, Choose values; button Save condition). The band shows N of 16 properties used.

3.1 Two kinds of condition

Kind	Family heading	Subject (column)	What it decides
About the pallet	Product and Lot	Product	Does the step apply to this pallet at all? If any line of the pallet fails any condition, the whole step is skipped (trace skipped:product:<Property>).
About the location	Location	Location	Which locations of the search space are candidates? Other locations are never looked at.

The subject follows from the property. You do not choose it (CriterionProperty::subject, putaway_step_criterion.rs:108-128).

3.2 The columns every condition has

Field	Column	Type and values	Rules
Rule	rule (enum putaway_criterion_rule)	Include (UI is), Exclude (UI is not)	One rule per property per step. You cannot have is and is not on one property in one step.
Values	values (text array)	At least one value (CHECK chk_step_criterion_values_nonempty). Values are joined by or.	Compare exact and case-sensitive. For is: the value must be one of the list. For is not: the value must not be in the list.
Attribute code	attribute_code (text, up to 50)	Required for the 3 attribute properties. Must be empty for all other properties (CHECK chk_step_criterion_attribute_code).	One condition per property and attribute code. COLOR and SIZE are two conditions.
Subject	subject	Product or Location	Set by the system.

Uniqueness: uq_step_criterion_property on (step, subject, property, attribute code) (BASELINE:14371). Defaults: no condition exists by default. No condition is seeded.

For all conditions:

• A step with no conditions says: No conditions. Every location in scope is eligible — this step matches almost everything, so it belongs near the end of the pipeline.
• When you save, the values are checked. Closed lists (enums) accept only their own labels (see each property). Free-text values (group, class, attributes) are never checked against existing data, because a policy is often written before the items exist.
• Changing a property without sending new values is refused (see 4.4).
• Deleting a step deletes its conditions (FK CASCADE).
• Changing a condition affects the next suggestion only.

3.3 Summary of the 16 properties

#	UI label	Code	Family	Reads	Values
1	Location type	LocationType	Location	location.loc_type	enum loc_type (18 values; only 6 can be used)
2	Location status	LocationStatus	Location	location.status	Ok, Hold, Damage (narrow-only)
3	Location category	LocationCategory	Location	location.loc_category	17 values
4	Processing type	LocationProcessingType	Location	location.loc_processing_type	None, Pallet, Case, Piece
5	Location flag	LocationFlag	Location	location.loc_flag	5 values (narrow-only)
6	Location ABC	LocationAbc	Location	location.abc	A, B, C
7	Mixed SKU	MixSku	Location	location.mix_sku	true, false
8	Mixed lot	MixLot	Location	location.mix_lot	true, false
9	SKU ABC	SkuAbc	Product	sku.abc	A, B, C
10	SKU group	SkuGroup	Product	sku.sku_group	free text
11	SKU class	SkuClass	Product	sku.class	free text
12	Putaway class	PutawayClass	Product	sku.putaway_class	None, NoMix
13	Rotation	Rotation	Product	sku.rotation	Fifo, Lifo, Fefo
14	Lot attribute	LotAttribute	Lot	lot_attributes.attribute_value	free text, needs a code
15	SKU attribute	SkuAttribute	Product	attribute_value.value_text for entity_type = 'sku'	free text, needs a code
16	Location attribute	LocationAttribute	Location	attribute_value.value_text for entity_type = 'location'	free text, needs a code
17	Pallet fullness	PalletFullness	Product	computed from the pallet and its pack	Full, Partial

Code: candidates.rs:400-543 (location side), product.rs:207-278 (product side), step.rs:325-362 (gate).

A property whose stored subject is the wrong one (for example Product + LocationType) is refused when the policy loads: step uses criterion=Product/LocationType, which this build cannot execute (step.rs:326-334). SkuAttribute or LocationAttribute without a code: step's Product/SkuAttribute criterion carries no attribute_code: ... (step.rs:105-110).

3.4 Location conditions

Each narrows the candidate list in SQL (location.rs:1685-1925), so a refused location is never evaluated. The trace of a failed step (full detail) shows how many locations each property removed (criteria_removed).

All location candidates must also pass the fixed gate, whatever the conditions say: status = 'Ok', loc_flag = 'None', discard_lpn not true, and the type in the allowed set (location.rs:2140-2143).

3.4.1 Location type

Item	Value
UI label	Location type.
Column read	location.loc_type.
Type and values	Labels of enum loc_type: None, Other, Case, Pick, Pnd, Door, Pickto, Sort, SpeedPick, QC, Damage, Rtv, Destroy, Returns, Stage, Lost, InTransit, Pack. Other spellings are refused when saved.
Default	No condition. Without one, the step uses the authorized set: Case, Pick, SpeedPick, Pnd, Sort, Other (movement/validation.rs:135-148).
What it does	Narrows the types. A step may narrow the authorized set. It can never widen it. Types outside the set are dropped silently from is.
Affects	candidates.rs:107-177 and :400-445. SQL l.loc_type = ANY(...).
Example	Location type is Pick or Case: only pick faces and case locations. is Door: refused (see below).
Interacts with	The move validates the same set, so a suggestion is never refused for its type (DestinationNotAuthorizedForSourceType).
When empty	No condition = the six authorized types.
If you change it	Next suggestion only.

Refusals (when the policy loads, so the whole policy is refused):

• is with only unauthorized types: Putaway step restricts locations to [Door], and a putaway may not land in any of them. Authorized types are [Case, Pick, SpeedPick, Pnd, Sort, Other].
• is not that covers all six: Putaway step excludes locations [Case, Pick, SpeedPick, Pnd, Sort, Other], and a putaway may not land anywhere else. Authorized types are [Case, Pick, SpeedPick, Pnd, Sort, Other].
• A value that is not a type: Putaway step criterion 12 (Location/LocationType Include) names value 'Mezzanine', which does not exist: <detail>. The criterion is refused rather than ignored — ignoring it would widen the search past what the policy author wrote. The same shape is used for every property below. It is prefixed by step <num> of policy <id>: (mod.rs:869-874).
• At save: 'Mezzanine' is not a value a 'LocationType' criterion can match — every comparison the engine makes is exact and case-sensitive. 'LocationType' offers: 'None', 'Other', ... (putaway_step_criterion.rs:486-501).

3.4.2 Location status

Item	Value
UI label	Location status.
Column read	location.status.
Type and values	Ok, Hold, Damage.
Default	No condition. The fixed gate already requires Ok.
What it does	Narrow-only. Every candidate already has status Ok. So the only useful forms are is Ok (redundant) and is not Hold (vacuous).
Affects	candidates.rs:300-354 (resolve_gated).
Example	is Ok: accepted, adds no filter.
Interacts with	You cannot use it to reach a location on hold.
When empty	No condition.
If you change it	Next suggestion only.

Refusals (policy load): is with anything but only Ok: Putaway step criterion 7 (Location/LocationStatus Include) asks for [Hold], and a putaway may only ever land on a location whose LocationStatus is 'Ok' — the candidate query enforces that unconditionally, regardless of this criterion. Include 'Ok', or drop the criterion. is not Ok: ... excludes 'Ok', and a putaway may only ever land on a location whose LocationStatus is 'Ok' — the step can therefore match no location at all.

3.4.3 Location category

Item	Value
UI label	Location category.
Column read	location.loc_category.
Type and values	None, NoPalletization, Asrs, CantileverRack, CartonFlow, DenseStorage, DoubleDeepRack, DriveInRack, DriveThroughRack, HorizontalCarousel, Other, PalletFlowRack, PalletCarousel, PushBackRack, SelectiveShelving, ShelvingStorage, WorkCenter.
Default	No condition.
What it does	Keeps only (or drops) locations of these storage equipment types.
Affects	candidates.rs:467-469.
Example	Location category is ShelvingStorage for small parts.
Interacts with	Seed locations use SelectiveShelving.
When empty	No condition.
If you change it	Next suggestion only.

3.4.4 Processing type

Item	Value
UI label	Processing type.
Column read	location.loc_processing_type.
Type and values	None, Pallet, Case, Piece.
Default	No condition.
What it does	Keeps locations handled by pallet, case or piece.
Affects	candidates.rs:470-472.
Example	Processing type is Pallet.
Interacts with	Nothing else reads this location field except this condition and the location generator.
When empty	No condition.
If you change it	Next suggestion only.

3.4.5 Location flag

Item	Value
UI label	Location flag.
Column read	location.loc_flag.
Type and values	None, CycleCountActive, SanitationActive, MaintenanceActive, ReceivingHoldoff.
Default	No condition. The fixed gate requires None.
What it does	Narrow-only, same as the status. is None is redundant. Any other is is refused.
Affects	candidates.rs:464-466.
Example	is None: accepted, no effect.
Interacts with	A flagged location is never a candidate.
When empty	No condition.
If you change it	Next suggestion only.

Refusal text has the same shape as for the status: ... may only ever land on a location whose LocationFlag is 'None' ....

3.4.6 Location ABC

Item	Value
UI label	Location ABC.
Column read	location.abc (default B).
Type and values	A, B, C (enum abc_speed_type).
Default	No condition.
What it does	Keeps fast (A), medium (B) or slow (C) locations.
Affects	candidates.rs:473-475.
Example	Location ABC is A or B.
Interacts with	Pairs with SKU ABC to put fast items in fast locations.
When empty	No condition.
If you change it	Next suggestion only.

3.4.7 Mixed SKU (location flag)

Item	Value
UI label	Mixed SKU, in family Location. Do not confuse it with the step switch Mixed SKU (2.10).
Column read	location.mix_sku.
Type and values	true, false.
Default	No condition.
What it does	Keeps locations whose flag Mix SKU is on (true) or off (false).
Affects	candidates.rs:476-478.
Example	Mixed SKU is false: only single-SKU locations.
Interacts with	The landing rule enforces the flag anyway (03-location-settings.md). This condition just avoids wasting candidates.
When empty	No condition.
If you change it	Next suggestion only.

Difference: the location flag looks at the location's setting. The step switch looks at what is in the location now.

3.4.8 Mixed lot (location flag)

Same as 3.4.7 for location.mix_lot (UI label Mixed lot, code MixLot, candidates.rs:479-481).

3.4.9 Location attribute

Item	Value
UI label	Location attribute (also needs an attribute from Choose an attribute).
Column read	attribute_value.value_text of the location, for attribute definitions with entity_type = 'location', type Text, active.
Type and values	Free text values. The attribute code comes from Sidebar > Attributes definitions.
Default	No condition.
What it does	Keeps locations whose attribute value is (or is not) in the list.
Affects	candidates.rs:507-511, SQL EXISTS (location.rs:1860-1925).
Example	Location attribute HAZMAT is not FLAMMABLE.
Interacts with	A location with no value for the code: is removes it; is not keeps it. Only Text definitions are offered.
When empty	No condition.
If you change it	Next suggestion only.

3.5 Product and lot conditions

These are checked once per step, before any location is read (product.rs:343-370). The rule is any line fails = the step is skipped. The pallet is one unit.

How a missing value is read:

• The five SKU-column properties (SKU ABC, SKU group, SKU class, Putaway class, Rotation): an empty SKU field does not refuse. A blank field is treated as "no opinion", so the step is not skipped. A line whose SKU did not load also does not refuse.
• The two attribute properties (Lot attribute, SKU attribute): a missing value refuses. The step asked a question. "Nothing recorded" is the answer "no".

3.5.1 SKU ABC

Item	Value
UI label	SKU ABC (SKU form: ABC Class).
Column read	sku.abc (schema default B).
Type and values	A, B, C.
Default	No condition.
What it does	The step applies only to pallets whose SKUs have these classes.
Affects	product.rs:344-346. Trace skipped:product:SkuAbc.
Example	Step 10 SKU ABC is A to zone FAST. A pallet with SKU class C skips step 10.
Interacts with	sku.abc is NULL for no SKU created by default (the default is B).
When empty	No condition.
If you change it	Next suggestion only.

3.5.2 SKU group

Item	Value
UI label	SKU group (SKU form: SKU Group).
Column read	sku.sku_group (text, up to 10).
Type and values	Free text. Case-sensitive. The picker offers the distinct groups now used by SKUs.
Default	No condition.
What it does	The step applies only to SKUs of these groups.
Affects	product.rs:347-349.
Example	SKU group is FROZEN. A SKU with group frozen does not match (case-sensitive).
Interacts with	A group no SKU uses yet is accepted.
When empty	A SKU with no group does not refuse.
If you change it	Next suggestion only.

3.5.3 SKU class

Item	Value
UI label	SKU class (SKU form: Class).
Column read	sku.class (text, up to 20).
Type and values	Free text, case-sensitive.
Default	No condition.
What it does	Same as SKU group, for the Class field.
Affects	product.rs:350-352.
Example	SKU class is HAZ.
Interacts with	None.
When empty	A SKU with no class does not refuse.
If you change it	Next suggestion only.

3.5.4 Putaway class

Item	Value
UI label	Putaway class (SKU form: Putaway Class).
Column read	sku.putaway_class (default None).
Type and values	None, NoMix.
Default	No condition.
What it does	The step applies only to SKUs with this class.
Affects	product.rs:353-355.
Example	Putaway class is NoMix with Mixed SKU = Not allowed sends no-mix SKUs to single-SKU locations.
Interacts with	NoMix on the SKU does nothing by itself. No code stops mixing because of it. A Putaway class condition (or a move rule, which is deferred: movement/validation.rs:8) is the only reader. Add the condition and the mixing switch yourself.
When empty	A SKU with an empty class does not refuse.
If you change it	Next suggestion only.

3.5.5 Rotation

Item	Value
UI label	Rotation.
Column read	sku.rotation (default Fifo).
Type and values	Fifo, Lifo, Fefo.
Default	No condition.
What it does	The step applies only to SKUs with this rotation.
Affects	product.rs:356-358.
Example	Rotation is Fefo to send expiry-driven goods to a front-loaded zone.
Interacts with	Rotation also drives allocation. Putaway only reads it in this condition.
When empty	No condition.
If you change it	Next suggestion only.

3.5.5a Pallet fullness

Item	Value
UI label	Pallet fullness.
Column read	None — computed for each pallet: its quantity against the base quantity of the top level of its pack hierarchy (the same "full pallet" allocation uses).
Type and values	Full — at least a full pallet (more than a full pallet is also Full); Partial — less, or several SKUs on the pallet.
Default	No condition.
What it does	The step applies only to pallets of this fullness.
When it cannot be measured	The pack has no level above its base unit: the step is skipped (skipped:product:PalletFullness), as for a lot attribute with no value.
Example	Pallet fullness is Partial on an AssignedSlot step: part pallets go straight to the pick location.
If you change it	Next suggestion only.

3.5.6 Lot attribute

Item	Value
UI label	Lot attribute (family Lot). Needs an attribute from Choose an attribute.
Column read	lot_attributes.attribute_value for (lot, attribute code). The codes offered are from the lot policies (lot_policy_attribute.attrib_code).
Type and values	Free text, case-sensitive. The picker offers values recorded on lots now.
Default	No condition.
What it does	The step applies only to pallets whose lots have these attribute values.
Affects	product.rs:359-363 and :442-457.
Example	Lot attribute ALLERGEN is YES. A pallet whose lot has no ALLERGEN value skips the step.
Interacts with	A lot is found by lot code alone (not by owner). A lot with no recorded value refuses. One condition per code.
When empty	No condition.
If you change it	Next suggestion only.

3.5.7 SKU attribute

Item	Value
UI label	SKU attribute. Needs a code.
Column read	attribute_value.value_text for the SKU, definitions with entity_type = 'sku' (Text, active). Defined under Sidebar > Attributes.
Type and values	Free text.
Default	No condition.
What it does	The step applies only to SKUs whose attribute has these values.
Affects	product.rs:364-368 and :477-495.
Example	SKU attribute COLOR is RED or BLUE.
Interacts with	The lot attribute COLOR and the SKU attribute COLOR are two different things. A SKU with no value refuses.
When empty	No condition.
If you change it	Next suggestion only.

---

4. Messages you can see

4.1 Policy and pallet errors (the whole request fails)

These are returned when the system cannot ask the question. They are not "no location".

Message	Meaning and fix
container N not found	The pallet id is wrong.
container N holds no stock to put away	Empty pallet.
container N has no current location to put away from	The pallet has no position. Move it to a location first.
no putaway policy on the SKU or the owner default	Set Putaway Policy on the SKU or the owner (1.5).
LPN spans SKUs with different putaway policies: SKU-A (owner 1, policy 10), SKU-B (owner 1, policy 20)	Split the pallet or use one policy. A SKU with no policy is not counted.
step uses scope=AssignedSlot, which this build cannot execute	Change the scope (2.2).
step uses ordering=NearestToSlot, which this build cannot execute	Change the ordering (2.7).
step sets allow_mixed_lot=... with allow_mixed_sku=...	See 2.11.
step sets require_empty=true together with allow_mixed_sku=... / allow_mixed_lot=...	See 2.9.
step sets mode=Consolidate together with require_empty=true ...	See 2.9.
step <num> of policy <id>: <message>	A condition names a value that does not exist (3.4.1).
suggest_location requires an open transaction ...	Programming error. Report to support.

Sources: policy.rs:19-41, step.rs:18-117, mod.rs:119-158.

4.2 Why a location is refused (rejection codes)

In the dry run and the trace, a step shows Refused by: <code> on <count>, .... The code is the engine's own text. These are all the codes.

Code	Check	Meaning	Exact detail text (if any)
excluded	request	You excluded this location (the operator refused it).
mix_intent	occupancy	Must be empty and the location is not empty or has another pallet's reservation.	step requires an empty location; occupied=true, inbound_reservations=1
mix_intent_sku	occupancy	Location plus pallet would hold more than one SKU.	step allows no mixing beyond the same sku; location plus pallet would span 2 identities: owner 1/sku A, owner 1/sku B
mix_intent_sku_lot	occupancy	More than one SKU+lot.	step allows no mixing beyond the same sku and lot; location plus pallet would span 2 identities: ...
not_consolidatable	mode	Consolidate and the location holds none of the pallet's products.	location holds nothing (no stock, no inbound reservation) — a Consolidate step requires the sku to already be there or step requires the location to already hold one of the pallet's (owner, sku) identities; location is committed to 1 other product(s): owner 1/sku B
capacity	fit	A limit is exceeded.	loc_cube: limit L, attempted A, loc_weight: ..., loc_qty: ..., loc_positions: ..., item_positions: ..., zone_cube: ..., zone_weight: ..., zone_cases_count: ..., loc_footprint: location 1200 × 800, pallet 1300 × 1100 (checked both orientations), loc_height: location 1500, pallet 1800
section_none	fit	Oversize goods and the location has no Section.	needs 3 adjacent positions of one free section
section_not_free	fit	Section too small or not wholly free.	same
section_too_small	fit	Section free but too small for the goods.	same
section_promised	fit	The location is held for another pallet's oversize goods.	held for goods spanning this section
location_not_found	fit	The location row vanished.	location X not found
zone_not_found	fit	The zone row is missing.	zone X not found
mix_sku	landing	The location has Mix SKU off and another SKU is there.	Location L does not allow SKU mixing (incoming sku B, existing ["A"])
mix_lot	landing	The location has Mix Lot off and another lot is there.	Location L does not allow lot mixing (incoming lot Some("L2"), existing ["L1"])
mix_attribute	landing	A location or zone Lot Commingle rule refuses.	attribute ALLERGEN=YES mixing not allowed for lot L2 on lpn Some("LPN1") [Some("putawayzone_lot_commingle rule on zone FOOD")]
lpn_multi_lot	landing	The pallet itself carries two lots of a SKU that does not allow that. Same answer at every location.	LPN1 already holds lot L1 of A; another lot of the same SKU is not allowed on it
ambiguous_sku	landing	A SKU could not be resolved.	ambiguous SKU resolution (...)
landing_config	landing	Bad data (location or SKU/owner missing).
landing_no_contents	landing	Empty pallet.	LPN X has no contents to put away
under_lock:<kind>	race	The location passed, then failed when locked (another operator won). <kind> is one of the codes above.
location_gone	race	The location changed or was deleted meanwhile.
lock_timeout	race	Another transaction held the location for more than 5 seconds (see 4.5).
pallet_already_reserved	race	Another request holds this pallet's reservation. The scan stops.

Codes that stop the whole request (database or system trouble, not a property of the location): landing_occupancy, section_lookup, mix_intent_system, consolidate_system, capacity_system, landing_system. The message is <code> while evaluating <location> for step <num> of policy <id>: <detail>.

Rare codes that the putaway path cannot reach today: lpn_owner_conflict, lpn_mix_sku.

Sources: predicate.rs:285-1017, mod.rs:657-778, wms-inventory/src/inventory_service.rs:999-1280, wms-inventory/src/error/commingle.rs.

4.3 Step status in the trace

Status	Meaning
skipped:guard	The guard did not match where the pallet stands.
skipped:product:<Property>	A pallet condition failed (the property is named).
skipped:no-zone	The scope found no zone (Zone from the SKU and the SKU has none).
skipped:no-location	The scope found no location.
skipped:temperature	The zone does not suit the pallet's temperature.
evaluated	The step searched and took nothing.
matched	The step took a location.

"Offered without checking": when a switch is on but the limit or the measure is missing the trace counts <limit>:<reason>. Limits: loc_cube, loc_weight, loc_qty, loc_footprint, loc_height, loc_positions, zone_cube, zone_weight, zone_cases_count. Reasons: no_limit (set up the location or zone), no_product_dims (item or pack master data), no_location_dims (location length/width/height), no_stock_weight (item weight).

The dry run sentence for a step that took nothing reads: step 02 (20) ran over 12 candidate(s) and took none of them. Refused by: capacity on 7, mix_sku on 5. Offered without checking: loc_cube:no_limit on 5 — the limit or the measurement is missing. It stopped at its scan budget rather than at the end of the zone, so there may be locations it never looked at.

4.4 Messages when you save a step or a condition

Step save (shown as cannot save — <reasons>):

• zone not chosen, location not chosen, source zone not chosen, source location not chosen
• one lot per location needs one SKU per location
• a location that must be empty has no mixing rules
• consolidating needs a location that already holds the stock, never an empty one

Database wording (API callers):

• Putaway step (policy P, sequence S) has scope 'X' but no to_zone — that scope needs its parameter
• Putaway step (policy P, sequence S) has guard 'X' but no from_zone — that guard needs its parameter
• Duplicate putaway step sequence (policy P sequence S) — steps of one policy need explicit, unique sequence values ...

Condition save:

• A 'LocationType' criterion narrows a column of its own, so it takes no attribute_code — but this one still carries 'COLOR', left over from an attribute property. Clear attribute_code, or pick the attribute property you meant.
• A 'SkuAttribute' criterion must name WHICH attribute it narrows on; attribute_code is empty.
• A 'LocationType' criterion with no values narrows the candidates to nothing, which reads in a trace exactly like an exhausted zone. Pick at least one value.
• This criterion's values were picked for LocationType and the change moves it to LocationStatus, without saying what the new values are. ... Send the values for LocationStatus as well.
• 'Mezzanine' is not a value a 'LocationType' criterion can match — every comparison the engine makes is exact and case-sensitive. 'LocationType' offers: ...

Whole save (all steps at once):

• putaway step 1012: condition 55 does not belong to this step
• putaway step 1012: SkuAttribute 'COLOR' carries more than one condition in this set — a step may narrow each property once
• putaway policy 5: step(s) 1013 do not belong to this policy
• Version conflict (code 40): someone saved first. The answer carries the current version. Reload and decide again. The whole save is refused if any step is stale.

Picker (putaway_criterion_vocabulary):

• an attribute_code was sent without a property — the property is chosen first, and which attributes exist depends on it
• a 'LocationType' criterion narrows a column of its own, so it takes no attribute_code — this request still carries 'COLOR'. Clear it, or pick the attribute property you meant.
• 'LotPolicy' is not a criterion property the putaway engine knows. It offers: LocationType, LocationStatus, ...

4.5 Settings that tune the engine (system level)

Setting	Where	Default	Effect
PUTAWAY_RESERVATION_TTL_MIN	Sidebar > System Settings (system_settings)	15 (seed BASELINE:9955); code fallback 15 (reserve.rs:22)	Minutes a suggested location is held. After that a sweeper (every 5 minutes) frees it.
Putaway Reservation TTL (min)	Owner, WH Settings (owner_config.putaway_reservation_ttl_min)	blank = use the warehouse value	Overrides the system setting for that owner. Must be above 0.
PUTAWAY_LOCK_TIMEOUT_MS	system_settings	Seeded 5000 (wms-app 091). Code default 5000 ms (DEFAULT_LOCK_TIMEOUT_MS)	How long one reservation waits for a busy location. A value of 0 or less is ignored (0 would mean "wait forever").
COUNT_ON_PUTAWAY_DEVIATION	system_settings (migration 071)	0	1 = when an operator accepts a deviation (code 85) from the suggestion, the destination location is queued for a count.

Reservation order: owner TTL, then PUTAWAY_RESERVATION_TTL_MIN, then its default, then 15 (reserve.rs:346-351, ttl_minutes).

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5. The "never runs" mark

A step is marked never runs when an earlier step already takes everything it could take. The mark reads closed by step N (S). The rule is on purpose cautious. It says "never runs" only when the settings prove it (wms-lib-core/src/model/policies/putaway_step_shadow.rs:130-168). The earlier step must, on every point, be at least as wide:

Point	Condition for "closed"
Guard	Earlier has no guard, or the same guard and anchor.
Pallet conditions	Each earlier pallet condition is implied by a later one (same property and attribute; is subset, is not superset).
Search space	Same scope, and the same zone/location for the two "named on this step" scopes.
Temperature	Later checks it whenever earlier does.
Ordering	Same value.
Location conditions	Equal sets (not subsets), because of the 100-candidate scan limit.
Mode	Not (Consolidate earlier and Suitable later).
Mixing	Later is at least as strict.
Fit checks	Later checks everything earlier checks.

Steps with AssignedSlot, NearestToSlot or a missing anchor are never marked.

6. The dry run

Panel Dry run (heading), field LPN / container, button Evaluate. Hint lines: evaluates the whole policy, not just this step and evaluates the SAVED policy — an edit is previewed only after Save. It runs the real engine on a real pallet and then rolls back (putaway/command.rs, explain_location). Nothing is reserved. Role: Admin, Manager, Supervisor.

Result columns: Candidate location, Rule, Outcome, Detail. Heading On this pallet lists the lines. Messages:

• Type an LPN to see what the engine would do with it.
• The engine would not evaluate this pallet: <reason>
• Nothing is on LPN X — the engine has no pallet to place.
• LPN X is loose stock rather than a container, and the putaway engine places containers — there is nothing here for it to put away.
• What is on LPN X resolves to policy 7, not policy 5 — a dry run over it would not exercise these steps. Try an LPN whose SKUs point at this policy.
• The engine reached no policy at all for LPN X, so there is nothing to compare policy 5's steps against.
• Winner: step 02 (20) wins — the engine would put this pallet into B-04-2. (the label is step <position> (<stored number>), dry_run.rs:918-924).
• No winner: No step offers a location: every candidate in every step was refused. or another request already holds this pallet's reservation, so the scan stopped early.
• Per step: step 01 (10) is not about this pallet: its SkuAbc condition does not hold for what is on it., step 01 (10) was skipped: its guard limits it to stock that came from somewhere else., ... was skipped: it resolved no zone to search., ... was skipped: it resolved no location to search., ... was skipped: its zone's temperature range does not suit every line on this pallet., step 03 (30) was not reached — an earlier step matched first.
• A reservation is not made. The error on a failed call: The dry run could not be made. Try again, or refresh the screen.