Allocation Policy: Header, Steps and Criteria

This page lists every setting of the allocation policy. Page 10 explains how the engine thinks. Read it first if you are new.

Paths start at crates/libs/ unless they say otherwise. file:line shows where to check a claim.

1. Where you work

What	Menu path or API	Roles
Policy list and header	Sidebar > Policy > Allocation Policy. Buttons: New, Delete, Refresh, Duplicate.	Admin, Manager, Supervisor (write). Everyone with the screen can read.
Step editor	Click a policy row. The step page opens (navigation nav_allocation_policy_row_opens_step_page).	same
Lifecycle buttons	Validate, Publish, Deactivate on the policy form toolbar	same
SKU link	Sidebar > SKU > open the SKU > tab Policies > Allocation Policy	SKU editors
Owner default	Sidebar > Owner > open an owner of type Own > tab WH Settings > inner tab Policies > Allocation Policy	Owner editors
Rotation facts	Sidebar > SKU > open the SKU > tab Shelf Life: Rotation, Rotate By, Min Shelf Life on Pick	SKU editors

API methods (all in app-server/src/web/rpcs/allocation_policy_rpc.rs):

Method	Kind	Idempotency key	Version in request	Line
create_allocation_policy	stateless command	yes	no	91
update_allocation_policy (header)	stateful command	yes	expected_version of the policy	179
delete_allocation_policy, delete_many_allocation_policy	stateless command	yes	no	109, 126
allocation_pipeline_view	query	no	no	238
allocation_steps_save	stateful command	yes	one expected_version per step	270
allocation_step_add	stateless command	yes	no	305
allocation_step_delete	stateful command	yes	expected_version of the step	331
allocation_steps_reorder	stateful command	yes	expected_policy_version	363
allocation_policy_validate	query	no	no	388
allocation_policy_publish	stateful command	yes	expected_version	402
allocation_policy_deactivate	stateful command	yes	expected_version	426
allocation_policy_clone	stateless command	yes	no	450
get_/list_/count_allocation_policy, get_/list_/count_allocation_policy_detail	reads	no	no	generated

Steps are read-only through the generic CRUD. All step writes go through the allocation_step* commands (allocation_policy_rpc.rs:208-211).

2. Life cycle of a policy

A policy is a draft until you publish it. After that it never changes. To change it, copy it.

State	active	published_at	retired_at	What you may do
Draft	false	empty	empty	Edit header and steps. Validate. Publish. Delete.
Published	true	set	empty	Use it. Duplicate it. Deactivate it. Nothing else.
Retired	false	set	set	Duplicate it. Nothing else. A retired policy cannot come back.

The database enforces the pairs (wms-lib-sql/sql/wms-app/migrations/028_allocation_policy_publication_lifecycle.sql:20-26):

• ck_allocation_policy_active_is_published: NOT active OR (published_at IS NOT NULL AND retired_at IS NULL). A policy can be active only when it is published and not retired.
• ck_allocation_policy_retired_was_published: retired_at IS NULL OR (published_at IS NOT NULL AND NOT active). A retired policy was published and is not active.

Rules in code (wms-outbound/src/domain/allocation_policy/aggregate.rs:38-82):

Action	Allowed when	Refusal text
Edit header, add/save/delete/reorder steps, delete policy	Draft	allocation policy '{code}' is published and immutable; clone it to create a new draft or ... is retired and immutable; clone it to create a new draft
Publish	Draft	allocation policy '{code}' is not a draft
Deactivate	Published and active	allocation policy '{code}' is not currently published

Publish runs the full validation first (section 6). If anything fails: allocation policy '{code}' cannot be published: {reason}; {reason} (wms-outbound/src/service/policy/lifecycle.rs:60-70). Publish adds 1 to version (allocation_policy.rs:248-268). Deactivate also adds 1 (:272-293).

Messages on the policy toolbar (web-ui-server/src/extensions/customization/allocation/policy_lifecycle_action.rs:37-53, :122, :136):

• Validate: Policy is valid and can be published or Policy is not publishable: {reasons joined by "; "} or Policy validation failed.
• Publish: Policy published.
• Deactivate: Policy deactivated.
• Duplicate: Duplicated {old code} as {new code} ({n} step(s)); errors Select a policy to duplicate, Select exactly one policy to duplicate, That policy no longer exists — refresh the list and try again (policy_duplicate_action.rs:77-118).

Duplicate (API allocation_policy_clone) makes a new draft. It copies the three header flags, the description and name, and every step with its rule_num, sequence and active (lifecycle.rs:118-190). The new code is the old code plus -C, then -C2, -C3 ... The old code is cut so that the result fits 10 characters (policy_duplicate_action.rs:36-45, up to 20 tries).

Warning (bug, to verify). Deactivate raises version, but an order line keeps the version it froze. The runtime then refuses the line: allocation policy '{code}' version mismatch for sku '{sku}': line froze version {a}, current version is {b} (wms-outbound/src/allocation/policy.rs:209-215, allocation_policy.rs:278-283). The code comment says "deactivation blocks new bindings only; it cannot rewrite execution of an existing order" (policy.rs:201-202), and the integration test proves that only with a raw UPDATE ... SET active = false that does not bump the version (tests/allocation_command_integration.rs:604-631). To verify on a test warehouse: create an order line with a published policy; press Deactivate on that policy; press Allocate on the order. If you read the "version mismatch" text, the bug is confirmed. Until it is fixed, do not deactivate a policy while open orders use it. Instead, publish a new policy and move the SKU or owner default to it.

3. Header settings (table allocation_policy)

Schema: wms-lib-sql/sql/wms-app/migrations/001_baseline.sql:1297-1312. Lifecycle columns: migration 028.

3.1 id

Item	Value
UI label	ID (hidden on an existing record by the code-read-only render binding)
Column	allocation_policy.id
Type	bigint, generated. The sequence starts at 1000 (001_baseline.sql:10124).
Default	seed row has id 1
What it does	Key. SKU, owner config and order lines point to it.
What it affects	sku.allocation_policy_id, owner_config.default_allocation_policy_id, shipment_order_line.allocation_policy_id (policy.rs:41-46)
When you change it	You cannot.

3.2 code

Item	Value
UI label	Code (list column and form field)
Column	allocation_policy.code
Type and range	text, 1 to 10 characters, unique (allocation_policy_code_key), spaces at both ends are cut. A blank code is refused: allocation policy code cannot be empty (allocation_policy.rs:213-218).
Default	none. Seed: STD.
What it does	The name people use. Shown in the SKU and owner pickers (popup value picker on code), in every policy error text and in Duplicate.
What it affects	Messages in allocation/policy.rs:122-145, :238-257.
Example	FEFO for a policy that takes the nearest expiry first.
Interactions	The code cannot be edited after the record exists. The form locks it and the API update_allocation_policy has no code field (allocation_policy_rpc.rs:149-157).
When empty	Not allowed.
When you change it	You cannot. Duplicate under a new code.

3.3 name

Item	Value
UI label	None. The field is not on any form.
API	create_allocation_policy (name), update_allocation_policy (name, three states: leave out = keep, null = clear, text = set) (allocation_policy_rpc.rs:34-43, :149-176).
Column	allocation_policy.name
Type and range	text up to 50 characters, may be empty (NULL)
Default	NULL
What it does	Stored only. It has no effect today. Duplicate copies it (lifecycle.rs:166). Nothing else reads it (checked with a search for policy.name in wms-outbound).
When you change it	Only on a draft.

3.4 descr

Item	Value
UI label	Description (list and form, required on the form)
Column	allocation_policy.descr
Type and range	text up to 255 characters
Default	empty text
What it does	A note for people. The list shows it. Allocation does not read it.
When you change it	Only on a draft.

3.5 strict_lot_rotation

Item	Value
UI label	None. API only (create_allocation_policy, update_allocation_policy).
Column	allocation_policy.strict_lot_rotation
Type	true or false
Default	false
What it does	Reserved for a future "never skip an older lot" rule. The engine does not run it. If it is true, Validate and Publish refuse the policy with header flag strict_lot_rotation=true is not executable by this build (code UNSUPPORTED_HEADER_FLAG) (wms-outbound/src/service/policy/validate.rs:44-57). Allocation itself never reads the flag.
What it affects	Only publication and Duplicate (it is copied).
When you change it	A policy that was already active before migration 028 and has the flag on is listed by the view allocation_policy_publication_preflight (migration 028) so that the owner can fix it. Runtime does not check the flag.
Advice	Leave it false.

3.6 allow_overallocation

Same as 3.5. Message: header flag allow_overallocation=true is not executable by this build. API only. Default false. Intended meaning: reserve more than exists. Not available.

3.7 speed_pick_by_uom

Same as 3.5. Message: header flag speed_pick_by_uom=true is not executable by this build. API only. Default false. Intended meaning: a fast-pick mode by unit of measure. Not available.

3.8 active

Item	Value
UI label	None. The state shows through Published at and Retired at. You change it with the buttons Publish and Deactivate.
Column	allocation_policy.active
Type	true or false
Default	false (since migration 028; before it was true). A new policy is always created as a draft, even if the caller sends active = true (allocation_policy.rs:186, :221).
What it does	true means published and in use.
What it affects	resolve_policy: a new order line cannot bind an inactive policy (allocation/policy.rs:129-135). Existing lines do not check the flag (policy.rs:203-236).
Interactions	See the check constraints in section 2. The API header update does not accept active.
When you change it	See the warning in section 2 about Deactivate.

3.9 published_at, retired_at

Item	Value
UI label	Published at, Retired at (list columns and read-only form fields)
Column	allocation_policy.published_at, allocation_policy.retired_at
Type	date and time with time zone, empty until the event
Default	empty. The seed STD got published_at = add_when from migration 028.
What it does	Mark the life-cycle events. Together they define Draft, Published, Retired (section 2).
When you change it	You cannot edit them. Publish sets published_at; Deactivate sets retired_at.

3.10 version

Item	Value
UI label	Version (read-only)
Column	allocation_policy.version
Type	integer, at least 1
Default	1
What it does	Optimistic lock. Every write must send the version it read. A stale write is refused with code 40 (version conflict on allocation_policy ...) and the answer carries the current version.
What it affects	The order line copies it when the line is created. At allocation time the policy version must still be equal (policy.rs:209-215).
When you change it	The system adds 1 on Publish, Deactivate, header save and reorder.

3.11 Audit columns

add_who, add_when, mod_who, mod_when: who and when created or changed the row. Filled by the system. No effect on allocation.

4. Step settings (table allocation_policy_detail)

A step is one rule row. Each row has its own version. Schema: 001_baseline.sql:1321-1346. Row identity: unique (allocation_policy_id, sequence) and unique (allocation_policy_id, rule_num) (001_baseline.sql:12625-12643). Deleting a policy deletes its steps (migration 016).

New step defaults. The button Add step creates a row with only column defaults (service/policy/add_step.rs:60-72): allocation_type = Firm, uom_code = EA, sort_1 = LotRotation, lpn_quantity_rule = Any, one_pick_per_uom_location = true, active = true, all other filters empty.

The seed step of STD: id 1000, rule_num = 1, sequence = 0, active, Firm, unit EA, no location filters, Any, no quantity fit, one pick per UOM location = true, sort_1 = LotRotation, sort_2 = Location (001_baseline.sql:7651-7653).

The editor has four bands: Source, Conditions, Selection, Output. Their hints are what this step reserves, and from where, which stock qualifies, in what order positions are taken, how what it reserves becomes task lines. The header of a step reads Step {n} · rule {rule_num}.

4.1 id, allocation_policy_id

Key and parent. The step belongs to one policy (foreign key, delete cascades). The editor never shows them. A save that names a step of another policy is refused: allocation policy {id}: step(s) {ids} do not belong to this policy (service/policy/save_steps.rs:236-246).

4.2 rule_num

Item	Value
UI label	Part of Step {0} · rule {1}; the crumb Step {0}; closed by step {0}
Column	allocation_policy_detail.rule_num
Type and range	text, up to 5 characters, unique in the policy
Default	The system numbers it. It uses the spelling of the new sequence: 10, 20, ... If that is taken, it counts up (wms-lib-core/src/model/policies/step_numbering.rs:78-100). Seed: 1.
What it does	The label people read. It never decides order. Order comes from sequence.
What it affects	The text closed by step {rule_num} and the validation text step '{rule_num}' ...; the pick keeps the step id and step version, not the number.
When you change it	You cannot. A save that carries rule_num is refused: Allocation step {id}: a step's number is assigned when the step is added and never changes ... (allocation_policy.rs:871-876).

4.3 sequence

Item	Value
UI label	The position of the card in the list. You drag cards to change it.
Column	allocation_policy_detail.sequence
Type and range	whole number, unique in the policy (negative numbers are used only while reordering)
Default	column default 0. A new step takes the highest sequence + 10 (first step: 10) (allocation_policy.rs:636, step_numbering.rs:78-90).
What it does	Execution order. Step with the lowest number runs first. Ties are broken by id (allocation_policy.rs:1023-1040).
What it affects	trace.rs:534 (the loop over steps), the "closed by" rule
Example	Steps 10 (PL), 20 (CS), 30 (EA) run in that order.
Interactions	Order matters for the carry: what step 10 cannot cover goes to step 20, whatever its unit.
When you change it	Only through the reorder command, which checks the policy version (allocation_steps_reorder). A save that carries sequence is refused: Allocation step {id}: a step's place in the pipeline moves only through the reorder command ... (allocation_policy.rs:891-897).

4.4 active (step)

Item	Value
UI label	None. The card shows the badge not active and the text switched off — the engine does not run this step. There is no switch on the card today.
API	allocation_steps_save with "active": false in fields.
Column	allocation_policy_detail.active
Type	true or false
Default	true
What it does	false means the engine never loads the step. It is as if the row did not exist (allocation_policy.rs:1033).
What it affects	resolve_policy, load_frozen_policy (policy.rs:137, :216). If all steps are off: allocation policy '{code}' has no active steps ....
Interactions	Off steps do not count in validation, nor in the "closed by" check. They do count when a new step gets its number.
When you change it	Only on a draft.

4.5 version (step)

Optimistic lock of the step. Every save sends expected_version per step. If any step has moved, nothing is saved and the answer lists all moved steps (save_steps.rs:130-176). Delete also needs the version. The system adds 1 on each save.

4.6 allocation_type (band Source)

Item	Value
UI label	Allocation type
Column	allocation_policy_detail.allocation_type (enum allocation_type)
Values	Firm, Soft, SoftCartonization (table below)
Default	Firm
What it does	How firmly stock is committed. Only Firm runs.
What it affects	allocation/step.rs:202-212. Any other value makes the whole policy unusable (section 6).
Example	A step with Soft: publish is refused with step '20': step uses allocation_type=Soft, which this build cannot execute.
When empty	Not possible (not null).

Value	Picker text	Meaning in this build
Firm	Firm — reserves	Reserves the stock now. This is the only value that runs.
Soft	Soft + note not implemented yet	Would let stock be taken away by a more important order. Refused.
SoftCartonization	Soft + cartonization + note not implemented yet	Would wait for a carton plan. Refused.

4.7 uom_code (band Source)

Item	Value
UI label	Unit of measure (picker title Choose a unit, search search code or name…)
Column	allocation_policy_detail.uom_code
Type and range	text, up to 10 characters, must not be blank. The picker offers the active values of the code list UOM.
Default	EA
What it does	The unit the step reserves in. The engine splits the line need over the pack rungs. A step gets the share of its own unit (plus the carry).
What it affects	trace.rs:331 (units named by steps), trace.rs:535 (the share), trace.rs:853-878 (splitting of picks). Also resolve_policy_for_new_line (policy.rs:185-194).
Example	Pack PL=1000, CS=100, EA=1. Need 2340. Steps with units PL, CS, EA get 2000, 300 and 40.
Interactions	A rung that no active step names is not used (not even for splitting). Two steps with the same unit: the first takes the share, the second gets only the carry. If the pack does not carry the unit, the step gets only the carry (verdict NoQuantityForUom when the carry is also zero). The picker marks measured units.
When empty	A blank unit is refused at publish: step '{rule}' has an empty UOM (code EMPTY_UOM).
When you change it	Only on a draft. Orders already placed keep the old policy.

4.8 location_type (band Source)

Item	Value
UI label	Location type
Column	allocation_policy_detail.location_type (enum loc_type, may be NULL)
Values	See the table below.
Default	NULL = "Any"
What it does	The step looks only at locations of this type.
What it affects	inventory_balance_atp.rs:462 (l.loc_type = value).
Example	Step 10 Pick and step 20 empty: pick faces are emptied first.
Interactions	The value None is a real location type (the text "None"), not "any". Choose the empty option for "any". InTransit and Pack locations are never used, even with an empty field (inventory_balance_atp.rs:343).
When empty	Any location type except InTransit and Pack. See the warning in page 10, section 5.
When you change it	Draft only.

Value	Allowed in a step?
None, Other, Case, Pick, Pnd, Door, Pickto, Sort, SpeedPick	Yes. The engine compares the text with location.loc_type. Their meaning is set by your location master data.
QC, Damage, Rtv, Destroy, Returns, Stage, Lost	No. Picker note: not an allocation candidate — a hold-stage zone purpose. Text on the card: location type {value} is a hold-stage zone, never allocated from.
InTransit	No. Picker note: not an allocation candidate — the location of open pick pallets.
Pack	No. Picker note: not an allocation candidate — a pack station.

4.9 putawayzone (band Source)

Item	Value
UI label	Putaway zone
Column	allocation_policy_detail.putawayzone (text up to 20, foreign key to putawayzone.code, may be NULL)
Default	NULL = "Any"
What it does	The step looks only at locations whose putawayzone equals this code.
What it affects	inventory_balance_atp.rs:459
Example	Zone FAST for a fast-pick area.
Interactions	A zone that is still used by a step cannot be deleted (restrict).
When empty	All zones.
When you change it	Draft only.

4.10 location_category (band Conditions)

Item	Value
UI label	Location category
Column	allocation_policy_detail.location_category (enum loc_category, may be NULL)
Values	None, NoPalletization, Asrs, CantileverRack, CartonFlow, DenseStorage, DoubleDeepRack, DriveInRack, DriveThroughRack, HorizontalCarousel, Other, PalletFlowRack, PalletCarousel, PushBackRack, SelectiveShelving, ShelvingStorage, WorkCenter (17 values; wms-lib-core/src/model/location.rs:300-318)
Default	NULL = "Any"
What it does	Only locations of this category. The value None is a real category, not "any".
What it affects	inventory_balance_atp.rs:460
Example	SelectiveShelving to take from shelves only.
When empty	All categories.
Counted in the band	The band header shows {n} of 3 conditions set or no conditions set (Conditions.tsx:35-45).

4.11 location_abc (band Conditions)

Item	Value
UI label	Location ABC
Column	allocation_policy_detail.location_abc (enum abc_speed_type: A, B, C; may be NULL)
Default	NULL = "Any"
What it does	Only locations of this velocity class.
What it affects	inventory_balance_atp.rs:461
Example	Step 10 A, step 20 empty: the fast movers' locations are used first.
When empty	All classes.

4.12 lpn_quantity_rule (band Conditions)

Item	Value
UI label	LPN quantity
Column	allocation_policy_detail.lpn_quantity_rule (enum lpn_qty_rule)
Values	Any, EqPackPallet, NePackPallet
Default	Any
What it does	Filters the candidate rows by comparing each row's available quantity with the pallet quantity of the pack. The pallet quantity is the biggest rung of the pack above the base unit (trace.rs:466-469).
What it affects	allocation/select.rs:258-275
Interactions	Runs before Quantity fit (intersection). An EqPackPallet step is never split into smaller picks, whatever One pick per UOM / location says (trace.rs:858-862).
When you change it	Draft only.

Value	Picker text	Behaviour	Example (pallet = 1000; rows: LPN 1000, LPN 999, LPN 1001, LPN 500, loose 1000)
Any	Any allocatable stock	No filter.	All five rows.
EqPackPallet	Only positions on an LPN whose available quantity is exactly one full pallet	Keep a row only when its available quantity equals the pallet quantity and it has an LPN. If the pack has no pallet rung, nothing qualifies.	Only LPN 1000. Loose 1000 is not kept.
NePackPallet	Except positions whose available quantity is exactly one full pallet	Drop rows whose available quantity equals the pallet quantity. Rows with more than a pallet stay. If the pack has no pallet rung, it works as Any.	LPN 999, LPN 1001, LPN 500. Loose 1000 is dropped too (its quantity equals the pallet).

A full-pallet step may still take only part of a pallet: if the need is 250, it takes 250 from the 1000-pallet (select.rs:207). The rule filters the source, not the amount.

Measured units (weighed or cut) make EqPackPallet useless; the card warns: {uom} is measured, so no LPN ever holds a full pallet of it — the full-pallet rule can never be met (never reserves).

4.13 qty_fit_rule (band Selection)

Item	Value
UI label	Quantity fit
Column	allocation_policy_detail.qty_fit_rule (enum qty_fit, may be NULL)
Values	LowToHigh, ExactFit, BiggerFit, BestFit, HighToLow
Default	NULL = no rule
What it does	Compares the available quantity of each position with the need of this step (need_uom). Filter and/or order. The need is fixed at the start of the step.
What it affects	select.rs:296-316 (filter), select.rs:381-395 (order)
Interactions	Needs LpnQuantity in at least one sort rank. If not, the step is refused: step names qty_fit_rule={rule} but no sort_1..sort_4 names LpnQuantity — ... (step.rs:132-138). Runs after LPN quantity.
When empty	No quantity filter. If LpnQuantity is ranked, it sorts by available quantity, smallest first.
When you change it	Draft only.

Example for all values. Need of the step = 250. Positions (available): 100, 250, 300, 800. LpnQuantity is rank 1.

Value	Picker text	Positions kept	Order	Result
LowToHigh	Low to high — smallest available quantity first	all	smallest first	100, then 150 from the 250 position
ExactFit	Exact fit — only positions holding exactly that quantity count	only 250	n/a	250 from the 250 position. If no position holds exactly the need, the step finds nothing and the full need goes to the next step.
BiggerFit	Bigger fit — only positions holding at least that quantity count	250, 300, 800	smallest first	250 from the 250 position
BestFit	Best fit — only positions holding at most that quantity count	100, 250	largest first	250 from the 250 position
HighToLow	High to low — largest available quantity first	all	largest first	250 from the 800 position

BestFit and ExactFit can leave part of the need open. ExactFit with a measured unit "will nearly always reserve nothing" (card text).

4.14 one_pick_per_uom_location (band Output)

Item	Value
UI label	One pick per UOM / location. The toggle text is merged into one task line per location (on) or a task line per LPN (off).
Column	allocation_policy_detail.one_pick_per_uom_location
Type	true or false
Default	true (schema, seed and Add step)
What it does	On (true): no change. One pick per stock position (one balance row: lot, location, LPN). Off (false): each draw is cut into pieces of one unit of the step's unit. A draw of 400 EA-base units in unit CS (100) becomes 4 picks of 100. The last piece may be smaller.
What it affects	trace.rs:853-878 (explode_step_draws); one task is created per pick (picking/infrastructure/tasks.rs:52-83).
Example	Step unit CS, draw 400 from one location. On: 1 pick of 400. Off: 4 picks of 100, 4 tasks.
Interactions	No cut for EqPackPallet steps. No cut when the unit is not on the pack ladder, or its base_qty is zero or dust (0.000001 or less) (trace.rs:858-862). A base unit step (EA) with Off makes one pick per each: 3456 EA = 3456 picks; there is no cap (trace.rs:846-852).
When empty	Not possible (not null).
When you change it	Draft only.

Text problem (inconsistency). The words on the toggle say "merged into one task line per location". The code does not merge picks of different lots or LPNs. On means "one pick per position". The label is misleading when a location holds several lots or LPNs. See trace.rs:763-833, which says that true has "nothing to merge".

4.15 sort_1, sort_2, sort_3, sort_4 (band Selection)

Item	Value
UI label	Sort ranks (picker title Choose a sort rank). The card shows ranks 01..04; the next free rank is shown as an empty slot.
Columns	sort_1 (required), sort_2, sort_3, sort_4 (may be NULL). Enum alloc_sort.
Values	LotRotation, Location, LpnQuantity (run). Lpn, LpnRotationInLoc, LocationAbc (refused).
Default	sort_1 = LotRotation, others NULL. Seed: sort_2 = Location.
What it does	The ranks are a ladder. Rank 1 is the main key. Rank 2 only breaks ties of rank 1. And so on.
What it affects	select.rs:181-196
Example	LotRotation, then Location: oldest lot first. Inside one lot, lower route_sequence first.
Interactions	Clearing rank 2 moves rank 3 up; the editor rewrites all four columns (Selection.tsx). Quantity fit needs LpnQuantity in one rank.
When empty	sort_1 cannot be empty. Ranks 2 to 4 may be. If every key ties, the order follows the read order (balance id).
When you change it	Draft only.

Value	Picker text	Behaviour	Runs?
LotRotation	Lot rotation — the SKU's rotation	Follows sku.rotation and sku.rotate_by (section 7). An empty date sorts last.	Yes (select.rs:323-363)
Location	Location — route order	location.route_sequence as text, then location.code. Text order: 10 before 2.	Yes (select.rs:365-372)
LpnQuantity	LPN quantity — available quantity	Available quantity, smallest first; largest first if Quantity fit is BestFit or HighToLow.	Yes (select.rs:381-395)
Lpn	LPN + not implemented yet	Refused.	No
LpnRotationInLoc	LPN rotation within location + not implemented yet	Refused.	No
LocationAbc	Location ABC speed + not implemented yet	Refused.	No

A refused sort gives: step uses sort_{n}={value}, which this build cannot execute (step.rs:74-75, :178-188).

4.16 Audit columns of a step

add_who, add_when, mod_who, mod_when. No effect on allocation.

5. Meaning of the other values used above

Enum	Values	Source
SKU Rotation (sku_rotation)	Fifo: oldest first. Lifo: newest first. Fefo: earliest expiration first, always by expiration date.	select.rs:323-363, wms-lib-core/src/model/sku.rs:128-132
SKU Rotate By (code list ROTATEBY)	Lot (lot number; sorts by the creation time of the lot row, not the code), Mandate (manufactured date), ExpDate (expiration date), BestBy (best by date), DelivBy (delivery by date)	select.rs:40-60, baseline 7819-7822, 8065-8066
Policy state	Draft, Published, Retired	section 2
Step verdict in the preview	selected (took stock), no_candidates (the read found nothing), no_quantity_for_uom (step had no share and no carry), filtered_by_fit (positions existed but the LPN rule or quantity fit removed them all)	trace.rs:90-97, :614-619
Rejection counters (preview with detail = full)	held, location_not_allocatable, shelf_life_failed, pack_mismatch, step_location_filter_failed, lpn_rule_failed, fit_failed. The first five are exclusive: a row is counted in the first bucket it fails.	trace.rs:103-125, inventory_balance_atp.rs:350-409

6. Validation and what the step card says

Validate and Publish use the same parser that allocation uses at run time, so they cannot disagree (validate.rs:38-100). Issue codes:

Code	Text	When
UNSUPPORTED_HEADER_FLAG	header flag {flag}=true is not executable by this build	One of the three header flags is on
NO_ACTIVE_STEPS	policy must have at least one active step	No active step
EMPTY_UOM	step '{rule_num}' has an empty UOM	A blank unit
UNSUPPORTED_STEP	step '{rule_num}': {reason} where the reason is step uses allocation_type={v}, which this build cannot execute, or step uses sort_{n}={v}, ..., or step uses location_type={v}, ..., or the qty_fit_rule text from 4.13	Any value that the engine refuses
SHADOWED_STEP	step id {id} is unreachable because step '{rule_num}' consumes its candidate set first	See below

Closed steps ("closed by step N"). A later step is closed when an earlier active step with the same uom_code takes every position the later one could take. The rule is cautious. It says "closed" only when all of these hold (wms-lib-core/src/model/policies/allocation_step_shadow.rs:99-120):

• same policy, earlier sequence, earlier step is active and runnable;
• same unit;
• the earlier step has LPN quantity = Any and Quantity fit empty, LowToHigh or HighToLow (these do not remove positions);
• for zone, location type, category and ABC: the earlier step has no filter on that axis, or the same filter value as the later step.

Example: step 10 EA, no filters; step 20 EA, zone FAST. Step 20 is closed by step 10, because step 10 already takes the zone FAST positions. Publish refuses this. Put the narrow step first instead.

Marks on the card (narration texts, wms-lib-core/src/model/narration/mod.rs:2071-2093):

Mark	Meaning
never runs + The engine skips this step when it loads the policy, so it reserves nothing: ...	The step uses a refused value. Because the whole policy is refused at run time, the order gets the error in section 4 of page 10.
never reserves	The step runs but cannot match anything (a measured unit with EqPackPallet or ExactFit).
not active	The step is switched off.
closed by step {rule}	See above.
Line under the last step	whatever is still unreserved is a shortfall on the line and goes to backorder (see page 10, section 6: there is no backorder object)
No steps yet. A policy with an empty pipeline reserves nothing.	No steps.
unsaved changes, The steps are saved.	Draft state of the editor

The step editor reads one query (allocation_pipeline_view) and shows the sentence for each step, so you can read what the engine will do. A step that the engine refuses gets only the "never runs" sentence.

7. Settings outside the policy that the engine reads

7.1 sku.allocation_policy_id

Item	Value
UI label	Allocation Policy (SKU, tab Policies)
Column	sku.allocation_policy_id
Type	policy id, may be NULL. Foreign key, restrict on delete.
Default	NULL
What it does	The policy for this SKU. First choice.
What it affects	SkuBmc::resolve_allocation_policy (wms-lib-core/src/model/sku.rs:950-968), used when a line is created or saved (service/order/create.rs:177, service/order_line/upsert.rs:108).
Interactions	Wins over the owner default (COALESCE(sku, owner)).
When empty	The owner default is used. If that is empty too: sku '{sku}' (owner {owner}) has no allocation policy ....
When you change it	Only new lines and lines saved again through the line editor use it. Lines already created keep their frozen policy (test: tests/allocation_command_integration.rs:565-600). A line can be saved again only while it is in the New family and has no reservation.

7.2 owner_config.default_allocation_policy_id

Item	Value
UI label	Allocation Policy (Owner, tab WH Settings, inner tab Policies; shown only for owner type Own)
Column	owner_config.default_allocation_policy_id
Type	policy id, may be NULL. Foreign key, ON DELETE SET NULL (001_baseline.sql:17181-17185).
Default	NULL in the schema. The seed sets 1 (STD) for owners 1 and 2 (001_baseline.sql:8538-8539).
What it does	The policy for every SKU of the owner that has none.
When empty	See 7.1.
When you change it	As 7.1. Note: deleting a draft policy that an owner uses sets this field to NULL without a message.

7.3 sku.rotation

Item	Value
UI label	Rotation (SKU, tab Shelf Life)
Column	sku.rotation (enum sku_rotation, not null)
Values	Fifo, Lifo, Fefo
Default	Fifo
What it does	Direction of the sort rank LotRotation.
What it affects	trace.rs:916, select.rs:323-363
Interactions	Fefo ignores Rotate By and always uses the expiration date. Used only if a step has the rank LotRotation.
Example	Page 10, example 9.1.

7.4 sku.rotate_by

Item	Value
UI label	Rotate By (SKU, tab Shelf Life)
Column	sku.rotate_by (text up to 20, not null)
Values	Lot, Mandate, ExpDate, BestBy, DelivBy
Default	Lot
What it does	Which date Fifo and Lifo sort by.
What it affects	trace.rs:917-928
When empty or wrong	A value outside the list stops allocation with sku '{sku}' has rotate_by = '{value}', not a value the ROTATEBY code list defines (Lot/Mandate/ExpDate/BestBy/DelivBy).

7.5 sku.min_shelf_life_on_pick

Item	Value
UI label	Min Shelf Life on Pick (SKU, tab Shelf Life)
Column	sku.min_shelf_life_on_pick (integer days, may be NULL)
Default	0
What it does	A lot is a candidate only if its expiration date is LATER than today + max(value, shelf_life, 0) days, or it has no expiration date and none is required (the lot policy asks for one, or the SKU has expire_days above zero). Today is the warehouse day (WAREHOUSE_TIMEZONE; UTC when blank).
What it affects	find_allocation_candidates and trace.rs (lot_dating::threshold). The pick commit judges the same boundary with value alone and refuses SOURCE_EXPIRED (judge_pick_lot, picking/confirmation/shelf_life.rs).
Example	Value 30 on 10 Oct 2026: lots that expire on 9 Nov 2026 or earlier are skipped; 10 Nov passes.
When empty	Same as 0: lots that expire today or earlier are skipped.
Also read	shelf_life (minimum days at shipping, the larger of the two applies) and expire_days (with the lot policy, whether an expiration is required). min_shelf_life_on_rec is not read by allocation; it is a receiving check.

7.6 shipment_order_line.allocation_policy_id and allocation_policy_version

Item	Value
UI label	None. API fields of the line.
Columns	both on shipment_order_line; both set together or both empty (ck_sol_allocation_policy_snapshot_pair, migration 029)
What they do	The policy and its version frozen when the line was created or last saved (resolve_policy_for_new_line). Allocation uses exactly this policy.
What they affect	trace.rs:299-313, policy.rs:203-236; the pick keeps the step id and version (reserve.rs:216-232).
When empty	Allocation stops: order line {id} has no frozen allocation policy. Migration 029 filled lines it could; the view allocation_policy_snapshot_unresolved_order_line lists the rest.
When you change it	A line is re-bound only when it is saved again.

7.7 Stock and location facts that decide eligibility

These are not policy fields. Page 10, section 5 lists them: location.status, location.loc_flag, location.loc_type, location.putawayzone, location.loc_category, location.abc, location.route_sequence, location.discard_lpn, pack_item.is_active, pack_item.base_qty, inventory_hold (lot, location, LPN), inventory_hold_code.active, inventory_hold_code.block_outbound_flow, and the lot dates.

8. What happens to existing orders when you change something

Change	New order lines	Existing lines (no reservation yet)	Existing reservations (picks)
Edit a draft policy	No effect (a draft cannot be bound).	None.	None.
Publish a policy	It can now be bound. Lines freeze the new version.	None.	None.
Point the SKU or owner to another policy	Use the new policy.	Keep the old policy until saved again.	Keep.
Deactivate (retire) the policy	Refused: ... is inactive ....	Bug risk: they may fail with the version mismatch (section 2).	Keep.
Edit a published policy	Not possible.	Not possible.	Not possible.
Change sku.rotation, rotate_by, min_shelf_life_on_pick, shelf_life	Read at allocation time.	Used at the next allocation.	Keep.
Change location, hold or pack data	Read at allocation time.	Used at the next allocation.	A pick that is already reserved keeps its position. Allocation does not look at a reservation again, so a hold placed later does not remove it.
Unallocate	Not relevant.	Deletes picks whose task is still Created.	Picks whose task is Assigned or later stay.

9. Known inconsistencies on this page

#	What	Where
1	Deactivate raises the policy version and frozen lines then fail with a version mismatch (to verify).	allocation_policy.rs:278-283, allocation/policy.rs:209-215
2	The editor says unreserved quantity "goes to backorder". The code has no backorder.	wms-meta-ui 001_baseline.sql:21414
3	The toggle text "merged into one task line per location" does not match what the engine does.	trace.rs:763-878, 001_baseline.sql:21431-21432 (meta-ui)
4	Stock in QC, Damage, Rtv, Destroy, Returns, Stage, Lost locations is not excluded unless a step names a location type.	inventory_balance_atp.rs:337-343
5	The comment on the view inventory_balance_atp says a switched-off hold code "blocks as before". The SQL and the Rust code treat a switched-off code as not blocking.	011_a_hold_says_what_it_forbids.sql:155-156 against :98-104 and inventory_hold.rs:227-231
6	The module notes in step.rs and allocation_step_describe.rs say a refused step is dropped. The code now refuses the whole policy.	step.rs:1-36, allocation_step_describe.rs:62-64 against policy.rs:147-156
7	The older pre-flight view allocation_policy_publication_preflight and the backfill in migration 029 do not list InTransit and Pack as refused location types. The engine refuses them.	028_...sql:60-62, 029_...sql:48-50 against step.rs:283-291
8	Delete is possible only for a draft. A policy that once was published can never be deleted. The older guide says a delete is refused when an order line uses it.	service/policy/header.rs:35-48