Inventory Items
The Inventory Items (INV) area covers physical inventory custody: what a holding of goods is, which operations may touch it, and under what conditions.
This is a placeholder. The area is declared so that documents crossing it have something correct to point at. No use cases are written yet, and none is minted here — this convention requires each use case to contain at least one scenario, so an identifier with nothing beneath it would be an identifier the taxonomy does not admit. The first real use case takes OPS::INV::0001; until then, a document that needs to reference this ground cites the area.
Why this area is in Operations
Section titled “Why this area is in Operations”The design material for it lives under design/resources/inventory-item/, beside kanban cards and the processing network. The area is nonetheless in the OPS use-case domain, by the operator’s ruling of 2026-09-09. The two placements answer different questions: the design tree groups by what a thing is, and this taxonomy groups by the business activity a user is performing. Custody operations are things people do while running a facility.
This is stated because the mismatch looks like a mistake. It is not one, and it should not be “fixed”.
What the area will hold
Section titled “What the area will hold”An inventory item is a discrete, homogeneous, non-overlapping, located, owned quantity of goods, classified by an Item. It carries a fill state, a worthiness assessment, an expiration, and a lifecycle in which depleting and deleting are different endings.
It is changed only by a fixed set of operations, and the useful grouping is by their effect on the total quantity the system believes it holds:
| Group | Operations | Effect on total |
|---|---|---|
| Lifecycle | create, delete, write off | mints or retires the holding — write-off is the privileged form that removes stock that is still there |
| Boundary flow | replenish, consume | a real quantity crosses the system’s edge, with provenance |
| Redistribution | move, transfer, split, merge, repack | conserves quantity; changes where it is, how it is divided, or the unit it is expressed in |
| Correction | adjust quantity | sets the amount to an observed one; the only operation that changes the total without a real-world flow |
| Assessment and administration | inspect, lock, unlock, seal, unseal, adjust properties | records condition or holds the item; the quantity is untouched |
| Service | value-added services | performed on the holding — cleaning, customs clearance, fumigation |
The distinction between replenish and adjust quantity is the one to carry into the use cases: a flow has a real delta and a provenance, while a correction sets a recorded number to an observed one. They are frequently conflated, and the second is the only non-conservative operation in the set.
Two further operations — decant and consolidate, which break one holding into several with their own properties, or combine several into one — are deferred past the first version.
The area also carries license plate identity (which operations mint, maintain and retire a plate) and inventory pools.
Sources
Section titled “Sources”Drawn from the project notebook’s design material at design/resources/inventory-item/ — its index.md for what an inventory item is, and operations.md for the operation set and the grouping above. That material is a design instrument rather than a specification of the built system: its output is decisions and verified laws, not code, and nothing here describes deployed behaviour.
The placement in OPS is the operator’s ruling, 2026-09-09.
Copyright: © Arda Systems 2025-2026, All rights reserved