Physical Item Instance

Master identifier and issuing authority

Which identifier is authoritative for this item, who issued it, under which scheme and syntax, and what uniqueness guarantees apply. ISO/IEC 15459-4 specifies a unique, non-significant string for individual items issued under a registered issuing agency; GS1 expresses the same idea as a primary key plus serial qualifier.

1. Which single identifier is the authoritative master identifier for this item, and which agency or system issued it? identity
2. What uniqueness and non-reuse guarantee does the issuing scheme give, and over what period? constraint
3. If no authoritative external identifier exists, which locally minted identifier is used and how is its provenance recorded? provenance
4. In which syntaxes may this identifier legitimately be expressed for exchange? interoperability

Identity marks and data carriers

The physical realisation of identity on the thing itself: marking method, placement, durability, legibility, and the machine-readable carrier. IEC 61406-1 requires a globally unique identification link, machine readable via 2D symbol or NFC and attached to the individual unit; ESPR-driven passports require a data carrier on the product.

1. How is each identifier physically applied to the item and where on the item is it placed? composition
2. Is the mark expected to survive the item's service life, and what happens when it becomes illegible or is removed? quality
3. What exactly does the machine-readable carrier encode, and does it resolve to a live information service? interoperability
4. Who is permitted to apply, alter or remove an identity mark on this item? authority

Identifier resolution, aliases and collisions

How an observed identifier is resolved to exactly one item record, how multiple scheme identifiers for the same thing are related, and how duplicates, cloned identifiers and merge/split situations are handled.

1. Given a scanned or quoted identifier, what procedure resolves it to at most one item record? validation
2. Which additional identifiers are asserted to designate this same item, and on whose authority? relationship
3. What is done when two physical things present the same identifier, or one thing presents conflicting identifiers? exception
4. How are duplicate records merged or an erroneously merged record split, and how is the prior identifier preserved? lifecycle

Legibility, cloning risk and distinguishing marks

Object ID requires inscriptions and markings, distinguishing features and photographs because unique numbers can be copied, lost or never assigned. A cloned serial or unreadable tag does not by itself prove a second item, nor does it destroy the original item's identity. Condition of the mark is evidence about identification quality, not a new identifier.

1. Is each identifier mark currently legible, damaged, over-labelled, removed or only photographically documented, and when was that assessed? quality
2. What Object ID-style distinguishing features, inscriptions or damage patterns uniquely describe this object even if serials are absent or cloned? identity
3. Is there evidence that a presented identifier is cloned, counterfeit, reused or bound to another item, and what is the confidence and evidence of that suspicion? security

Digital link, passport and shell

IEC 61406-1 defines the IL string as a URL that is both the globally unique identification of a physical object and a pointer to related information. Schema.org requires that a GS1 Digital Link containing serial AI 21 appear only on IndividualProduct. ESPR establishes a digital product passport with a unique product identifier, unique operator identifier and unique facility identifier, accessed via a data carrier on the product. IDTA AAS gives the asset a recommended globalAssetId (IEC 61406 format) and optional specificAssetIds, while the Administration Shell has a separate mandatory id. These are representations and links, not a second physical item.

1. What resolvable IRI or URL currently identifies this physical object (IEC 61406 IL, GS1 Digital Link with AI 21, DPP unique product identifier), and does it encode instance grain rather than type or lot? identity
2. Which digital representations (DPP, AAS, other twin) describe this item, what are their own identifiers, and which of those identifiers are explicitly not the item master? interoperability
3. If a DPP or similar passport exists, what unique operator identifier and unique facility identifier are bound to this item instance, and at which production event? provenance

Instance-of-type reference

The resolved reference from this individual to its product type or configuration, and the confidence in that resolution. schema.org places IndividualProduct under Product with isVariantOf pointing at a ProductModel; EPCIS keeps class-level identification separate from instance-level identification.

1. Which type or configuration record does this item instantiate, and in which sibling model is it mastered? classification
2. On what evidence was the type resolved: marking, documentation, expert determination or inference? evidence
3. In what respects does this specimen deviate from its type specification, and are those deviations authorised? constraint
4. How is an item that cannot be assigned to any known type represented without inventing one? exception

Individuation and identity continuity

The rules deciding what counts as one item and whether identity survives repair, component replacement, reconfiguration, division or joining. No consulted standard settles this; CIDOC CRM anchors documentation units and composition, and PROV offers specializationOf/alternateOf to relate records without asserting sameness.

1. What physical criterion individuates this thing as one item rather than a part, a set or a quantity? definition
2. Which changes preserve identity and which terminate it and create a successor item? lifecycle
3. When an item is split, merged or rebuilt, how is lineage to predecessor and successor items recorded? provenance
4. Who decides a contested continuity case and by what documented rule? authority

Configuration and lot inputs

A product configuration may classify a configured instance (variant-instance boundary). A lot or batch identifier is not an instance identifier; Schema.org places lot-bearing Digital Links on SomeProducts unless there is only a specific product. IEC 61406-2 separately treats lots/batches. Lot membership and configuration are classification or provenance facts on the instance.

1. What product configuration or variant, if any, classifies this configured instance, and is that a sibling configuration master rather than an extra serial? classification
2. From which lot or batch was this instance produced or separated, and is that lot used only as provenance rather than as the item identifier? provenance
3. Which instance-level master data attributes (EPCIS ILMD such as expiration) belong to this instance rather than to the type, and what is their validity window? classification

Measured attributes and measurement context

Quantities measured on this individual (mass, dimensions, readings) together with unit, method, instrument, uncertainty and the separation of measurement time from record time.

1. Which properties are measured on this specimen rather than inherited from its type? measurement
2. By what method and instrument was each value obtained, and with what stated uncertainty? quality
3. When was the value measured and when was it recorded, and which one governs currency of the value? temporal
4. How are conflicting measurements of the same property at the same time reconciled? exception

Material content and substances of concern

What this specimen is actually made of, referenced to material classes rather than restated, including substance declarations that product-passport regimes attach to the individual product.

1. Which material classes constitute this item, and in what proportions where known? composition
2. Which declarable or hazardous substances are recorded for this individual, and under which regime? requirement
3. Is the material content declared, tested or inferred from the type specification? evidence

Component membership in an assembly

Whether this item is currently or was formerly installed in a parent item, in what position or role, and over what period. The assembly graph itself is mastered by WM-OBJ-012; EPCIS AggregationEvent and CIDOC P46 supply the parent/child semantics.

1. Which parent item does this item form part of at a given instant, and in what position or role? composition
2. Which events installed or removed this item from a parent, and who performed them? event
3. Do child components retain their own instance identity while installed, or are they absorbed into the parent? identity
4. Where is the full assembly structure mastered, and which parts of it may be cached here? interoperability

Boundary against quantity, batch and bulk

The rule that refuses instance identity to matter with no individuating boundary. ISO 22095 chain-of-custody models such as mass balance and controlled blending explicitly do not preserve one-to-one identity, and EPCIS provides class-level quantity fields precisely for this case.

1. On what test is a candidate refused an item-instance record and represented as a quantity or batch instead? decision
2. How are non-instance contents held inside this item (fluids, consumables, loose parts) represented without minting instances? composition
3. Which chain-of-custody model applies to the material in or around this item, and does it preserve identity? constraint

Lifecycle status and permitted transitions

The current governed status of the item, the transition that produced it, and the constraints on legal transitions. EPCIS disposition expresses the business state of an object after an event, and persistentDisposition expresses states that survive later events.

1. What is the item's current lifecycle status and which event set it? state
2. Which status transitions are permitted from the current status, and which are forbidden? constraint
3. Which states persist across subsequent events until explicitly cleared, and who may clear them? lifecycle
4. How is an item represented whose status is genuinely unknown, and for how long may that persist? exception

End of life, loss and disposal

How the item leaves tracked existence: destruction, recycling, permanent loss, theft or export beyond the record's reach, and what evidence closes the record without deleting it.

1. By what mode did the item leave tracked existence, and when? lifecycle
2. What evidence proves the terminal event, and who issued it? evidence
3. Can a terminal state be reversed, for example when a lost item is recovered, and how is the gap recorded? exception
4. How long is the record retained after the item ceases to exist, and under what obligation? retention

Loss, theft, seizure, recovery and deaccession

Object ID exists because stolen and trafficked objects cannot be recovered without documentation, photographs and distinguishing features; INTERPOL and customs use that documentation. Unknown whereabouts is not the same as non-existence. Seizure, loan, exhibition and deaccession change custody or collection membership without necessarily destroying the object. These states lack a single global code list and must be recorded as explicit exceptional statuses with evidence.

1. Is the item missing to its holder, reported stolen, seized by authority, in dispute, or merely not recently observed, and when was that status asserted? exception
2. If previously missing or stolen, when was it recovered or returned, by whom, and did identity, condition or custody need re-validation? event
3. Has a museum, court or owner deaccessioned, forfeited or legally abandoned the item, and does that end title, custody, or only collection membership? ownership

Condition assessment and intervention history

Condition as an assessed, dated judgement bound to a scale, assessor and method, together with the repairs, restorations and modifications that altered the individual. CIDOC CRM binds condition states to time-spans; schema.org itemCondition is a commerce enumeration and is not equivalent.

1. What condition grade is asserted, on which named scale, and by whom? quality
2. By what method was condition determined: visual inspection, measurement, functional test or declaration? measurement
3. Which interventions have been performed on this item, by whom, and what did they change? process
4. How stale may a condition assessment be before it must not be presented as current? temporal

Authenticity verification and cloned-identifier handling

Checks that bind the physical thing to the record: mark inspection, carrier verification, tamper evidence and cryptographically verifiable credentials, plus the handling of negative results and duplicate presentations.

1. Which verification checks were performed on this item, by whom, and with what result? validation
2. Which verifiable credentials assert facts about this item, and what is their current status? evidence
3. What happens when verification fails or when the same identifier is presented on two physical things? exception
4. What tamper-evidence exists on marks and carriers, and how is tampering recorded? security

Location fix and observation quality

A dated statement of the item's whereabouts resolved against a place reference, distinguishing the point of observation from the business location asserted afterwards, and carrying precision and source.

1. Where is the item now believed to be, on the strength of which observation? spatial
2. Is a given location statement the point where the observation happened or the location the item is considered to be at afterwards? definition
3. How was the whereabouts established: scan, sensor, sighting, declaration or inference? provenance
4. How are contradictory or physically impossible location statements resolved? exception

Containment and carrier context

What the item was inside when observed: a handling unit, a vehicle, a room or another item, and how aggregation and disaggregation change that context without changing item identity.

1. What container, handling unit or carrier was the item inside at a given instant? relationship
2. Which aggregation or disaggregation events changed the item's containment, and when? event
3. How deep may containment nest, and how is the outermost location derived from the innermost item? composition
4. Which model masters the container itself, so that its contents are not restated here? interoperability

Custody record and transfer

Periods during which a named party held the item, the basis of holding, and the transfer events between holders, aligned with ISO 22095 custody terminology and EPCIS source/destination and shipping/receiving semantics.

1. Who holds the item now, since when, and on what basis (ownership, lease, loan, bailment, transport)? ownership
2. Which transfer moved custody from one party to another, and was it acknowledged by both sides? process
3. What prevents two open custody records existing at once, and how is an overlap corrected? constraint
4. How are custody gaps recorded when the holder is genuinely unknown for a period? exception

Ownership and rights reference

The reference to legal title and encumbrances held in the ownership sibling model, and the rule that possession does not imply title. CIDOC CRM distinguishes current owner (P52) from keeper (P49); ISO 55000 frames value-bearing entities as assets of an organization.

1. Who is recorded as owner of this item, and in which model is that assertion mastered? ownership
2. When holder and owner differ, which record governs each type of decision about the item? authority
3. What claims, liens, restitution claims or export restrictions limit dealings with this item? constraint

Event capture and correction

The event structure that records what happened to the item, why, where and how, and the rules for idempotent capture, correction and retraction of events that must not be silently overwritten.

1. What minimum fields must an event carry to be a valid statement about this item? requirement
2. What business step and resulting disposition does the event assert, and from which vocabulary? classification
3. How is an erroneous event corrected or retracted without destroying the original assertion? exception
4. How are duplicate captures of the same real-world occurrence detected and collapsed? validation

Time semantics and ordering

The separation of when something happened from when it was recorded, the required timestamp form, and how ordering is decided when clocks disagree. RFC 3339 requires a stated offset to UTC, with 'Z' for zero offset and '-00:00' where the local offset is unknown; EPCIS carries eventTime, eventTimeZoneOffset and repository recordTime separately.

1. For each statement, when did the fact occur and when was it observed or ingested? temporal
2. How is the order of statements decided when event times are equal, missing or inconsistent with record times? constraint
3. How is an imprecise or historical time expressed without fabricating precision? quality

Event dimensions

EPCIS 2.0 records What, When, Where, Why and How. Event types are ObjectEvent, AggregationEvent, TransactionEvent, TransformationEvent and AssociationEvent. When includes event time and record time. Why includes bizStep, disposition and persistentDisposition. How includes sensor elements in 2.0. Instance EPCs must not be mixed up with class-level EPCs. Event hash identifiers and business-transaction hash URIs appear in CBV 2.0.

1. What events in this item's history are known, with type, action, event time, record time, event id or hash, and which identifier of the item was observed? event
2. Was each event about this specific instance, a class/lot of which this instance is a member, or mixed, and is class-level inference flagged as inferred? validation
3. What How-dimension sensor measurements accompanied the event, with quantity, unit, sensor id, and measurement time? measurement

Origin and chain of custody provenance

The origin of the individual (maker, place, date of production or first observation) and the ordered chain of custody from origin to the present, including declared gaps. PROV-O supplies generation, derivation and attribution; ISO 22095 supplies the custody model vocabulary.

1. Who produced this individual, where and when, and how is that known? provenance
2. What is the ordered chain of holders from origin to now, and where are the gaps? relationship
3. Which chain-of-custody model does the chain claim to satisfy, and is that claim independently checked? validation
4. How are contested or fabricated provenance claims flagged without deleting them? exception

Attestations, evidence quality and conflicting claims

How each claim about the item is supported, who vouches for it, how strong that support is, and what happens when two credible sources disagree.

1. Which claim does each item of evidence support, and who issued that evidence? evidence
2. How is evidence strength graded, and what is the minimum grade for a claim to be published externally? quality
3. How is a credential's revocation, suspension or expiry reflected in claims that relied on it? validation
4. When two sources make incompatible claims about the item, which prevails and on what recorded rule? decision

Mastership, authority and record lifecycle

Which system and which party master this record, who may assert or change each part of it, and how record versions relate to the physical thing they describe.

1. Which system of record masters this item record, and which fields are copies from elsewhere? authority
2. Which roles may create, amend or retire each class of statement about the item? access
3. How is a change to the record distinguished from a change to the physical thing? definition
4. What retires the record itself, as opposed to ending the item's life? lifecycle

Access scoping and disclosure views

Which audiences may see which parts of the record, including a public identity view that deliberately withholds whereabouts and holder, and the exceptions that override the default.

1. What is the default visibility of each bundle and layer for a party with no explicit grant? access
2. Which fields may appear in a publicly resolvable view of the item, and which must never appear? privacy
3. Under what exceptions may withheld data be disclosed, to whom, and with what record? exception
4. How are access grants issued, time-boxed and revoked, and what happens to data already disclosed? security

Privacy exposure and retention

When item data becomes personal data, and how retention duties for traceability are reconciled with data-protection limits. GDPR applies to processing of personal data about identifiable natural persons; item records routinely carry holder identity, ownership history and movement traces.

1. Which fields link the item to an identifiable natural person, directly or by combination? privacy
2. How long is each class of item data retained, on what legal or contractual basis? retention
3. How is an erasure request reconciled with traceability, safety or product-passport duties that require retention? exception
4. What correlation risk arises from a persistent, publicly resolvable item identifier, and how is it mitigated? security

Identifier and vocabulary alignment

Mappings from this model's terms to external vocabularies (GS1 EPCIS/CBV, GS1 Digital Link, schema.org, IEC 63278-1, CIDOC CRM, PROV-O) recorded as alignments with known conflicts, never as conformance claims.

1. For each external standard, which of its terms does a given element of this model map to, and is the mapping exact, broader or narrower? interoperability
2. Where do external standards contradict one another about the same fact, and how is the contradiction recorded rather than hidden? constraint
3. Which version of each external vocabulary is the mapping valid against, and how is drift detected? provenance
4. What evidence would be required before claiming conformance to a given external standard? validation

Exchange projections and external obligations

The outbound payloads built from this model (visibility events, product-passport content, credential presentations) and the obligations that attach when data is published to an external regime.

1. Which outbound projection is required for a given consumer, and which fields does it draw from? interoperability
2. Does an external payload bind to the item instance, to a batch or to the model, and is that level stated explicitly? identity
3. What accuracy, availability and update duties attach once data is published to an external regime, and who is responsible? requirement
4. How is divergence detected between a published projection and the current internal record? quality