You steward supplier data for a living, which means you know a truth most traceability pitches skate past: the hard part of any shared record is not the events — it is agreeing on who is who. Every network-model visibility vendor solves party identity the same way: join our platform, map your partners into our directory, and our directory becomes the authority. The authority, in other words, is the membership.
This post is about the alternative you already operate. The party identifiers a custody record needs are riding, today, in the trading documents your company already exchanges — the GLNs in your purchase orders, your suppliers' ASNs, the party records behind them in your data pool. Both sides of every trade already agreed to those identifiers, contractually, before any traceability conversation started. The record does not need a new authority. It needs to keep the one the paperwork already carries.
The three party types, quoted
The Core Business Vocabulary — CBV 2.0, the companion vocabulary to EPCIS 2.0 — defines in §7.4 exactly three source/destination types for an event, and the first is the load-bearing one:
owning_party — "the party who owns (or is intended to own) the objects at the originating/ terminating endpoint of the business transfer."
The other two are possessing_party — who holds the goods at each endpoint, which is not always who owns them, a distinction your DSD doors demonstrate daily — and location, the physical place itself. Three types, and §8.7 gives their identifier syntax: party GLNs and location GLNs — the same GS1 identifiers your item master and trading-partner records already govern (the GS1 identification machinery is worked engineer-literal at barcoding.dev, by visibility.cloud).
Now look at any supplier's despatch advice in your EDI archive. Its party loops name ship-from, ship-to, buyer and seller — GLN-qualified, per standard retail practice, in the very documents your compliance team already tests suppliers on. Every field a receiving event's party context needs is sitting in the document that announced the delivery.
The worked mapping: one receiving event, before and after
Before. A receiving event as most systems capture it: a case of GTIN A, lot L4471, scanned at your DC door, timestamped. Party context: whatever the capture system knows about itself — usually your own facility and nothing else. Who sold these goods, who owned them at origin, which supplier site despatched them: all of it lives one system away, joined later, by a person, if an investigation makes it worth the hour.
After. The same event, with the document's party loops mapped onto the standard's party fields — a conformant fixture, illustrative identifiers, real grammar: