OAIS Reference Model (ISO 14721)

The Open Archival Information System (OAIS) Reference Model is a conceptual framework for what an archive must do — and what information it must manage — to preserve digital information and keep it usable by a defined community for the long term, regardless of the specific hardware, software, or organisational form the archive takes. It was originally developed by the Consultative Committee for Space Data Systems (CCSDS) to address long-term preservation of space science data, published as CCSDS 650.0-M (the “Magenta Book”), and standardised by ISO as ISO 14721 (first published 2003, revised 2012, most recently 2025). Despite its origin in space-data archiving, OAIS has become the de facto reference model for digital preservation across research data, library, archival, and cultural-heritage repositories generally — it supplies the shared vocabulary that CoreTrustSeal, nestor Seal, and ISO 16363 certification all build on.

OAIS is deliberately a reference model, not a piece of software or a specification an archive can “install.” It does not mandate particular file formats, storage media, or metadata schemas. Instead it defines a common set of functional entities, information-package types, and roles so that different archives — and the standards that audit them — can describe and compare their architectures using the same terms.

The six functional entities

OAIS decomposes an archive’s work into six interacting functional entities:

• Ingest — receives Submission Information Packages (SIPs) from producers, validates and quality-checks them, and transforms them into Archival Information Packages (AIPs) for long-term storage.
• Archival Storage — manages the physical and logical storage of AIPs, including media management, error checking, disaster recovery, and refreshing/migrating storage media over time.
• Data Management — maintains the descriptive and administrative metadata (the archive’s own database) that identifies and describes holdings, and supports queries against them.
• Access — handles requests from consumers, applies access controls, and produces Dissemination Information Packages (DIPs) — the form in which content is actually delivered.
• Preservation Planning — monitors the technology and user-community environment (format obsolescence, changing designated-community needs) and recommends migration, normalization, or other preservation actions.
• Administration — manages day-to-day archive operations: negotiating submission agreements with producers, system engineering, policy, and customer service.

Information packages: SIP, AIP, DIP

OAIS also defines three types of Information Packages that move through these functions, each pairing the actual content with the metadata needed to understand and preserve it: the Submission Information Package (SIP) delivered by a producer at deposit; the Archival Information Package (AIP) the archive actually stores and preserves long-term, typically enriched with fixity, provenance, context, and representation information; and the Dissemination Information Package (DIP) produced on request for a consumer. A closely related concept is the Designated Community — the specific user group the archive commits to keeping content independently understandable for, which determines how much representation information (format documentation, software dependencies, contextual metadata) the AIP needs to carry.

Relationship to CoreTrustSeal and ISO 16363

OAIS does not itself certify anything — it has no audit or assessment process. Repository trustworthiness certification schemes are built on top of it. CoreTrustSeal, the widely-adopted lightweight peer-reviewed self-assessment (16 requirements, three-year renewable term), and the more rigorous ISO 16363 (Space data and information transfer systems — Audit and certification of trustworthy digital repositories, itself a CCSDS-originated standard) both use OAIS’s functional entities and information-package model as the shared reference architecture their requirements are written against. In practice this means a repository preparing a CoreTrustSeal application or an ISO 16363 audit will typically describe its ingest workflow, storage architecture, metadata management, and preservation-planning process in OAIS terms — so understanding OAIS is a practical prerequisite to understanding what those certifications actually assess. See CASRAI’s guide to CoreTrustSeal certification for the application process, requirements, and fees.

Why it matters for research data management

For research data repositories specifically, OAIS provides the vocabulary used across funder policy, repository documentation, and certification frameworks to talk about what “long-term preservation” actually requires beyond simple storage: an ingest process that validates what comes in, metadata that makes holdings findable and interpretable independent of the depositor, a storage layer with integrity checking, an access mechanism, and — critically — an explicit preservation-planning function that watches for technology change rather than assuming today’s formats will remain readable indefinitely.

References

• ISO 14721:2025, Space data and information transfer systems — Open archival information system (OAIS) — Reference model.
• CCSDS 650.0-M-3, Reference Model for an Open Archival Information System (OAIS), Magenta Book, June 2025 (ccsds.org/Pubs/650x0m3.pdf).