ISO 14721:2003 specifies a reference model for an open archival information system (OAIS). The purpose of this ISO 14721:2003 is to establish a system for archiving information, both digitalized and physical, with an organizational scheme composed of people who accept the responsibility to preserve information and make it available to a designated community.

This reference model addresses a full range of archival information preservation functions including ingest, archival storage, data management, access, and dissemination. It also addresses the migration of digital information to new media and forms, the data models used to represent the information, the role of software in information preservation, and the exchange of digital information among archives. It identifies both internal and external interfaces to the archive functions, and it identifies a number of high-level services at these interfaces. It provides various illustrative examples and some "best practice" recommendations. It defines a minimal set of responsibilities for an archive to be called an OAIS, and it also defines a maximal archive to provide a broad set of useful terms and concepts.

The OAIS model described in ISO 14721:2003 may be applicable to any archive. It is specifically applicable to organizations with the responsibility of making information available for the long term. This includes organizations with other responsibilities, such as processing and distribution in response to programmatic needs.