The term Open Archival Information System (or OAIS) refers to the ISO OAIS Reference Model for an OAIS. This reference model is defined by recommendation CCSDS 650.0-B-2 of the Consultative Committee for Space Data Systems;[1] this text is identical to = 57284 ISO 14721:2012. The CCSDS's purview is space agencies, but the OAIS model it developed has proved useful to other organizations and institutions with digital archiving needs. OAIS, known as ISO 14721:2003, is widely accepted and utilized by various organizations and disciplines, both national and international, and was designed to ensure preservation. The OAIS standard, published in 2005, is considered the optimum standard to create and maintain a digital repository over a long period of time.
The OAIS model can be applied to various archives, e.g., open access, closed, restricted, "dark", or proprietary.[2][3]
The information being maintained has been deemed to need "long term preservation", even if the OAIS itself is not permanent. "Long term" is long enough to be concerned with the impacts of changing technologies, including support for new media and data formats, or with a changing user community. "Long term" may extend indefinitely. The OAIS defines a long period of time as any length of time that might be impacted by changing technologies and the changing of "Designated Community," e.g., any group of consumers capable of understanding the information. This length of time can be indefinite. The archive defines the community and that definition is not fixed.[2]
The "O" in OAIS represents the "open way the standard was developed", and does not represent "open access",[2] or the usage of the term open in the Open Definition or Open Archives Initiative. The "I" in OAIS represents "information", meaning data that can be shared or exchanged.[2]
In this reference model there is a particular focus on digital information, both as the primary forms of information held and as supporting information for both digitally and physically archived materials. Therefore, the model accommodates information that is inherently non-digital (e.g., a physical sample), but the modeling and preservation of such information is not addressed in detail. As strictly a conceptual framework, the OAIS model does not require the use of any particular computing platform, system environment, system design paradigm, system development methodology, database management system, database design paradigm, data definition language, command language, system interface, user interface, technology, or media for an archive to be compliant. Its aim is to set the standard for the activities that are involved in preserving a digital archive rather than the method for carrying out those activities.
The acronym OAIS should not be confused with OAI, which is the Open Archives Initiative.