ISO 14721:2003 - OAIS

NATIONAL AERONAUTICSAND SPACE ADMINISTRATION

ISO 14721:2003 OAIS - RM

6 July, 2004 Richard Ullman / 18th APAN, eScience Workshop, Cairns Austrailia

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ISO 14721:2003 - OAIS

A Reference Model for an Open Archival Information System



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ISO 14721:2003 OAIS - RM

NASA Involvement / CCSDS, ISO Status

• OAIS was developed under Consultative Committee for Space Data Systems (CCSDS)/ISO Technical Committee (TC) 20: Aircraft and Space Vehicles, and its Sub-Committee (SC) 13: Space Data and Information Transfer Systems– Promote standards for “archiving” space information.– NOT restricted to space - reference model is general

in application– Focus is digital information

• CCSDS 650.0-B-1, January 2002• ISO 14721:2003, March 2003



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ISO 14721:2003 OAIS - RM

What is an ‘Open Archival Information System Reference Model’• Open

– Reference model is open, not necessarily system or information in system

• Archival– Preserve information long enough to be concerned with the

impacts of technology, make it available to a designated community.

• Information System– Hardware, software, people and functions.

• Reference Model– Abstraction for understanding significant entities and

relationships.– Not a “reference architecture”.



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ISO 14721:2003 OAIS - RM

Information Archive Special Concerns

• The archived information must be useable by consumers who are separated in time, distance and background from the producers.

• OBSOLECENCE in years, not decades– Media, hardware and software– PRESERVATION of information MEANS keeping up

with CHANGES

• USE and USER determine acceptable packaging– Same information, different forms



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ISO 14721:2003 OAIS - RM

Benefits of OAIS Reference Model

• Vocabulary:– A common framework for discussion & description

• Completeness:– Comprehensive description of the functional parts

and roles of a digital archive [at a REFERENCE MODEL level of detail].

• Does not restrict implementation:– Map OAIS functions and roles onto YOUR archive

design, if you’ve got OAIS covered, you can be confident that your design is addressing the archive issues.



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ISO 14721:2003 OAIS - RM

Significance of OAIS

• Provides a vocabulary for discussing issues around what a digital archive is.– Producers, consumers and management

can understand each other.

• Is complete - if you’ve covered the topics in the document you can be confident that you’re system has the necessary characteristics.



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ISO 14721:2003 OAIS - RM

Figure 2-1: Environment Model of an OAIS (page 2-2)

OAIS(archive)

Producer Consumer

Management



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ISO 14721:2003 OAIS - RM

Environment Model of an OAIS: Roles

• Producer – Clients (persons or systems) who provide the

information to be preserved

• Management– Maintainers of the system, set overall policy, etc

• Consumer– Clients (persons or systems) who interact with

OAIS services to find and acquire preserved information of interest



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ISO 14721:2003 OAIS - RM

Figure 2-3: Information Package Concepts and Relationships (page 2-5)

{S,A,D} I P

Packaging Information

ContentInformati

on

Preservation

Description

Information

Description Information

about Package 1



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ISO 14721:2003 OAIS - RM

Information = Data + Representation

• Challenge to OAIS, what is the information to be preserved?

• Preservation Description Information (PDI) requires that the true nature of the content is known

• Preservation may mean changing the bits AND the associated representation information to keep pace with technology change.



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ISO 14721:2003 OAIS - RM

Preservation Description Information

• Provenance Information– Source, custody, processing algorithm, history

• Context Information– Relates Content Information to information outside the

Information Package (Documentation, citations, related information)

• Reference Information– Provides identifiers for Content (URLs, handles, service IDs)

• Fixity Information– Protects from undocumented alteration, authenticity

(checksums)



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ISO 14721:2003 OAIS - RM

Producer

OAIS

Consumer

SIP

AIP

DIP

orders

Result setsqueries

Figure 2-4: OAIS Archive External Data (page 2-8)



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ISO 14721:2003 OAIS - RM

Three Incarnations of an Information Package

• Submission Information Package– Negotiated between Producer and OAIS– Sent to OAIS by a Producer

• Archival Information Package– Information Package used for preservation– Includes complete set of Preservation Description

Information (PDI) for the Content Information

• Dissemination Information Package– Includes part or all of one or more Archival

Information Packages– Sent to a Consumer by the OAIS



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ISO 14721:2003 OAIS - RM

Figure 4-1: OAIS Functional Entities (page 4-1)

Administration

Preservation Planning

Access

Data Manage

ment

Archival

Storage

Ingest

PRODUCER

CONSUMER

M A N A G E M E N T

SIP

DIP

queriesresultsorders

AIP

DescriptiveInformation

AIP

DescriptiveInformation



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ISO 14721:2003 OAIS - RM

OAIS Functional Entities

• Ingest: Accepts Submission Information Packages (SIPs) from Producers, prepare contents for storage and management.

• Archival Storage: Storage, maintenance and retrieval of Archival Information Packages

• Data Management: Populating, maintaining, and accessing both descriptive information and internal archive administrative data.

• Access: Supports consumers in determining the existence, description, location and availability of information; allows consumers to request and receive information products



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ISO 14721:2003 OAIS - RM

OAIS Functional Entities

• Administration: Manages the overall operation of the archive system

• Preservation Planning: Monitors the environment of the OAIS and provides recommendations to ensure that the information stored in the OAIS remain accessible to the Designated User Community over the long term



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ISO 14721:2003 OAIS - RM

OAIS Responsibilities

• Negotiates and accepts Information from information producers

• Obtains sufficient control to ensure long-term preservation• Determines which communities (designated) need to be

able to understand the preserved information• Ensures the information to be preserved is independently

understandable to the Designated Communities• Follows documented policies and procedures which ensure

the information is preserved against all reasonable contingencies

• Makes the preserved information available to the Designated Communities in forms understandable to those communities



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ISO 14721:2003 OAIS - RM

Interoperability

• Motivation– Common finding aids– Common Package Descriptor schema for access– Common DIP schema for dissemination– Common SIP schema for submission to different

archives– Cost reduction through increasing the uniformity

of user interactions

• Categories of Interoperability– Independent, Federated, Shared:



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ISO 14721:2003 OAIS - RM

Reference Model Summary

• Reference model is to be applicable to all digital archives, and their Producers and Consumers

• Identifies a minimum set of responsibilities for an archive to claim it is an OAIS

• Establishes common terms and concepts for comparing implementations, but does not specify an implementation

• Provides detailed models of both archival functions and archival information

• Discusses OAIS information migration and interoperability among OAISs



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ISO 14721:2003 OAIS - RM

Follow-on Activities

• Follow-on activities coordinated by Research Libraries Group(RLG)

• OAIS implementation efforts and issues page

• Digital Repository Certification Task Force– RLG and the National Archives and Records

Administration (NARA)

• http://www.rlg.org/


ISO 14721:2003 OAIS - RM


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ISO 14721:2003 - OAIS

Status and examples



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ISO 14721:2003 OAIS - RM

Reference Model Status

• Already widely adopted as starting point in digital preservation– Digital libraries (e.g., Netherlands National

Library, KB)– Traditional archives (e.g., US National Archives)– Commercial Organizations (e.g., Aerospace

Industries Association preservation working team)

– Scientific data centers (e.g., NASA National Space Science Data Center)



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ISO 14721:2003 OAIS - RM

Selected OAIS Usage Examples

• National Library of Australia– Digital preservation policy

• Royal Library of the Netherlands (KB)– Multiple digital preservation projects using OAIS

• British National Library– Digital Preservation Strategy

• US Library of Congress• Research Library Group and OnLine Computer

Library Center– International, not for profit origination of libraries.– Promotes OAIS to it’s member libraries



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ISO 14721:2003 OAIS - RM

Selected OAIS Usage Examples-2

• InterPARES– Body of National Archives from many countries– OAIS as a starting point for archives modeling

• France ARISTOTE – digital information, including libraries and Dept of

Justice.– http://www.aristote.asso.fr/ (in french)– “astonishing unifying role” from OAIS reference model

• US National Archives and Records Administration with San Diego Super Computer Center – “Use of OAIS RM saved several weeks of effort in

specification”



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ISO 14721:2003 OAIS - RM

Selected OAIS Usage Examples-3

• System for Preservation and Access to Data and Information (SIPAD)– French space agency plasma physics archive

• US National Space Science Data Center (NSSDC)

• US National Snow and Ice Data Center (NSIDC)

• US National Oceanographic Data Center (NODC)



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ISO 14721:2003 OAIS - RM

National Space Science Data Center (NSSDC)

• NSSDC was the motivation for the OAIS model through the CCSDS. – The center is recasting it’s systems to align with the

RM– Better separation of the functionality described in

OAIS is anticipated to aid in maintaining the systems– RM helps to focus on completeness of existing

system• Emphasis on preservation components, migration

efficiency• Emphasis on finding aids, critical metadata



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ISO 14721:2003 OAIS - RM

US National Oceanographic Data Center (NODC)• One of three environmental data centers

administered by NOAA• Mapping of procedures and systems to

RM helps clarify the roles and components in the existing NODC and to identify what is missing.– Need better submission agreements– Need more detailed preservation

information



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ISO 14721:2003 OAIS - RM

National Snow and Ice Data Center (NSIDC)

• NSIDC major programs are funded by NASA, NOAA, NSF.

• OAIS RM form necessary basis for world-class archive.• OAIS RM is not sufficient. Need domain specific

standards for:– To understand what information must be preserved– To understand proper and complete descriptive information

(metadata standards)

• Use “Global Change Science Requirements for Long Term Archiving” report [USGCRP 1999] as domain aid.

Documents

ISO 14721:2003 - OAIS