Preservation Policy of the Technische Informationsbibliothek (TIB) – German National Library of Science and Technology

Version 1.4 // As of: 18 February 2019 (last reviewed on 18 February 2022)

1. Introduction

The Technische Informationsbibliothek (TIB) – German National Library of Science and Technology serves as the German national library of science and technology, as well as architecture, chemistry, computer science, mathematics and physics. The library primarily provides the national and international research community and industry with literature and information. As the world’s largest specialist library in its fields, TIB is responsible for preserving recorded knowledge and for providing the latest information, both now and in the future, irrespective of time and place.

TIB is a member of the Leibniz Association.

Together, TIB, the ZBW – Leibniz Information Centre for Economics, and ZB MED – Information Centre for Life Sciences make up the Alliance of German National Specialist Libraries. The partner libraries collectively operate a digital preservation system to secure the long-term availability of their collections; they adopted a consortial Preservation Policy in 2014. The present institutional Preservation Policy of TIB fleshes out digital preservation at TIB, and is directed at employees, producers and users. The Policy is reviewed each year to identify updating requirements. Detailed information is provided on TIB’s digital preservation website.

2. Mission

2.1 Task

As the German national library of science and technology, as well as architecture, chemistry, computer science, mathematics and physics, TIB’s forward-looking services secure the infrastructural requirements for providing scientists, researchers, teachers and practitioners across Germany with high-quality information and literature.

Our globally unique collections of technical and scientific specialist and research information provide the foundation for the services offered by TIB. The core of activities at TIB centres on developing these collections in their uniqueness, preserving them as our cultural heritage, improving access to them with a reliable information infrastructure, and optimising the relevant services by engaging in research.

The task of digital preservation is documented in the TIB Strategy.

TIB acts as a depository library for research reports for various ministries and research-promoting institutions, including the Federal Ministry of Education and Research (BMBF) and the Federal Ministry for Economic Affairs and Energy (BMWi).

TIB archives university publications produced by Leibniz Universität Hannover faculties, as well as the objects stored in Leibniz Universität Hannover Institutional Repository.

2.2 Designated communities

The designated communities of the digital archive can be subdivided into producers, TIB staff, and users.

Producers submit objects to TIB.

The designated community of TIB staff includes, in particular, Digital Preservation staff as well as staff who work with the digital preservation system Rosetta.

Users of the digital archive correspond to TIB’s user groups: members of Leibniz Universität Hannover, academic and non-university research facilities, interested members of the public, and industry.

The demands placed on the digital preservation system by the designated communities are taken into account.

2.3 Collection profile and selection

As the German national library of science and technology, as well as architecture, chemistry, computer science, mathematics and physics, TIB has the task of acquiring available content in these subject areas, indexing it, making it available transregionally for the purpose of research and teaching, and ensuring its long-term accessibility. TIB pursues an e-preferred strategy, and increasingly acquires publications that are exclusively available in digital form. The proportion of non-textual media is constantly increasing.

TIB pursues the goal of being a holding library for its collections.

In some circumstances, an object may consist of more than one representation. Criteria for the choice of representations are as follows:

  • If possible, the original file provided by the producer is recorded as the MASTER representation.
  • If there is an access copy on an access platform, the access copy is recorded as the DERIVATIVE COPY representation.
  • If there is a modified copy of the MASTER, which is of use for the preservation of the objects – for example, because the sequence of individual files is portrayed – this is recorded as the MODIFIED MASTER.

In the prioritisation of digital preservation, consideration is taken not only of the collection mandate, but also of criteria such as the conservation status of the data carriers and peculiarities concerning individual partial collections such as exclusive possession in Germany/Europe/worldwide.

3. Principles of digital preservation

TIB is responsible for maintaining the long-term availability of its collections. For this purpose, TIB defines the following principles for digital preservation:

3.1 Preservation watch

The latest technology advances must be continuously observed, to be able to develop timely responses to the threat of file format obsolescence, new expectations of data consumers as well as new technologies and state-of-the-art developments.

TIB is actively involved at national and international level as a member of the digital preservation networks nestor and Open Preservation Foundation (OPF); the library encourages its staff to gain expertise by enabling them to participate in workshops and conferences, and to continuously share information with their partners.

3.2 Metadata

In the context of digital preservation, metadata ensure that an object can be located in the long term via descriptive information. In addition to this, information relevant to digital preservation about technical properties of the digital object and its production process is recorded in the metadata, and any modifications to an object are documented accordingly. The metadata are saved together with the object in a logical archival information package (AIP).

In addition to the descriptive metadata from the catalogue or other cataloguing systems, TIB records the technical, administrative, legal, structural and process-related metadata. In the process, the metadata standards Dublin Core, PREMIS-based DNX and METS are used.

3.3 Legal compatibility

TIB observes applicable legal provisions and obtains the producers’ consent to digitally preserve the data. If the corresponding rights to an object are not granted, digital preservation is carried out on the basis of statutory provisions.

3.4 Preservation levels

There are different preservation levels that describe the quality of the digital preservation action:

  • Bitstream preservation: This merely involves saving and preserving the bitstream by monitoring and exchanging the storage media. No action is taken to support preservation at the logical file format level. Bitstream preservation is the lowest preservation level.
  • Logical preservation: The long-term availability and legibility of objects is ensured at the file format level. Logical preservation ensures the executability of objects.
  • Semantic preservation: Semantic preservation ensures long-term interpretability at the contextual level. Any context information required is recorded in accompanying metadata (representation information) and checked at regular intervals to ensure it is up to date. In line with migration at the logical level, metadata can be migrated and versioned at the contextual level.

TIB seeks to achieve digital preservation at all levels for objects that the library is required to digitally preserve.

Only bitstream preservation can be offered for objects with password protection, digital rights management, signatures and other protective measures that prevent preservation action from being taken.

3.5 Preservation of data integrity

The bitstream of a saved object must be protected against unintentional modifications due to hardware defects, copying errors, human operating errors and wear and tear of the storage medium.

TIB operates its own Computer Centre, applying best practice in the process:

  • Data integrity is ensured using checksums and storage management processes.
  • TIB stores data redundantly on separate storage media.
  • The storage media are monitored and replaced as required.

3.6 Preservation of authenticity

TIB retains the original file unmodified as the Master.

All modifications are made to a copy of the original files. A modification occurs when, for example:

  • A sequence is determined for the original files.
  • The object contains confidential elements, which are removed.
  • A title page is inserted or
  • A preservation action that modifies the object, such as migration, is carried out.

The modified copy is saved as a Modified Master in addition to the Master. If changes are made to an AIP, the AIP is versioned and a new metadata encoding and transmission standard (METS) file is created. All modifications to an object are documented in the metadata.

3.7 Preservation of completeness

Objects are digitally preserved in their entirety. The structure and content of the Master are adopted in full.

3.8 Preservation of renderability

TIB has published file format recommendations for different types of publications (university publications, German research reports, audiovisual media). The file format specifications are mandatory for university publications.

The digital preservation system has a preservation planning module that can be used to create and analyse preservation plans and to carry out preservation actions.

TIB preserves the usability of objects in addition to preserving the bitstream by applying the preservation strategies of migration and emulation. Preservation actions are adapted individually to the different file format, collection and object groups using preservation plans.

3.9 Preservation of retrievability

Objects must be retrievable.

Objects in Rosetta are given a system-internal ID at the following levels:

  • Information package (SIP ID)
  • Intellectual entity (IE ID)
  • Representation (REP ID)
  • File (file ID)

Selected objects are allocated a Digital Object Identifier (DOI). Doctoral theses written at Leibniz Universität Hannover are given a Uniform Resource Name (URN).

3.10 Observance of confidentiality

The rights of use of an object are recorded in Rosetta. The licence text is stored and linked to the object in the metadata. Access rights are assigned in accordance with the licence agreement. Use restrictions are taken into consideration in the process.

  • Access to objects with a blocking period is completely blocked until the blocking period has expired.
  • Objects with restricted access can only be accessed if the access requirements are met (see 3.12 Access and use).

3.11 Documentation of processes

TIB has documented the digital preservation processes.

3.12 Access and use

Use Scenario 1: External access to access copies on access platforms
Producers and users cannot access digital objects via the access copies saved in Rosetta at present. The catalogue records and other cataloguing and access tools contain a link to the objects available to users via that link. TIB endeavours to offer users convenient access options, taking into account legal restrictions. For legal reasons, however, not all TIB objects are available online. The following use scenarios exist:

  • Freely accessible online
  • Access with a Campus Licence only
  • Access for registered users only
  • Access from a local reading room only
  • Access to a data carrier or a printed version

Use Scenario 2: Internal access to access copies in Rosetta
Internal access to access copies is dependent on a trigger event, such as:

  • The access copy available to users no longer exists.
  • The access copy available to users no longer works.

In the case of a trigger event, a search is made for the relevant AIP in the digital preservation system. The access copy deposited in the AIP is exported from Rosetta as a copy. This copy is delivered to the relevant access platform.

Use Scenario 3: Access copies are delivered to an access platform by Rosetta
For certain workflows, objects can be delivered to the respective access platform by Rosetta. 

4. Technical infrastructure

TIB’s technical infrastructure meets the requirements of the Open Archival Information System (OAIS) model. The necessary processes have been implemented in compliance with OAIS, and report functions are available.

TIB operates archival storage in its own Computer Centre.

The digital preservation system Rosetta meets the requirements applying to a digital archive:

  • Ingest (including deposit)
  • Data management
  • Archival storage
  • Administration
  • Preservation planning
  • Access 

5. Responsibilities

Digital preservation is not a temporary task, but a continuous, recurring process. Digital preservation is part of the organisational structure at TIB, and is accounted for in the budget. The Head of Conservation and Preservationis responsible for all issues concerning the preservation of long-term availability.


Thomas Bähr
Conservation of resources and long-term archiving