OAIS and Distributed Digital Preservation in Practice An exploration of Danish and other use cases that contributed to the development of the Outer OAIS–Inner OAIS Model for Distributed Digital Preservation

The aim of the paper is to illustrate how the distributed aspects of digital preservation can be aligned in practice, with the concepts and principles of the Open Archival Information System (OAIS) Reference Model. There has been a growing awareness within the digital preservation community of the need for cooperation between organizations to address digital preservation requirements. One common example is that replicas of preservation copies of digital objects need to be independently preserved (e.g., stored, managed, monitored, documented) to ensure that at least one correct replica will survive for as long as needed. Such independence can be achieved through distributed digital preservation that relies upon specific agreements between participating and contributing organizations. The OAIS Reference Model does not address the challenges of distributed digital preservation in detail, though it acknowledges the potential benefits and the options. A model in form of an extension to the OAIS Reference Model was developed by a Danish bit repository project, as there was an urgent need for such a model. This model has evolved to the Outer OAIS–Inner OAIS (OO-IO) Model through the international project “Framework for Applying the OAIS Reference Model to Distributed Digital Preservation”. Previous papers have presented the theoretical basis for the OO-IO model as a model to describe distributed digital preservation systems in a way that conforms to the OAIS Reference Model, but practical examples of applying the model have been sparse. This paper provides detailed descriptions of how the need for the OO-IO model emerged, how it has been used for both design and audit of the Danish bit repository, how we plan to use it for minimal effort ingest, and what other use cases there are for applying the OO-IO model for distributed digital preservation purposes. This will illustrate how using the OO-IO model can assist in the analysis of complex digital preservation tasks of a distributed OAIS-conformant repository, where the OO-IO model provides terminology and contribute to break down analysis and audit questions.