Cost Model for Digital Preservation (CMDP)

Property Description
ID 6
Name Cost model for Digital Preservation (CMDP)
Creator and Funding Developed by the Danish national Archives (DNA) and the Royal Danish Library in Denmark (KBDK) and funded by the Danish Ministry of Culture
Status the latest version of the CMDP tool is from 2012

The purpose is to increase cost effectiveness of digital preservation activities and to provide a basis for comparing and estimating future cost requirements for digital preservation.

Information assets Various types of office documents (unformatted/formatted text, spreadsheet, graphic, sound, video, hypertext, geodata, email) and databases. 
Activities Pre-Ingest, Ingest, Archival Storage, Preservation Planning, Data Management (partially), Administration (partially).
Resources Capital (storage equipment, migration equipment), labour (3 levels). 
Time Present, Future (25 years)
Variables Types of information assets (source/production format, destination/preservation format), volume per assts per year, type of storage system, number of copies of each information asset, salary-level, person-hours per week.
Type of tool Analysis, predication, implemented in a spreadsheet with modest use of VBA.
Availability of tools The CMDP tool and documentation is available for download at:
References Kejser, U.B., Nielsen, A. B. and Thirifays, A., Modelling the Costs of Preserving Digital Assets, in Proceedings of the UNESCO Memory of the World Conference, Vancouver, Canada, 2012: Kejser, U.B., A.B. Nielsen, and A. Thirifays, Cost Model for Digital Preservation: Cost of Digital Migration, The International Journal of Digital Curation 6, no. 1, 2011, 255-267, doi:10.2218/ijdc.v6i1.186: Kejser, U.B, Nielsen, A.B., Thirifays, A., Cost Aspects of Ingest and Normalization, Proceedings of the iPRES2011 Conference, November 1-4, 2011, Singapore, 1-10 Nielsen, A.B., Thirifays, A. and Kejser, U.B, Costs of Archival Storage, in Proceedings of the Archiving 2012 Conference, 2012, 205-210:


CMDP is a model for costing preservation of digital materials. It includes a tool that calculates present and future costs of cultural heritage institutions' digital collections based on various user inputs, such as the amount and type of data.

The model is intended for national cultural heritage institutions and was developed as a collaboration between a library and an archive. CMDP is activity based and adheres to the OAIS standard. It tries to estimate what OAIS activities and sub-activities are relevant for cost. The CMDP tool estimates costs and expresses the costs as monetary costs and/or person weeks.

CMDP was inspired by LIFE1 and developed simultaneously with LIFE2 and LIFE3 with meetings between LIFE and CMDP.

It is based on migration, normalisation at ingest as default and recurring migration. The experience of normalisation and migration at the Danish National Archives is used as the basis for estimating the cost.

CMDP is being developed iteratively and is currently missing a few OAIS entities. CMDP does not yet cover access, and only has very little financial adjustments such as depreciation. The model might be very useful if combined with KRDS approach or a simplified NASA-CET approach.