Cost Model for Digital Preservation

The Cost Model for Digital Preservation (CDMP) is a tool that calculates the present and future costs of three sets of activities associated with preservation of digital collections. Incorporating user inputs such as the amount and type of data, the Model addresses expenses incurred by Ingest, Archival Storage, Administration, and Preservation Planning activities from the Open Archival Information System (OAIS) Reference Model.


The tool was developed by the Royal Danish LIbrary and the Danish National Archives, with funding from the Danish Ministry of Culture's Committee for Digital Preservation.

Licensing and cost

Free – no licensing information available

Development activity

The CMDP Tool version 4 was released in September 2012. The website indicates that the tool may be developed further if funds become available.

Platform and interoperability

CMDP is constructed as a macro-enabled Microsoft Excel 97-2003 workbook.

Functional notes

The CDMP Tool can be applied to calculating the costs of the OAIS entities Ingest, Archival Storage, Administration (partially), and Preservation Planning.  The model assumes that the organisation has chosen migration as its functional preservation strategy.  Costs are stated as the time it takes an employee to perform an activity multiplied by an hourly salary; overhead costs have only been implemented indirectly as part of the salary level. Longer-term financial adjustments such as depreciation and inflation are not incorporated into the calculations.

Many of the model’s assumptions are grounded in empirical data from public archive materials, and so the model is currently most suitable for estimating the costs for this particular type of materials. In fact, the documentation warns that it will not give accurate results for all types of records.

Documentation and user support  

Documentation consists of final reports for Phase 1 and Phase 2 of the project, available in English and Danish. There is no report covering the development of versions 3 and 4. The website gives contact emails for the project team.


The spreadsheets are extremely difficult to navigate, although the complexity does allow for comprehensive transparency in the model’s calculations and assumptions.

Expertise required

Understanding of Excel functionality is helpful. Knowledge of organisational and project costs is essential.

Standards compliance

CMDP structures itself around the functional entities of OAIS and PAIMAS (Producer-Archive Interface Methodology Abstract Standard).

Influence and take-up

No information is currently available.

Last reviewed: 
25 November, 2014