Data, archives and digital preservation
Migrate with evidence. Organise without losing the source. Evolve while protecting operational continuity.
At a glance
- Inventory, digitisation and optical character recognition
- Migration with document-by-document reconciliation
- Metadata, a common vocabulary and cross-collection search
- Digital preservation and integrity evidence
The need
Paper and digital records built up over years, across different systems and rules, that need to be preserved, made searchable and often migrated, without losing information or stopping operations.
Intended outcome
An inventoried, searchable and verifiable collection, where every migrated document is proven to match its source and every exception has a recorded decision.
Migrate with evidence
Document-by-document reconciliation, not sampling: an inventory validated before anything moves, counts, cryptographic checksums calculated at source, and an exception log stating who decides and by when.
Organise without losing the source
Originals and their source metadata are preserved unchanged. A separate layer maps them to a common vocabulary, with every transformation rule recorded and traceable back to the source record, so that records created under different rules can be searched together.
Evolve while protecting continuity
Migration is planned in phases and sized by the real effort of optical recognition and human checking. The source system is only switched off after the match has been formally accepted, outside critical operating periods.
Scope
- Survey and validated inventory of the collection before anything is moved.
- Digitisation and OCR (optical character recognition), measuring quality and the human checking effort.
- Phased migration: checksums calculated at source and verified at the destination for identical copies; derivatives are linked to the original through a provenance record.
- Exception handling: illegible documents, files without a matching record, legitimate duplicates and duplicates created in error.
- A two-layer metadata model: the source record preserved and a common vocabulary with recorded transformation rules.
- Cross-collection search and long-term preservation.
Deliverables
- A validated inventory, with counts by series, format and medium.
- A reconciliation report with the cryptographic checksum of every document.
- A log of exceptions and the decisions taken.
- A metadata model and documented transformation rules.
- A phased migration plan with the effort calculation shown.
- A signed acceptance record before the source is switched off.
Deployment options
On the client's premises, in a dedicated environment or in the cloud, depending on how sensitive the records are and the custody requirements. Digitisation can take place where the originals are kept.
Limits and dependencies
- A transformed document (for example, one with recognised text) does not have the same checksum as the original. That is why the original is preserved and the provenance of every derivative is recorded.
- Apparent duplicates are not deleted without documented authorisation and procedure.
- Volumes, timescales and costs are only estimated after the inventory.
- Delivery may involve digitisation partners named in the proposal.
Continuity and exit
Reversibility deliverables for this service, set out in the contract and updated before exit:
- Data and export formats
- Records, metadata and reconciliation logs in open, documented formats, with their checksums.
- Documentation
- Metadata model, transformation rules and preservation procedures.
- Configurations
- Configuration of the collection management and search systems.
- Responsibilities
- A documented chain of custody and the people responsible for exception decisions.
- Licences and contracts
- Ownership of the records identified; transfer and regularisation of the licences of the management software.
- Knowledge transfer
- Training for the records team in searching and maintaining the metadata.
Next step
Describe your records (media, approximate volumes, current systems); we will propose a survey.
Technical detail
Information for technical and procurement teams. Open each topic to read it.
Why every document is checked
Checking by sampling is cheaper and more common, but it does not prove that nothing was lost. Full reconciliation requires a prior inventory, a checksum calculated for every document at source and a procedure for what to do when the counts do not match. The difficulty lies in the exceptions, not in the calculation.
Originals and derivatives
The identity of the original is verified by its checksum. Derivatives (processed images, recognised text, preservation formats) are linked to the original through a provenance record. These are two different controls, and both are recorded.
What drives the timescale of a migration
In many collections, the timescale is driven not by data transfer but by optical recognition of non-searchable material and human review of exceptions. The plan measures these two efforts before setting dates.