Notes from Chapter 3 of Borghoff et al.

Migration never ends. This means that organisations have to establish a proper strategy, and try to routinize it as much as possible. It helps too to migrate documents into a standard format, or as few standard formats as possible. There are fewer standard formats than non-standard formats, so the difficulty of the task is reduced. But information losses are often unavoidable. You could migrate within a product family (eg from Word 6.0 to Word 2003, say) but that depends on SW developers being committed to supporting legacy versions, which isn’t mandatory [AA: see my notes on backwards compatibility, for example.]

Advantages of migration are:

  • end users can view all documents on current rendition systems; they do not have to learn ancient apps and interfaces
  • the data in migrated documents can be copied into and manipulated by the end user’s own SW
  • less staff training needed
  • we’ll never ‘forget’ about the context or meaning of some documents, as the migration process forces us to consider the documents every few years
  • presentation of document data may even improve.

Disadvantages:

  • difficult to automate, especially for compound documents
  • errors accumulate
  • potential loss of authenticity, and ‘look and feel’
  • expensive, as all documents in a given class have to be migrated at each step.

Best to continue to store the original bitsream alongside the migrated version. (AA: this is also what other people have suggested.) Anyone who’s really desperate for authenticity can then pay for the costs to have the original app emulated. The MD needs to contain detailed migration history data.

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