Models, Sample Data and Example Projects

It is in the nature of models,samples and examples, that:

• The constituent parts are often interdependent in some way.

• Interdependencies will vary between releases and can be difficult and risky to migrate automatically.

• Their file footprint is apt to change drastically.

• They will not always be required.

• They may be moved, copied and shared.

• File paths and folder names may change in time.

• Parts of them may be re-used in other scenarios.

• They can be supported or migrated across many versions of an application.

• Many different programs may work with them and with data derived from them.

Hence, it is felt that models, samples and examples:

• Should be regarded as separate entities in their own right.

• Have a lifecycle which is likely to differ from the applications which they service.

• May be released with installations which install applications, but should be as easy as possible to divorce from such installations. Are unsuited to repair or patching by installations.

• Are risky to de-install/remove when applications are removed.

• Should be released holistically.

• Should be available separately from application installations in special cases.

• May suit release in a simple compressed archives (.zip file or self extracting executable say).

Current AVEVA MSI installations attempt to address these requirements by completely removing an installation’s ability to heal its models, samples and examples. If a new copy is required, the installation must be completely removed, and then reinstalled. Repairing will not restore models, samples or examples. Uninstalls are achieved by deleting the root folders where the models, samples and examples were deployed to. It is important to move them if they are to be retained.