I would find it helpful to clarify what would count as a long-term success of the collections in order to clarify what counts as sustainability. For example, a minimal goal for the catalogue of collections would be sustained growth over time as a pooled knowledge resource, relative to (our best knowledge of) the number of collections that exist. However, each collection record in the catalogue is a complex object with multiple metadata fields. Each collection record may also be valuable for multiple uses, which depend in contextual ways on the accuracy and completeness of the record metadata. Some basic criteria for growth over a time unit would then be:
- The number of unique collection records increases
- The proportion of collection records with valid and accurate metadata does not decline
- The fitness-for-use of the pooled knowledge increases (indexed relative to one or more uses and associated quality standards)
The costs of achieving sustained growth will depend on who’s responsible for contributing time and resources to each criteria, excluding the creation and maintenance of the underlying technical infrastructure of the catalog. Determining what’s sustainable as a division of labor in this regard is highly dependent on the choice of governance arrangement. But I think it’s important to keep in mind where these different contributions are supposed to happen to understand at a coarse-grained level what volunteer versus paid time are needed for sustainability.