What is the difference between the types of action?

Full lifecycle actions are shown in concentric rings around the data objects at the centre of the model. These are activities which take place at any time during the digital curation lifecycle and are relevant to many different sequential actions.

For example, preservation planning should be taken into account as the data is conceptualised, when it is being preserved and when it is used and reused.

As different people may be responsible for different steps in the lifecycle there is a risk of repeated effort and an opportunity for different roles to collaborate when undertaking full lifecycle actions, for instance, sharing data on community needs between data creators, archivists, and users.

Sequential actions are the steps which are repeatedly taken to ensure that data is curated according to best practice. This sequence is not simply performed once from start to finish but forms the basis of the curation chain and continues as long as data is being curated. 

Reuse and transformation of data can lead to the creation of a subset, by selection or query, or create newly derived results which themselves need to be curated.

Occasional actions are those, which interrupt or reorder the sequential actions as a result of a decision.

For example, upon appraisal it may be decided that the data in question does not fit the remit of a digital repository, in which case data may be transferred to another archive, repository, data centre or other custodian.

In some instances data is destroyed perhaps for legal reasons. Other occasional actions are the reappraisal of data which fails validation procedures or the migration of data to a different format to protect it against hardware or software obsolescence.