18.104.22.168 Types of Information Packages
There are three subtypes of the Information Package identified in 2.2: the Submission Information Package (SIP), the Archival Information Package (AIP), and the Dissemination Information Package (DIP). The definitions of these package types in section 2 are based on the function of the archival process, which uses the package, and the translation from one package to another as it passes through the archival process. This taxonomy of Information Package types is shown in figure 4-14.
Figure 4-14: Information Package Taxonomy
It is necessary to distinguish between an Information Package that is preserved by an OAIS and the Information Packages that are submitted to, and disseminated from, an OAIS. These variant packages are needed to reflect the reality that some submissions to an OAIS will have insufficient Representation Information or PDI to meet final OAIS preservation requirements. In addition, they may be organized very differently from the way the OAIS organizes the information it is preserving. Finally, the OAIS may provide information to Consumers that does not include all the Representation Information or all the PDI with the associated Content Information being disseminated. These variants are referred to as the Submission Information Package (SIP), the Archival Information Package (AIP), and the Dissemination Information Package (DIP). Although these are all Information Packages, they differ in mandatory content and the multiplicity of the associations among contained classes.
The Submission Information Package (SIP) is that package that is sent to an OAIS by a Producer. Its form and detailed content is typically negotiated between the Producer and the OAIS. Most SIPs will have some Content Information and some PDI, but it may require several SIPs to provide a complete set of Content Information and associated PDI. The Content Information and the PDI both have associated Representation Information, and if there are multiple SIPs involved that use the same Representation Information, it is likely that such Representation Information will only be provided once to the OAIS. As another variation, since some types of PDI will apply to multiple SIPs from the same source, such PDI may be provided in a separate SIP that is without Content Information. The Packaging Information will always be present in some form.
The Descriptive Information associated with a SIP is likely to be provided prior to submitting the SIP to the OAIS, but it may be provided at any time. It may be no more than a text description with a name or title, carried by the Packaging Information, by which the SIP may be recognized.
Within the OAIS, one or more SIPs are transformed into one or more Archival Information Packages (AIPs) for preservation. The AIP has a complete set of PDI for the associated Content Information. The AIP may also contain a collection of other AIPs and this is discussed and modeled later in this subsection. The Packaging Information of the AIP will conform to OAIS internal standards, and it may vary as it is managed by the OAIS. The Descriptive Information associated with an AIP may be extensive and will be managed by the OAIS so that Consumers can find and order the Content Information of interest.
In response to an Order, the OAIS provides all or a part of an AIP to a Consumer in the form of a Dissemination Information Package (DIP). The DIP may also include collections of AIPs, and it may or may not have complete PDI. The Packaging Information will always be present in some form so that the Consumer can clearly distinguish the information ordered. The Packaging Information may take several forms depending on the dissemination media and Consumer requirements. The Descriptive Information associated with a DIP may be provided with the transfer of the DIP, or it may be provided at any time before or after the transfer. Its purpose is to give the Consumer enough information to recognize the DIP from among possible similar packages. It may be no more than a text description with a name or title, as carried by the Packaging Information, by which the DIP may be recognized.
Though the implementation of the AIP may vary from Archive to Archive, the specification of the AIP as a container that contains all the needed information to allow Long Term Preservation and access to Archive holdings remains valid. The information model for the AIP presented in 22.214.171.124 should be used as a reference to establish the types of information required to enable Long Term Preservation and access.
The exact information contents of the SIP and DIP and their relationship to the corresponding AIP are dependent on the agreements between the Archive and its Producers and Consumers. The model for both of these packages is the same as for the Information Package shown in figure 4-13 both in mandatory content and the multiplicity of the associations among contained classes. The subject of transformations between SIP and AIP and between AIP and DIP is further discussed in 4.3.