FAQ on modeling - Domain layer
1. How do I find suitable object types?
Although the domain-oriented metamodel is very simple, and at first glance it seems easy to create a suitable model.
However, it is very demanding to find suitable object types and tasks. The biggest difficulty will be to understand what object types actually are.
It is highly recommended to remember the definition of the term object type: "...Object types can be used to describe the type of information
that is needed to complete a task or can be provided after the task has been completed." This leads to the following consequences:
If, for example, a doctor's letter is to be modeled as a physical thing in the world, it must be taken into account that it also contains information
about the patient, case, diagnoses ... which are usually defined as separate object types. For a particular problem it may be necessary to represent
this relationship (in the form of is_part_of_relationships). Only then is it possible to adequately represent the complexity of reality.
For the reasons mentioned above, we recommend to use reference models for the domain-oriented level as far as they are available, e.g. the
domain-oriented reference model for an archive.
2. Is there a possibility to represent the organizational units graphically
(e.g. presentation of the organizational units with the corresponding tasks)?
Currently there is no possibility to display organizational units graphically. This is to avoid that the graphical model is 'overloaded'.
3. Why should message types, document types and data record types (form of representation) be defined on the technical level,
which belong more to the logical tool level?
Message types, document types and record types belong to the logical tool level. In the properties dialog of an object type you can only define
how it is represented on the logical tool level. To simplify modeling, it is also possible to create new message types, document types and record
types in this context, if the required instances of another level have not yet been modeled.
4. what should I do with the Master DBS in the Object Type/Properties Dialog/General on the domain layer?
You can assign to an object type which database system / document collection is master for this object type (relationship has_as_master
in the meta model). Master' in this context means that data may only be added, changed and deleted in this database system / document collection.
All other database systems / document collections that also store this object type must use communication between the corresponding application
modules to compare their data with this database system / document collection when data is changed, added or deleted, otherwise data integrity
cannot be guaranteed. (This is of course particularly problematic with document collections!). If both application modules are computer-based,
event message types are communicated, if one of the application modules is paper-based, event document types are communicated.