Because attributes of an event log may have a specific meaning, Interactive PMCube Explorer provides a framework to annotate the attributes of the data cube (dimensions as well as simple attributes) with semantics. For example, it is possible to mark an attribute as the start time-stamp of an event. These semantic annotations are used by Interactive PMCube Explorer to process the data, e.g. the event start time-stamp can be used to order the events in a trace. The following table gives on overview of all semantic annotations that are defined by default. However, it is possible to extend the semantics framework by providing further annotations integrated as plug-ins (see the plug-in page for a list of provided plug-ins).
| Semantic Name | Description |
|---|---|
| Identifier Semantics | |
| Case ID | Marks an attribute as the (unique) identifier for cases, or a candidate for case identifiers if the data cube model allows for more than one case attribute |
| Event ID | Marks an attribute as the (unique) identifier for events |
| Event Log ID | Marks an attribute as the (unique) identifier for the event log |
| Time Semantics | |
| Event start timestamp | Represents the point in time, when the event starts |
| Event end timestamp | Represents the point in time, when the event ends |
| Event duration | Represents the time-span from the start to the end of the event (i.e., the difference between start and end time-stamp of the event) |
| Case start timestamp | Represents the point in time, when the case starts (i.e., its first activity starts) |
| Case end timestamp | Represents the point in time, when the case ends (i.e., its last activity ends) |
| Case duration | Represents the time-span from the start to the end of the case (i.e., the difference between start and end time-stamp of the case) |
In some data cube models (e.g. Direct Access and PMC), it is possible to use different attributes as case id. In a hospital log for example, the stay of a patient in the hospital as well as the patient himself (having multiple stays in hospital) may be used as case id. In this case, both candidate attributes need to be annotated as case id in the meta-data. The case id which should be used is then selected in the OLAP query. However, some data cube models like the default PMCube model are restricted to a single case id due to the database structure. In that case, exactly one attribute must be annotated as case id which is automatically selected in the OLAP query.