UML class diagram detailing relations between operational model and meta model. Details of the class model, showing the operational model (right, in black), which contains all classes involved in the biomedical workflow and the meta model (left, in red) representing the types. All typed classes in the operational Model inherit from TypedElement, while all types in the metaModel inherit from Type. The property jsonSchema of DataType contains the metadata schema template as JSON for the specific data type. MdataField represents a metadata attribute definition. Its properties contains info about the metadata group and loop (if there is a loop) the attribute belongs to, its name and type ('STRING', 'INTEGER' or 'FLOAT') and possible ontology references. See the metadata model of Figure 3 for further details. The property jsonSchema of Data contains the metadata schema template populated with values (and units) selected by the operator when the data instance was registered in the system. MdataValues represents a single metadata attribute instance, and has properties for value and unit. Event and Process both have a property (eventState and procState) to check whether they are still active, terminated or paused. The timestamp property datetime of Event tracks when a specific event was recorded in the database. The full list of Sample properties is not shown in the picture. Each class in the diagram realizes an XTENS database table.