UML class diagram of the operational model. The diagram shows the main entities of the biomedical operative model. The Project class represents the top-level component of our model. A PersonalData class contains all the sensitive information about a patient. Only authorized operators can access the identifier that maps Patient objects to PersonalData. The details of the freezer management system are not shown. A process contains sub-processes and/or events, outlining a flexible hierarchical structure. Each Data object maps to a single Event and is described by a set of MdataValues objects. The property irodsPath of File contains the logical path of the document in the iRODS file system.