The XES meta model shown in Fig. 4.7 does not prescribe a concrete syntax. In principle many serializations are possible. However, to exchange XES documents, a standard XML serialization is used. Figure 4.8 shows a fragment of the XES XML serialization of the event log of Table 4.1. In the example XES log, three extensions are declared: Concept, Time, and Organizational. For each of these extensions
a shorter prefix is given. These prefixes are used in the attribute names. For example, the Time extension defines an attribute timestamp. As shown in Fig. 4.8, this extension uses prefix time, therefore the timestamp of an event is stored using the key time:timestamp