So to recap, event logs are recorded usually in the XES event log format, that’s what ProM works with. An XES event log consists of traces, and a trace consists of events. The trace can have a name and other attributes. And each event has a name, the timestamp when it happened, the resource that executed this– but this is optional– and the lifecycle transition that the event records– for instance, starting or completion of an activity. Also, this attribute is optional.