4.2 Event Logs
Table 4.1 shows a fragment of the event log already discussed in Chap. 1. This
table illustrates the typical information present in an event log used for process
mining. The table shows events related to the handling of requests for compensation. We assume that an event log contains data related to a single process, i.e., the
first coarse-grained scoping step in Fig. 4.1 should make sure that all events can be
related to this process. Moreover, each event in the log needs to refer to a single process instance, often referred to as case. In Table 4.1, each request corresponds to a case, e.g., Case 1. We also assume that events can be related to some activity. In Table 4.1, events refer to activities like register request, check ticket, and reject. These assumptions are quite natural in the context of process mining. All mainstream process modeling notations, including the ones discussed in Chap. 2, specify a process as a collection of activities such that the life-cycle of a single instance is described.Hence, the “case id” and “activity” columns in Table 4.1 represent the bare minimum for process mining. Moreover, events within a case need to be ordered. For
example, event 35654423 (the execution of activity register request for Case 1) occurs before event 35654424 (the execution of activity examine thoroughly for the
same case). Without ordering information, it is of course impossible to discover
causal dependencies in process models.