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P. 249

8.4 Time and Probabilities                                      231

            Table 8.7 Compact representation of the event log highlighting timestamps; artificial timestamps
            are used to simplify the presentation of the time-based replay approach
            Case id  Trace

                     12
                                              33
            1       a start ,a 19  ,b 25  ,d 26  ,b 32  ,d complete ,e 35  ,e 40  ,h 50  ,h 54
                                                        complete
                                                               start
                               start
                         complete
                                                    start
                                       complete
                                                                   complete
                                   start
                               28
                     17
            2       a start ,a 23  ,d start ,c 30  ,d 32  ,c 38  ,e 50  ,e 59  ,g 70  ,g 73
                                                    start
                                              complete
                                   start
                                       complete
                         complete
                                                        complete
                                                              start
                                                                   complete
                     25
                                                               50
                                              40
                                                                   55
                               32
            3       a start ,a 30  ,c start ,c 35  ,d 35  ,d complete ,e 45  ,e 50  ,f start ,f complete ,b 60  ,
                                                                         start
                                          start
                                                    start
                         complete
                                                        complete
                                   complete
                                         87
                    62
                                     80
                                                    98
                   d start ,b 65  ,d 67  ,e start ,e complete ,g 90  ,g complete
                                               start
                        complete
                               complete
            ...    ...
            Fig. 8.11 Timed replay of the first three cases in the event log: Case 1 starts at time 12 and ends
            at time 54, Case 2 starts at time 17 and ends at time 73, Case 3 starts at time 25 and ends at time 98


            running from time 25 until time 30. At time 30, c and d became enabled. However,
            as shown, c started at time 32 and d started at time 35. This implies that there was
            a waiting time of 2 before c started and a waiting time of 5 before d started. After
            completing c and d, i.e., at time 40, the first instance of e became enabled. Since
            the first instance of activity e ran from time 45 until 50, the waiting time for this
            instance of e was 45 − 40 = 5 time units. Note that from time 35 until time 45 there
            wasatokeninplace p3 (because c completed at time 35 and e started at time 45).
            However, only half of this period should be considered as waiting time for e, because
            e only got enabled at time 40 when d completed. As discussed in Sect. 7.4.3, such
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