Inadvertent Time Travel

Description

  • Entries in a log are recorded with an incorrect timestamp due to the ‘proximity’ of the correct value to the erroneously recorded value
    • ‘Proximity’ may be
      • User pressing ‘wrong’ keys that are adjacent to correct key
      • User failing to notice/properly record change of day (‘midnight’ issue) so time part is correctly captured but date part incorrectly captured
      • Also affects change of year, month, …

Affect

  • Incorrectly discovered process models
    • Models will allow behaviours that did not actually occur
  • Negative affect on accuracy of time-related performance analysis
    • Working time & Waiting time

Data Quality Issues

I16 - Incorrect data: timestamp
  • The incorrect timestamp values introduced into an event log through the occurrence of this pattern negatively impacts the attribute accuracy of the log in that the temporal ordering of the events no longer reflects the actual ordering of events.

Manifestation and Detection

  • Pattern signature — Misplaced events – given two activities a1 and a2 with a strict temporal ordering property such that a1 should always occur before a2, there exists at least a case with two events with activities a1 and a2 with incorrect ordering.
 

Remedy

  • Requires knowledge of the logical order of events
  • Exploit this knowledge to locate traces that violate ordering restrictions
  • Apply remediations for standard proximity errors
    • adding or subtracting one day from the timestamp, or
    • flipping the value of the timestamps based on proximity of the keys in a standard keyboard layout
  • When changing timestamps check whether this indeed fixes the logical ordering error(s)

Side-effects of Remedy

  • Could result in interesting, deviant behaviour being lost.