Token-based replay

Token-based replay technique is a conformance checking algorithm [1] that checks how well a process conforms with its model by replaying each trace on the model (in Petri net notation ).

[2] Using the four counters produced tokens, consumed tokens, missing tokens, and remaining tokens, it records the situations where a transition is forced to fire and the remaining tokens after the replay ends.

Based on the count at each counter, we can compute the fitness value between the trace and the model.

The token-replay technique uses four counters to keep track of a trace during the replaying: Invariants: At the beginning, a token is produced for the source place (p = 1) and at the end, a token is consumed from the sink place (c' = c + 1).

When the replay ends, the fitness value can be computed as follows:

1 2

( 1 −

m c

Suppose there is a process model in Petri net notation as follows: The fitness of the trace (

) on the model

The fitness of the trace (

) on the model