1. A computer-implemented method for business process behavior conformance checking, the method comprising: obtaining a plurality of electronically-stored empirical process models, each empirical process model reflecting at least one of a plurality of logs; obtaining a plurality of electronically-stored theoretical process models; matching each empirical process model to a theoretical process model, wherein the matching comprises: generating an empirical transition matrix for each empirical process model; generating a theoretical transition matrix for each theoretical process model; and determining a decision matrix for each pair consisting of an empirical transition matrix and a theoretical transition matrix, wherein the determining a decision matrix comprises calculating a plurality of fuzzy NOT XOR values; obtaining a log for a particular process instance, wherein activities in the log for the particular process instance are unlabeled; identifying activity labels for the particular process instance; matching the log for the particular process instance to a particular empirical process; determining a particular theoretical process model that matches the particular empirical process model; computing, using at least one of the particular empirical process model and the particular theoretical process model, a diagnostic for the log for the particular process instance using an electronic processor; and outputting in human readable form the diagnostic.