A disclosed configuration is for identifying at least one failure indicating scan test cell of a circuit-under-test, CUT, the CUT having a plurality of scan test cells, is provided. The configuration comprises generating a plurality of error signatures by means of a compactor of the CUT, wherein each of the error signatures of the plurality of error signatures consist of a respective sequence of bits comprising at least one failure indicating bit, assigning each error signature to at least a first, a second and a third signature type according to a total number of failure indicating bits of the respective error signature and mapping at least a predefined minimum number of error signatures to respective scan test cells of the plurality of scan test cells. For each error signature, a priority of the mapping is determined by the signature type the respective error signature has been assigned to.