The Current state of bounds on benchmark instances of the job-shop scheduling problem

Scheduling problems have received considerable attention over the last decade. Several sets of benchmark instances are available for comparing the quality of the different methods developed. A large number of publications achieve either the current best known or improved bounds for a subset of these instances. It is unfortunate, however, that several publications erroneously reference the current state of these bounds. This article aims to provide an accurate overview of the current state of the bounds for eight sets of benchmark instances. In addition to careful reading of the references cited, in some instances the authors were contacted directly to verify these bounds. This was necessary when the bounds were not reported in the referenced work, or when the work was unavailable to me. The article also includes a brief overview of the techniques that were used to obtain these bounds.