The same kind of n jobs are processed one by one sequentially by a single machine and any number k of them may be processed as a batch. A setup time is necessary before the processing of the first job in a batch. The completion times of all the jobs in a batch are the same as the completion time of the last job in the batch and the processing time of the batch is the sum of a setup time and k t...

In this paper it is presented an improvement of the branch and bound algorithm for permutation flow shop problem with blocking-in-process setup times objective minimizing total time tardiness, which known to be NP-Hard when there are two or more machines involved. With that in mind, a new machine-based lower exploits some structural properties problem. A database 27 classes problems, varying nu...