This paper considers a complex job shop problem with reentrant flow and batch processing machines. A modified shifting bottleneck heuristic (MSB) is considered for generating machine schedules to minimize the total weighted tardiness. We observe that the MSB could produce infeasible schedules where cyclic schedules are found. A cycle elimination procedure is proposed to remove the possibility o...

The problem of determining a schedule of jobs with unit time lengths on a single machine that minimizes the total weighted earliness and tardiness penalties with respect to arbitrary rational due dates is formulated as an integer programming problem We show that if the penalties meet a certain criterion called the Dominance Condition then there exists an extremal optimal solution to the LP rela...

In this paper we study the permutation #owshop scheduling problem with an increasing and decreasing series of dominating machines. The objective is to minimize one of the "ve regular performance criteria, namely, total weighted completion time, maximum lateness, maximum tardiness, number of tardy jobs and makespan. We establish that these "ve cases are solvable by presenting a polymonial-time s...

In this note, we consider a single machine scheduling problem with generalized total tardiness objective function. A pseudo-polynomial time solution algorithm is proposed for a special case of this problem. Moreover, we present a new graphical algorithm for another special case, which corresponds to the classical problem of minimizing the weighted number of tardy jobs on a single machine. The l...

The study deals with scheduling a set of independent jobs with unequal release dates to minimize total weighted tardiness on a single machine. We propose new dominance properties that are incorporated in a branch and bound algorithm. The proposed algorithm is tested on a set of randomly generated problems with 10, 15 and 20 jobs. To the best of our knowledge, this is the first exact approach th...

Even though a very large number of solution methods has been developed for the jobshop scheduling problem, the majority are designed for the makespan criterion. In this paper, we propose a general approach for optimizing any regular criterion in the job-shop scheduling problem. The approach is a local search method that uses a disjunctive graph model and neighborhoods generated by swapping crit...