The m-machine no-wait flowshop scheduling problem is addressed where setup times are treated as separate from processing times. The objective is to minimize total tardiness. Different dispatching rules have been investigated and three were found to be superior. Two heuristics, a simulated annealing (SA) and a genetic algorithm (GA), have been proposed by using the best performing dispatching ru...

The multi-processor total tardiness problem (MPTTP) is an -hard scheduling problem, in which the goal is to minimise the tardiness of a set of jobs that are processed on a number of processors. Exact algorithms like branch and bound have proven to be impractical for the MPTTP, leaving stochastic local search (SLS) algorithms as the main alternative to find high-quality schedules. Among the avai...

Previous research in the single machine total weighted tardiness problem (SMTWTP) has led to the proposition of effective local search strategies. At least existing benchmark instances from the literature do not pose a challenge for state-of-the-art algorithms. This paper describes the proposition of two classes of novel instances for the single machine total weighted tardiness problem. In resp...

This paper presents a tabu search approach to minimize total tardiness for the job shop scheduling problem. The method uses dispatching rules to obtain an initial solution and searches for new solutions in a neighborhood based on the critical paths of the jobs. Diversi"cation and intensi"cation strategies are suggested. For small problems the solutions' quality is evaluated against optimal solu...

This article considers the problem of scheduling preemptive open shops to minimize total tardiness. The problem is known to be NP-hard. An efficient constructive heuristic is developed for solving large-sized problems. A branch-and-bound algorithm that incorporates a lower bound scheme based on the solution of an assignment problem as well as various dominance rules are presented for solving me...

This paper presents several local search meta-heuristics for the problem of scheduling a single machine to minimise total weighted tardiness. A genetic algorithm for the static single machine total weighted tardiness problem is presented, and a multi-start version named metaGA is proposed. The obtained computational results permit to conclude about their efficiency and effectiveness. The resolu...

We study the problem of scheduling jobs on a serial batching machine to minimize total tardiness. Jobs of the same batch start and are completed simultaneously and the length of a batch equals the sum of the processing times of its jobs. When a new batch starts, a constant setup time s occurs. This problem 1|s-batch| P Ti is known to be NP-Hard in the ordinary sense. In this paper we show that ...

We present new MIP formulations for the single machine total weighted tardiness problem. These formulations are based on a partition of the time horizon into intervals. This partition is done in such a way that the problem reduces to the problem of assigning jobs to intervals. This leads to a compact formulation that can be solved with standard integer programming techniques. We also introduce ...