Swarm Intelligence algorithms have proved to be very effective in solving problems on many aspects of Artificial Intelligence. This paper constitutes a first study of the recently proposed Unified Particle Swarm Optimization algorithm on scheduling problems. More specifically, the Single Machine Total Weighted Tardiness problem is considered, and tackled through a scheme that combines Unified P...

The vast majority of the machine scheduling literature focuses on deterministic problems, in which all data is known with certainty a priori. This may be a reasonable assumption when the variability in the problem parameters is low. However, as variability in the parameters increases incorporating this uncertainty explicitly into a scheduling model is essential to mitigate the resulting adverse...

In this paper we look at the problem where we have to schedule n jobs with release dates, due dates, weights, and equal processing times on a single machine. The objective is to minimize the sum of weighted tardiness (1|rj , pj = p| ∑ wjTj in the threefield notation scheme). We formulate the problem as a time indexed ILP after which we solve the LP-relaxation. We show that for certain special c...

Scheduling problems are important NP-hard problems. Genetic algorithms can provide good solutions for such optimization problems. In this paper, we present a genetic algorithm to solve the single machine total weighted tardiness scheduling problem, which is a strong NP-hard problem. The algorithm uses the natural permutation representation of a chromosome, heuristic dispatching rules combined w...

This paper presents a new genetic algorithm for the single machine total weighted tardiness scheduling problem, which is a strong NP-hard problem. The developmental focus has been on techniques to speed up execution in order to solve large-size problems. This genetic algorithm uses the natural permutation representation of a chromosome for encoding simplicity. Heuristic dispatching rules combin...

In the present work, SDST flow shop scheduling with minimizing the weighted sum of total weighted tardiness and makespan have been considered simultaneously. Four modified heuristic have been proposed for preliminary viable sequence. Sequence obtained from the modified heuristics is combined with the initial seed sequence of genetic algorithm and called as Genetic Algorithm (GA). Hence four dif...

The di0usion step in semiconductor wafer fabrication is very time consuming, compared to other steps in the process, and performance in this area has a signi1cant impact on overall factory performance. Di0usion furnaces are able to process multiple lots of similar wafers at a time, and are therefore appropriately modeled as batch processing machines with incompatible job families. Due to the im...

This paper presents several local search heuristics for the problem of scheduling a single machine to minimize total weighted tardiness. We introduce a new binary encoding scheme to represent solutions, together with a heuristic to decode the binary representations into actual sequences. This binary encoding scheme is compared to the usual 'natural' permutation representation for descent, simul...

We present a new mathematical model for a permutation flowshop scheduling problem with sequence-dependent setup times considering minimization of two objectives, namely makespan and weighted mean total earliness/tardiness. Only small-sized problems with up to 20 jobs can be solved by the proposed integer programming approach. Thus, an effective multi-objective immune system (MOIS) is specially ...