In this paper, we propose different local search algorithms to solve a realistic variant of the flowshop problem. The variant considered here is a hybrid flexible flowshop problem with sequence-dependent setup times, and with the objective of minimizing the total tardiness. In this variant of flowshop, stage skipping might occur, i.e., not all stages must be visited by all jobs. This scheduling...

The issue of sequencing and scheduling has received considerable critical attention in many fields since the early 1950s. In this research, we studied an important production scheduling system, which generally called flexible (or hybrid) flowshop scheduling problem (FFSP or HFSP). We studied this production system with an important restriction called the no-wait. The objective was to optimize t...

this article addresses a multi-stage flowshop scheduling problem with equal number of unrelated parallel machines. the objective is to minimize the makespan for a given set of jobs in the system. this problem class is np-hard in the strong sense, so a hybrid heuristic method for sequencing and then allocating operations of jobs to machines is developed. a number of test problems are randomly ge...

The two-stage assembly flowshop scheduling problem is addressed with the objective of minimizing total tardiness. An insertion algorithm, a genetic algorithm, and a hybrid of the insertion and genetic algorithms, are developed for the problem. Conducted computational experiments reveal that the hybrid algorithm significantly outperforms the genetic algorithm while the best performing algorithm ...

The no-wait flow shop is a flowshop in which the scheduling of jobs is continuous and simultaneous through all machines without waiting for any consecutive machines. The scheduling of a no-wait flow shop requires finding an appropriate sequence of jobs for scheduling, which in turn reduces total processing time. The classical brute force method for finding the probabilities of scheduling for im...

The proposed hybrid stage shop scheduling (HSSS) model, inspired from a real case in the high-fashion industry, aims to fully exploit the potential of parallel resources, splitting and overlapping concurrent operations among teams of multifunctional machines and operators on the same job. The HSSS formally extends mixed shop scheduling (a combination of flowshop and open shop), which is able to...

The paper describes an algorithm for solving the scheduling problem of a hybrid flowshop (flowshop with multiple processors, FSMP). The algorithm is a combination of genetic algorithm and tabu search, and the batch processes it is applied on are modeled by a model of time requirements. The paper describes the algorithm and compares its performance with other optimization techniques.

A hybrid Taguchi-based genetic algorithm (HTGA) is developed for solving multi-objective flowshop scheduling problems (FSPs). Search performance is improved by using Taguchi-based crossover to avoid scheduling conflicts, and dynamic weights are randomly selected by a fuzzy inference system. The conventional approach to selecting dynamic weights randomly ignores small value for the objective whe...

We consider in this paper the two-machine no-wait flowshop scheduling problem in which each machine may have an unavailable interval. We present a polynomial time approximation scheme for the problem when the unavailable interval is imposed on only one machine, or the unavailable intervals on the two machines overlap.