In this paper, an exact geometric algorithm is presented for solving two-job sequencing and scheduling problems in flexible flow shop and job shop environments while the resources are (un)available in some time periods and processors (un)availability is the same in all work centers. This study seems utterly new and it is applicable to any performance measure based on the completion time. The in...

One of the main restrictions in scheduling problems are the machine (resource) restrictions: each machine can perform at most one job at a time. We explore machine dependencies is shop scheduling problems representing them as graphs. Our study shows that the structure of machine dependency graphs is important in the complexity analysis of shop scheduling problems. We call acyclic a shop schedul...

In most real production environment, schedules are usually inevitable with the presence of a variety of unexpected disruptions. Thus it is necessary to develop predictive/reactive schedules which can absorb disruptions while maintaining high shop performance. In this paper, a robust predictive/reactive scheduling method is developed for solving job shop scheduling in dynamic environment. It con...

Typically, general job shop scheduling problems assume that working times of machines are equal, for instance eight hours a day. However, in real factories, these working times are different because the machines may have different processing speeds, or they may require maintenance. That is, one machine may need to be operated only half day whereas other machines may have to be operated for the ...

In this paper we consider n-jobs, m-machines permutation flow shop scheduling problems. Flow shop scheduling is one of the most important combinational optimization problems. The permutation flow shop scheduling problems are NP-Hard (Non deterministic Polynomial time Hard). Hence many heuristics and metaheuristics were addressed in the literature to solve these problems. In this paper a hybrid ...

This paper proposes a new and efficient hybrid heuristic scheme for solving job-shop scheduling problems (JSP). A new and efficient population initialization and local search concept, based on genetic algorithms, is introduced to search the solution space and to determine the global minimum solution to the JSP problem. Simulated results imply that the proposed novel JSP method (called the PLGA ...

Multi-objective open-shop scheduling is definitely significant in practical. However, the research focused on multi-objective open-shop scheduling was relatively scarce. This article proposed a particle swarm optimization to address open-shop scheduling problems with multiple objectives. Originally, particle swarm optimization was invented to treat continuous optimization problems. In this pape...

In this paper a new neuro-genetic architecture is presented that solves a profit oriented dynamic job shop problem. In the job shop order acceptance and scheduling problem new jobs arrive continuously and because of insufficient job shop capacity, a selection has to be made among the offered jobs. The goal is to find an order acceptance policy, which is supported by a scheduling policy, that ma...

Job Shop scheduling problem has significant importance in many researching fields such as production management and programming and also combined optimizing. Job Shop scheduling problem includes two sub-problems: machine assignment and sequence operation performing. In this paper combination of particle swarm optimization algorithm (PSO) and gravitational search algorithm (GSA) have been presen...