A scheduling system is proposed and developed for a special type of flow shop. In this flow shop there is one machine at each stage. A job may require multiple operations at each stage. The first operation of a job on stage j cannot start until the last operation of the job on stage j-1 has finished. Preemption of the operations of a job is not allowed. The flow shop that we consider has anothe...

Considering the standard particle swarm optimization (PSO) has the shortcomings of low convergence precision in job shop scheduling problems, the job shop scheduling solution is presented based on improved particle swarm optimization (A-PSO). In this paper, the basic theory of A-PSO is described. Also, the coding and the selection of parameters as well as the decoding of A-PSO are studied. It u...

A fast branch and bound algorithm for the job-shop scheduling problem has been developed. Among other hard problems it solves the 10 x 10 benchmark problem which has been open for more than 20 years. We will give a complete description of this algorithm and will present computational results.

In this paper, we present on a periodic job shop scheduling problem (PJSSP) based on the periodic event scheduling problem (PESP), which is different from cyclic scheduling. The PESP schedules a number of recurring events, such that each pair of events fulfills certain constraints during a given time period. To solve such a hard PJSS problem, we propose a hybrid algorithm, namely EM–SA, which i...

The flexible job shop scheduling problem (FJSP) is one of the most difficult NP-hard combinatorial optimization problems. It is extremely difficult to solve the FJSP with the disturbances of manufacturing environment, which is always regarded as the flexible job shop online scheduling problem. This paper proposes a new method based on Process-Tree to solve this type of scheduling problem. Proce...

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...

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 ...

When using a constructive search algorithm, solutions to scheduling problems such as the job shop and open shop scheduling problems are typically represented as permutations of the operations to be scheduled. The combination of this representation and the use of a constructive algorithm introduces a bias typically favouring good solutions. When ant colony optimisation is applied to these proble...