The task of job shop scheduling – determining the sequence and timing of jobs on available resources – is one of the most discussed practical problems in operations management. There are many appropriate problem definitions for job shop scheduling due to the complex and dynamic nature of the problem with a large number of variables and constraints linked to jobs and resources, such as specific ...

In this paper we address a multi-objective scheduling problem for unrelated parallel machines. In unrelated parallel systems, the processing cost/time of a given job on different machines may vary. The objective of scheduling is to simultaneously determine the job-machine assignment and job sequencing on each machine. In such a way the total cost of the schedule is minimized. The cost function ...

Scheduling of multiple parallel machines in the face of sequence dependent setups and downstream considerations is a hard problem. No single efficient algorithm is guaranteed to produce optimal results. We describe a solution for an instance of this problem, in the domain of paper manufacturing. The problem has additional job machine restrictions and fixed costs of assigning jobs to machines. W...

The performance of a scheduling system, in practice, is not evaluated to satisfy a single objective, but to obtain a trade-off schedule regarding multiple objectives. Therefore, in this research, we make use of one of the multiple objective decision-making methods, a global criterion approach, to develop a multi-objective model for solving FMS scheduling problems with consideration of three per...

We consider a capacitated multi-stage operations scheduling problem encountered in a real life supply chain for disaster relief, consisting of component suppliers, a packaging contractor, local distribution centers, and many customer demand points. Each customer order has a due date and can be fulfilled by either existing inventory at distribution centers or a new assembly operation at the pack...

This scheduling model is derived from the real problem of scheduling looms in a textile industry. Jobs may be independently split over several specified machines and preemption is allowed. Deadlines are specified for each job and jobs are assumed to be available. It is shown that minimizing maximum weighted tardiness can be done in polynomial time. The case of uniform machines (as in the consid...

in this paper, we consider scheduling of project networks under minimization of total weighted resource tardiness penalty costs. in this problem, we assume constrained resources are renewable and limited to very costly machines and tools which are also used in other projects and are not accessible in all periods of time of a project. in other words, there is a dictated ready date as well as a d...

extensive research has been devoted to resource constrained project scheduling problem. however, little attention has been paid to problems where a certain time penalty must be incurred if activity preemption is allowed. in this paper, we consider the project scheduling problem of minimizing the total cost subject to resource constraints, earliness-tardiness penalties and preemption penalties, ...

In soft real-time applications, tasks are allowed to miss their deadlines. Thus, less-costly scheduling algorithms can be used at the price of occasional violations of timing constraints. This may be acceptable if reasonable tardiness bounds (i.e., bounds on the extent to which deadlines may be missed) can be guaranteed. In this paper, we consider soft real-time applications implemented on mult...

Problem of scheduling on a single machine to minimize total weighted tardiness of jobs can be described as follows: there are n jobs to be processed, each job has an integer processing time, a weight and a due date. The objective is to minimize the total weighted tardiness of jobs. The problem belongs to the class of NP-hard problems. Some new properties of the problem associated with the block...