This paper deals with the heuristic solution of flexible flowshop scheduling problems with unrelated parallel machines. A setup time is necessary before starting the processing of a job, where the setup time depends on the previous job. No preemption of jobs is allowed. As objective function, this paper considers the minimization of the positively weighted convex sum of makespan and the number ...

In this study, we consider a flexible manufacturing cell (FMC) processing identical parts on which the loading and unloading of machines are made by a robot. The machines used in FMCs are predominantly CNC machines and these machines are flexible enough for performing several operations provided that the required tools are stored in their tool magazines. Traditional research in this area consid...

In this paper, we study the re-entrant no-wait flexible flowshop scheduling problem with makespan minimization objective and then consider two parallel machines for each stage. The main characteristic of a re-entrant environment is that at least one job is likely to visit certain stages more than once during the process. The no-wait property describes a situation in which every job has its own ...

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...

TWO-MACHINE FLOWSHOP SCHEDULING WITH FLEXIBLE OPERATIONS AND CONTROLLABLE PROCESSING TIMES Zeynep Uruk M.S. in Industrial Engineering Advisor: Prof. Dr. Selim Aktürk Co-Advisor: Asst. Prof. Dr. Hakan Gültekin August, 2011 In this study, we consider a two-machine flowshop scheduling problem with identical jobs. Each of these jobs has three operations, where the first operation must be performed ...

This paper considers a two-stage flexible flowshop scheduling problem with no waiting time between two sequential operations of a job and no idle time between two consecutive processed jobs on machines of the second stage. We show its complexity and present a heuristic algorithm with asymptotically tight error bounds. © 2004 Elsevier B.V. All rights reserved.

This paper considers the two-stage flexible flowshop scheduling problem with availability constraints. We discuss the complexity and the approximability of the problem, and provide some approximation algorithms with finite and tight worst case performance bounds for some special cases of the problem.

In this project, we first planned to model a manufacturing system using a partial differential equation (PDE), since in the theory of traffic simulation and control, PDEs are used successfully for modeling the dynamic behavior of highway traffic. Because these traffic models show good correspondence with manufacturing systems (vehicles = products, highway = manufacturing system), PDEs can also ...

In this study, a two-machine flowshop producing identical parts is considered. Each of the identical parts is assumed to require a number of manufacturing operations, and the machines are assumed to be flexible enough to perform different operations. Due to economical or technological constraints, some specific operations are preassigned to one of the machines. The remaining operations, called ...