Scheduling two-stage hybrid flow shop with availability constraints (original) (raw)
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Scheduling hybrid flow shop problem with non-fixed availability constraints
European J. of Industrial Engineering, 2010
In this study, we deal with a k-stage hybrid flow shop scheduling problem under availability constraints (HFSPAC). In such a problem, machines are not continuously available due to preventive maintenance tasks. Our study aims to provide a good approximate solution to this specific problem with the makespan minimisation as the performance measure. Few studies exist in the literature dealing with the HFSPAC. We consider in this paper two variants to tackle this problem. In the first, the starting times of maintenance tasks are fixed, whereas in the second variant, maintenance must be performed on given time windows. In this last case, a theoretical analysis is elaborated based on the machine idle time to decide which action to perform between left-shifting or right-shifting the maintenance task in the window. Due to the NP-hardness of the HFSPAC, an approximate approach, based on a genetic algorithm (GA), is proposed to minimise the makespan. Computational experiments are performed on randomly generated instances to show the efficiency of the proposed variant (flexibility of the starting times of the maintenance tasks) in terms of makespan minimisation. Moreover, a correlation function computation is proposed to statistically analyse these experiments.
Flow shop scheduling problem with limited machine availability: A heuristic approach
International Journal of Production Economics, 2006
This paper addresses the flow shop scheduling problem with limited machine availability. In such a problem, n jobs has to be scheduled on m machines under the makespan criterion and under the assumption that the machines are not available during the whole planning horizon. Since the makespan minimization is strongly NP-hard, we propose a heuristic approach to approximately solve the problem that consists in scheduling the jobs two by two according to an input sequence, and using a polynomial algorithm. This algorithm is an extension of the geometric approach developed for the two-job shop scheduling problem. r
2020
Abstract: Flow shop scheduling problems as a typical manufacturing challenge have gained wide attention in academic fields. In this paper, we consider two stage flow shop scheduling problem in which a job block for a group job and the interval of non-availability of machine has been taken with an objective to minimize the make span. This paper provides a branch and bound technique to find optimal or near optimal sequence. This approach is very simple and easy to understand and, also provide an important tool for decision makers to design a schedule for two stage flowshop scheduling problems. The method is clarified with the help of numerical illustration. I.INTRODUCTION A flow shop is characterized by unidirectional flow of work with a variety of jobs being processed sequentially in a one-pass manner. The processing time of all the jobs are assumed to be known and all the jobs are processed in the same order in various machines. Scheduling in a manufacturing system is necessary to m...
A two-stage hybrid flowshop scheduling problem in machine breakdown condition
Journal of Intelligent Manufacturing, 2013
This paper considers a two-stage hybrid flowshop scheduling problem in machine breakdown condition. By machine breakdown condition we mean that the machine may not always be available during the scheduling period. Machine failure may occur with a known probability after completing a job. Probability of machine failure depends on the previous processed job. The problem to be studied has one machine at the first stage and M parallel identical machines at the second stage. The objective is to find the optimal job combinations and the optimal job schedule such that the makespan is minimized. The proposed problem is compatible with a large scope of real world situations. To solve the problem, first, we introduce one optimal approach for job precedence when there is one machine in both stages and then provide a heuristic algorithm when there are M machines in stage two. To examine the performance of the heuristic, some experiments used are provided as well.
International Journal of Production Research, 2011
In this paper, we consider the two-machine no-wait flow-shop scheduling problem, when every machine is subject to one non-availability constraint and jobs have different release dates. The nonavailability intervals of the machines overlap and they are known in advance. We aim to find a nonresumable schedule that minimizes the makespan. We propose several lower bounds and upper bounds. These bounding procedures are used in a branch-and-bound algorithm. Computational experiments are carried out on a large set of instances and the obtained results show the effectiveness of our method.
A heuristic method for two-stage hybrid flow shop with dedicated machines
2013
Two-stage hybrid flow shop Dedicated machine Branch and bound Makespan Heuristic a b s t r a c t This paper considers a two-stage hybrid flow shop scheduling problem with dedicated machines, in which the first stage contains a single common critical machine, and the second stage contains several dedicated machines. Each job must be first processed on the critical machine in stage one and depending on the job type, the job will be further processed on the dedicated machine of its type in stage two. The objective is to minimize the makespan. To solve the problem, a heuristic method based on branch and bound (B&B) algorithm is proposed. Several lower bounds are derived and four constructive heuristics are used to obtain initial upper bounds. Then, three dominance properties are employed to enhance the performance of the proposed heuristic method. Extensive computational experiments on two different problem categories each with various problem configurations are conducted. The results show that the proposed heuristic method can produce very close-to-optimal schedules for problems up to 100 jobs and five dedicated machines within 60 s. The comparisons with solutions of two other meta-heuristic methods also prove the better performance of the proposed heuristic method.
A Memetic Algorithm for Hybrid Flowshops with Flexible Machine Availability Constraints
2009
This paper considers the problem of scheduling hybrid flowshops with machine availability constraints (MAC) to minimize makespan. The paper deals with a specific case of MAC caused by preventive maintenance (PM) operations. Contrary to previous papers considering fixed or/and conservative policies, we explore a case in which PM activities might be postponed or expedited while necessary. Regarding this flexibility in PM activities, we expect to obtain more efficient schedule. A simple technique is employed to schedule production jobs along with the flexible MACs caused by PM. To solve the problem, we present a high performing metaheuristic based on memetic algorithm incorporating some advanced features. To evaluate the proposed algorithm, the paper compares the proposed algorithm with several wellknown algorithms taken from the literature. Finally, we conclude that the proposed algorithm outperforms other algorithms.
The hybrid flow shop scheduling problem
2010
The scheduling of flow shops with multiple parallel machines per stage, usually referred to as the Hybrid Flow Shop (HFS), is a complex combinatorial problem encountered in many real world applications. Given its importance and complexity, the HFS problem has been intensively studied. This paper presents a literature review on exact, heuristic and metaheuristic methods that have been proposed for its solution. The paper discusses several variants of the HFS problem, each in turn considering different assumptions, constraints and objective functions. Research opportunities in HFS are also discussed.