217 research outputs found
Exact and Heuristic Algorithms for the Job Shop Scheduling Problem with Earliness and Tardiness Over a Common Due Date
Scheduling has turned out to be a fundamental activity for both production and service organizations. As competitive markets emerge, Just-In-Time (JIT) production has obtained more importance as a way of rapidly responding to continuously changing market forces. Due to their realistic assumptions, job shop production environments have gained much research effort among scheduling researchers. This research develops exact and heuristic methods and algorithms to solve the job shop scheduling problem when the objective is to minimize both earliness and tardiness costs over a common due date. The objective function of minimizing earliness and tardiness costs captures the essence of the JIT approach in job shops. A dynamic programming procedure is developed to solve smaller instances of the problem, and a Multi-Agent Systems approach is developed and implemented to solve the problem for larger instances since this problem is known to be NP-Hard in a strong sense. A combinational auction-based approach using a Mixed-Integer Linear Programming (MILP) model to construct and evaluate the bids is proposed. The results showed that the proposed combinational auction-based algorithm is able to find optimal solutions for problems that are balanced in processing times across machines. A price discrimination process is successfully implemented to deal with unbalanced problems. The exact and heuristic procedures developed in this research are the first steps to create a structured approach to handle this problem and as a result, a set of benchmark problems will be available to the scheduling research community
Bütünleşik tedarik zinciri çizelgeleme modelleri: Bir literatür taraması
Research on integration of supply chain and scheduling is relatively recent, and
number of studies on this topic is increasing. This study provides a comprehensive
literature survey about Integrated Supply Chain Scheduling (ISCS) models to help
identify deficiencies in this area. For this purpose, it is thought that this study will
contribute in terms of guiding researchers working in this field. In this study,
existing literature on ISCS problems are reviewed and summarized by introducing
the new classification scheme. The studies were categorized by considering the
features such as the number of customers (single or multiple), product lifespan
(limited or unlimited), order sizes (equal or general), vehicle characteristics
(limited/sufficient and homogeneous/heterogeneous), machine configurations and
number of objective function (single or multi objective). In addition, properties of
mathematical models applied for problems and solution approaches are also
discussed.Bütünleşik Tedarik Zinciri Çizelgeleme (BTZÇ) üzerine yapılan araştırmalar
nispeten yenidir ve bu konu üzerine yapılan çalışma sayısı artmaktadır. Bu çalışma,
bu alandaki eksiklikleri tespit etmeye yardımcı olmak için BTZÇ modelleri hakkında
kapsamlı bir literatür araştırması sunmaktadır. Bu amaçla, bu çalışmanın bu alanda
çalışan araştırmacılara rehberlik etmesi açısından katkı sağlayacağı
düşünülmektedir. Bu çalışmada, BTZÇ problemleri üzerine mevcut literatür gözden
geçirilmiş ve yeni sınıflandırma şeması tanıtılarak çalışmalar özetlenmiştir.
Çalışmalar; tek veya çoklu müşteri sayısı, sipariş büyüklüğü tipi (eşit veya genel),
ürün ömrü (sınırlı veya sınırsız), araç karakteristikleri (sınırlı/yeterli ve
homojen/heterojen), makine konfigürasyonları ve amaç fonksiyonu sayısı (tek veya
çok amaçlı) gibi özellikler dikkate alınarak kategorize edildi. Ayrıca problemler için
uygulanan matematiksel modellerin özellikleri ve çözüm yaklaşımları da
tartışılmıştır
Scheduling Single-Machine Problem Oriented by Just-In-Time Principles - A Case Study
Developments in advanced autonomous production resources have increased the interest in the Single-Machine Scheduling Problem (SMSP). Until now, researchers used SMSP with little to no practical application in industry, but with the introduction of multi-purpose machines, able of executing an entire task, such as 3D Printers, replacing extensive production chains, single-machine problems are becoming a central point of interest in real-world scheduling. In this paper we study how simple, easy to implement, Just-in-Time (JIT) based, constructive heuristics, can be used to optimize customer and enterprise oriented performance measures. Customer oriented performance measures are mainly related to the accomplishment of due dates while enterprise-oriented ones typically consider other time-oriented measures.The authors wish to acknowledge the support of the Fundação para a Ciência e Tecnologia (FCT), Portugal, through the grant “Projeto Estratégico – UI 252 – 2011–2012” reference PEst-OE/EME/UI0252/2011 and FCOMP-01-0124FEDER-PEst-OE/EEI/UI0760/2014info:eu-repo/semantics/publishedVersio
A survey of scheduling problems with setup times or costs
Author name used in this publication: C. T. NgAuthor name used in this publication: T. C. E. Cheng2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
A single-machine scheduling problem with multiple unavailability constraints: A mathematical model and an enhanced variable neighborhood search approach
AbstractThis research focuses on a scheduling problem with multiple unavailability periods and distinct due dates. The objective is to minimize the sum of maximum earliness and tardiness of jobs. In order to optimize the problem exactly a mathematical model is proposed. However due to computational difficulties for large instances of the considered problem a modified variable neighborhood search (VNS) is developed. In basic VNS, the searching process to achieve to global optimum or near global optimum solution is totally random, and it is known as one of the weaknesses of this algorithm. To tackle this weakness, a VNS algorithm is combined with a knowledge module. In the proposed VNS, knowledge module extracts the knowledge of good solution and save them in memory and feed it back to the algorithm during the search process. Computational results show that the proposed algorithm is efficient and effective
A survey of variants and extensions of the resource-constrained project scheduling problem
The resource-constrained project scheduling problem (RCPSP) consists of activities that must be scheduled subject to precedence and resource constraints such that the makespan is minimized. It has become a well-known standard problem in the context of project scheduling which has attracted numerous researchers who developed both exact and heuristic scheduling procedures. However, it is a rather basic model with assumptions that are too restrictive for many practical applications. Consequently, various extensions of the basic RCPSP have been developed. This paper gives an overview over these extensions. The extensions are classified according to the structure of the RCPSP. We summarize generalizations of the activity concept, of the precedence relations and of the resource constraints. Alternative objectives and approaches for scheduling multiple projects are discussed as well. In addition to popular variants and extensions such as multiple modes, minimal and maximal time lags, and net present value-based objectives, the paper also provides a survey of many less known concepts. --project scheduling,modeling,resource constraints,temporal constraints,networks
Production Scheduling Requirements to Smart Manufacturing
The production scheduling has attracted a lot of researchers for many years, however most of the approaches are not targeted to deal with real manufacturing environments, and those that are, are very particular for the case study. It is crucial to consider important features related with the factories, such as products and machines characteristics and unexpected disturbances, but also information such as when the parts arrive to the factory and when should be delivered. So, the purpose of this paper is to identify some important characteristics that have been considered independently in a lot of studies and that should be considered together to develop a generic scheduling framework to be used in a real manufacturing environment.authorsversionpublishe
A new hybrid meta-heuristic algorithm for solving single machine scheduling problems
A dissertation submitted in partial ful lment of the
degree of Master of Science in Engineering (Electrical) (50/50)
in the
Faculty of Engineering and the Built Environment
Department of Electrical and Information Engineering
May 2017Numerous applications in a wide variety of elds has resulted in a rich history of research
into optimisation for scheduling. Although it is a fundamental form of the problem, the
single machine scheduling problem with two or more objectives is known to be NP-hard.
For this reason we consider the single machine problem a good test bed for solution
algorithms. While there is a plethora of research into various aspects of scheduling
problems, little has been done in evaluating the performance of the Simulated Annealing
algorithm for the fundamental problem, or using it in combination with other techniques.
Speci cally, this has not been done for minimising total weighted earliness and tardiness,
which is the optimisation objective of this work.
If we consider a mere ten jobs for scheduling, this results in over 3.6 million possible
solution schedules. It is thus of de nite practical necessity to reduce the search space in
order to nd an optimal or acceptable suboptimal solution in a shorter time, especially
when scaling up the problem size. This is of particular importance in the application
area of packet scheduling in wireless communications networks where the tolerance for
computational delays is very low. The main contribution of this work is to investigate
the hypothesis that inserting a step of pre-sampling by Markov Chain Monte Carlo
methods before running the Simulated Annealing algorithm on the pruned search space
can result in overall reduced running times.
The search space is divided into a number of sections and Metropolis-Hastings Markov
Chain Monte Carlo is performed over the sections in order to reduce the search space for
Simulated Annealing by a factor of 20 to 100. Trade-o s are found between the run time
and number of sections of the pre-sampling algorithm, and the run time of Simulated
Annealing for minimising the percentage deviation of the nal result from the optimal
solution cost. Algorithm performance is determined both by computational complexity
and the quality of the solution (i.e. the percentage deviation from the optimal). We
nd that the running time can be reduced by a factor of 4.5 to ensure a 2% deviation
from the optimal, as compared to the basic Simulated Annealing algorithm on the full
search space. More importantly, we are able to reduce the complexity of nding the
optimal from O(n:n!) for a complete search to O(nNS) for Simulated Annealing to
O(n(NMr +NS)+m) for the input variables n jobs, NS SA iterations, NM Metropolis-
Hastings iterations, r inner samples and m sections.MT 201
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