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38
A Survey of Automated Timetabling
, 1999
"... The timetabling problem consists in scheduling a sequence of lectures between teachers and students in a prefixed period of time (typically a week), satisfying a set of constraints of various types. A large number of variants of the timetabling problem have been proposed in the literature, which d ..."
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Cited by 196 (16 self)
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The timetabling problem consists in scheduling a sequence of lectures between teachers and students in a prefixed period of time (typically a week), satisfying a set of constraints of various types. A large number of variants of the timetabling problem have been proposed in the literature, which differ from each other based on the type of institution involved (university or school) and the type of constraints. This problem, that has been traditionally considered in the operational research field, has recently been tackled with techniques belonging also to Artificial Intelligence (e.g., genetic algorithms, tabu search, and constraint satisfaction). In this paper, we survey the various formulations of the problem, and the techniques and algorithms used for its solution.
A Tutorial for Competent Memetic Algorithms: Model, Taxonomy, and Design Issues
 IEEE Transactions on Evolutionary Computation
, 2005
"... We recommend you cite the published version. ..."
A MultiStage Evolutionary Algorithm for the Timetable Problem
, 1998
"... It is well known that timetabling problems can be particularly difficult to solve, especially when dealing with particularly large instances. Finding near optimal results can prove to be extremely difficult, even when using advanced search methods such as evolutionary algorithms (EAs). In this paper ..."
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Cited by 97 (31 self)
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It is well known that timetabling problems can be particularly difficult to solve, especially when dealing with particularly large instances. Finding near optimal results can prove to be extremely difficult, even when using advanced search methods such as evolutionary algorithms (EAs). In this paper we present a method of decomposing larger problems into smaller components, each of which is of a size that the EA can effectively handle. We will show various experimental results using this method to prove that not only can the execution time be considerably reduced but also that the presented method can actually improve the quality of produced solutions.
A TimePredefined Local Search Approach to Exam Timetabling Problems
, 2001
"... ... This paper is devoted to the investigation of that question. We present two variants of local search algorithms where the search time can be set as an input parameter. These two approaches are: a timepredefined variant of simulated annealing and a specially designed local search that we have ca ..."
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Cited by 85 (44 self)
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... This paper is devoted to the investigation of that question. We present two variants of local search algorithms where the search time can be set as an input parameter. These two approaches are: a timepredefined variant of simulated annealing and a specially designed local search that we have called the "degraded ceiling" method. We present a comprehensive series of experiments, which show that these approaches significantly outperform the previous best results (in terms of solution quality) on the most popular benchmark exam timetabling problems. Of course there is a price to pay for such better results: increased execution time. We discuss the impact of this tradeoff between quality and execution time. In particular we discuss issues involving the proper estimation of the algorithm's execution time and assessing its importance
Solving Examination Timetabling Problems through Adaption of Heuristic Orderings
, 2003
"... Heuristic ordering based methods, very similar to those used for graph colouring problems, have long been applied successfully to the examination timetabling problem. Despite the success of these methods on real life problems, even with limited computing resources, the approach has the fundamenta ..."
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Cited by 64 (26 self)
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Heuristic ordering based methods, very similar to those used for graph colouring problems, have long been applied successfully to the examination timetabling problem. Despite the success of these methods on real life problems, even with limited computing resources, the approach has the fundamental flaw that it is only as effective as the heuristic that is used. One of the motivations of this paper is to attempt to develop approaches that can operate at a higher level of generality and that can adapt heuristics to suit the particular problem instance in hand.
Evolution of Constraint Satisfaction Strategies in Examination Timetabling
 Proceedings of the Genetic and Evolutionary Computation Conference (GECCO99
"... This paper describes an investigation of solving Examination Timetabling Problems (ETTPs) with Genetic Algorithms (GAs) using a nondirect chromosome representation based on evolving the configuration of Constraint Satisfaction methods. There are two aims. The first is to circumvent the problems pos ..."
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Cited by 44 (2 self)
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This paper describes an investigation of solving Examination Timetabling Problems (ETTPs) with Genetic Algorithms (GAs) using a nondirect chromosome representation based on evolving the configuration of Constraint Satisfaction methods. There are two aims. The first is to circumvent the problems posed by a direct chromosome representation for the ETTP that consists of an array of events in which each value represents the timeslot which the corresponding event is assigned to. The second is to show that the adaptation of particular features in both the instance of the problem to be solved and the strategies used to solve it provides encouraging results for real ETTPs. There is much scope for investigating such approaches further, not only for the ETTP, but also for other related scheduling problems.
Improving Evolutionary Timetabling with Delta Evaluation and Directed Mutation
 Parallel Problemsolving from Nature  PPSN III, LNCS
, 1994
"... Researchers are turning more and more to evolutionary algorithms (EAs) as a flexible and effective technique for addressing timetabling problems in their institutions. We present a class of specialised mutation operators for use in conjunction with the commonly employed penaltyfunction based EA appr ..."
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Cited by 29 (4 self)
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Researchers are turning more and more to evolutionary algorithms (EAs) as a flexible and effective technique for addressing timetabling problems in their institutions. We present a class of specialised mutation operators for use in conjunction with the commonly employed penaltyfunction based EA approach to timetabling which shows significant improvement in performance over a range of real and realistic problems. We also discuss the use of delta evaluation, an obvious and recommended technique which speeds up the implementation of the approach, and leads to a more pertinent measure of speed than the commonly used `number of evaluations'. A suite of realistically difficult benchmark timetabling problems is described and made available for use in comparative research.
A Genetic Algorithm Solving a Weekly CourseTimetabling Problem
, 1995
"... In this paper we describe a heavily constrained university timetabling problem, and our genetic algorithm based approach to solve it. A problemspecific chromosome representation and knowledgeaugmented genetic operators have been developed; these operators `intelligently' avoid building il ..."
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Cited by 22 (0 self)
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In this paper we describe a heavily constrained university timetabling problem, and our genetic algorithm based approach to solve it. A problemspecific chromosome representation and knowledgeaugmented genetic operators have been developed; these operators `intelligently' avoid building illegal timetables. The prototype timetabling system which is presented has been implemented in C and PROLOG, and includes an interactive graphical user interface. Tests with real data from our university were performed and yield promising results.
Experiments on Networks of Employee Timetabling Problems
 In Pract. Theo. Autom. Timetab. II, volume LNCS 1408
, 1997
"... Constraint networks (CN) that represent employee timetabling problems (ETP) are described and a testbed of random ETP CNs is designed. The natural representation of ETPs as CNs has variables representing working shifts and values representing employees that are assigned to workshifts. In this repre ..."
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Cited by 22 (8 self)
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Constraint networks (CN) that represent employee timetabling problems (ETP) are described and a testbed of random ETP CNs is designed. The natural representation of ETPs as CNs has variables representing working shifts and values representing employees that are assigned to workshifts. In this representation, ETPs have binary constraints of nonequality (mutual exclusion), the networks are non uniform, and variables have different domains of values. There is also a typical family of nonbinary constraints that represent finite capacity limits. The random testbed of ETPs includes all of the above features and is solved by standard constraint processing techniques, such as forward checking (FC) and conflict directed backjumping (CBJ). The set of ETP CNs is characterized by the average size of domains, together with the usual parameters of CNs (i.e. the density and tightness of constraints p 1 ; p 2 ). One major result is that the ETPs exhibit a strong change in difficulty (as measured by...
Timetabling the Classes of an Entire University with an Evolutionary Algorithm
 V, Springer, LNCS
, 1998
"... . This paper describes extensions to an evolutionary algorithm that timetables classes for an entire University. A new method of dealing with multiobjectives is described along with a user interface designed for it. New results are given concerning repair of poor recombination choices during loc ..."
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Cited by 21 (3 self)
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. This paper describes extensions to an evolutionary algorithm that timetables classes for an entire University. A new method of dealing with multiobjectives is described along with a user interface designed for it. New results are given concerning repair of poor recombination choices during local search. New methods are described and evaluated that allow timetables to be produced which have minimal changes compared to a full or partial reference timetable. The paper concludes with a discussion of scaleup issues, and gives some initial results that are very encouraging. 1. Introduction Napier University uses a timetable that was produced by an evolutionary algorithm incorporating a local search. The system timetables 100% of classes and optimises them according to twelve competing objectives. Timetabling the classes of a University involves finding timeslots for the events such that each event can have the resources (rooms, students, and lecturers) that it requires, and so ...