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Project Planning With Alternative Technologies In Uncertain Environments, Stefan Creemers, Bert De Reyck, Roel Leus
Project Planning With Alternative Technologies In Uncertain Environments, Stefan Creemers, Bert De Reyck, Roel Leus
Research Collection Lee Kong Chian School Of Business
We investigate project scheduling with stochastic activity durations to maximize the expected net present value. Individual activities also carry a risk of failure, which can cause the overall project to fail. In the project planning literature, such technological uncertainty is typically ignored and project plans are developed only for scenarios in which the project succeeds. To mitigate the risk that an activity’s failure jeopardizes the entire project, more than one alternative may exist for reaching the project’s objectives. We propose a model that incorporates both the risk of activity failure and the possible pursuit of alternative technologies. We find optimal …
A Hybrid Scatter Search For The Discrete Time/Resource Trade-Off Problem In Project Scheduling, Mohammad Ranbar, Bert De Reyck, Fereydoon Kianfar
A Hybrid Scatter Search For The Discrete Time/Resource Trade-Off Problem In Project Scheduling, Mohammad Ranbar, Bert De Reyck, Fereydoon Kianfar
Research Collection Lee Kong Chian School Of Business
We develop a heuristic procedure for solving the discrete time/resource trade-off problem in the field of project scheduling. In this problem, a project contains activities interrelated by finish-start-type precedence constraints with a time lag of zero, which require one or more constrained renewable resources. Each activity has a specified work content and can be performed in different modes, i.e. with different durations and resource requirements, as long as the required work content is met. The objective is to schedule each activity in one of its modes in order to minimize the project makespan. We use a scatter search algorithm to …
A Hybrid Scatter Search/Electromagnetism Meta-Heuristic For Project Scheduling, Dieter Debels, Bert De Reyck, Roel Leus, Mario Vanhoucke
A Hybrid Scatter Search/Electromagnetism Meta-Heuristic For Project Scheduling, Dieter Debels, Bert De Reyck, Roel Leus, Mario Vanhoucke
Research Collection Lee Kong Chian School Of Business
In the last few decades, several effective algorithms for solving the resource-constrained project scheduling problem have been proposed. However, the challenging nature of this problem, summarised in its strongly NP-hard status, restricts the effectiveness of exact optimisation to relatively small instances. In this paper, we present a new meta-heuristic for this problem, able to provide near-optimal heuristic solutions for relatively large instances. The procedure combines elements from scatter search, a generic population-based evolutionary search method, and from a recently introduced heuristic method for the optimisation of unconstrained continuous functions based on an analogy with electromagnetism theory. We present computational …
A Note On The Paper “Resource-Constrained Project Scheduling: Notation, Classification, Models And Methods” By Brucker Et Al., Willy Herroelen, Erik Demeulemeester, Bert De Reyck
A Note On The Paper “Resource-Constrained Project Scheduling: Notation, Classification, Models And Methods” By Brucker Et Al., Willy Herroelen, Erik Demeulemeester, Bert De Reyck
Research Collection Lee Kong Chian School Of Business
The great variety of project scheduling problems studied in the ever growing literature motivated the recent development of classification schemes. In a recent paper (European Journal of Operational Research 112 (1999) 3–41), Brucker et al. make the claim that, so far, no classification scheme exists which is compatible with what is commonly accepted in machine scheduling and introduce a new classification. In this note, we critically review major shortcomings of the suggested scheme which place heavy limitations on its potential use.
Local Search Methods For The Discrete Time/Resource Trade-Off Problem In Project Networks, Bert De Reyck, Erik Demeulemeester, Willy Herroelen
Local Search Methods For The Discrete Time/Resource Trade-Off Problem In Project Networks, Bert De Reyck, Erik Demeulemeester, Willy Herroelen
Research Collection Lee Kong Chian School Of Business
In this paper we consider the discrete time/resource trade-off problem in project networks. Given a project network consisting of nodes (activities) and arcs (technological precedence relations), in which the duration of the activities is a discrete, nonincreasing function of the amount of a single renewable resource committed to it, the discrete time/resource trade-off problem minimizes the project makespan subject to precedence constraints and a single renewable resource constraint. For each activity, a work content is specified such that all execution modes (duration/resource requirement pairs) for performing the activity are allowed as long as the product of the duration and the …