Showing papers in "International Transactions in Operational Research in 1998"

TL;DR: In this paper, the authors investigated the impact of supply chain management on logistical performance indicators in food supply chains and identified the following clusters of sources of uncertainty: order forecast horizon, input data, administrative and decision processes and inherent uncertainties.

TL;DR: A newly developed Decision Support System (DSS) called SMILE (Strategic Model for Integrated Logistic Evaluations) produces forecasts of freight flows related to the Netherlands for a large number of products and modes of transport.

TL;DR: In this article, a branch-and-bound algorithm and a reduced gradient method are used to solve the problem of finding the extremum of a linear objective function at extreme points.

TL;DR: In this article, the authors investigated the impact of supply chain management on logistical performance indicators in food supply chains and found that reduction of uncertainties can improve service levels significantly, although current supply chain configurations restrict possible benefits.

TL;DR: In this paper, the authors present and implement some new ideas for fine-tuning a tabu search algorithm using statistical tests, which can be adapted and applied to other Tabu search algorithms as well.

TL;DR: In this paper, a piecewise linear structure of the cost coefficients is exploited to find the minimax regret solution to a linear program with interval objective function coefficients using an algorithm that, at each iteration, solves a linear programs to generate a candidate solution and a mixed integer program to find a corresponding maximum regret.

TL;DR: A yield management research project in SAS focuses upon passenger preferences in situations where the preferred flight, class alternative is sold out, and needs of developing SAS present origin-to-destination heuristic were identified, and alternatives for revising the class allocation models were assessed.

TL;DR: In this paper, a branch-and-bound approach was used to solve the one-dimensional cutting stock problem, where a cutting pattern is decomposed into single arc variables, which are then combined with variable generation.

TL;DR: In this paper, a two-stage distribution-planning problem is addressed, where customers are to be served with different commodities from a number of plants, through the number of intermediate distribution centres (DCs).

TL;DR: A branch and bound algorithm for solving an uncapacitated facility location problem (UFLP) with an aggregate capacity constraint is presented in this paper, which is an extension of a procedure used by Christofides and Beasley (A tree search algorithm for the p-median problem).

TL;DR: A tactical decision model is presented that improves the effectiveness of the operations of a distribution center for vegetables and fruits by determining an assignment plan, based on historical data, that is used at the operational level for storage advice.

TL;DR: In this paper, the relationship between agile manufacturing and management of variability is discussed and the effects of variability of the structure of the production system, and also the processing time variability on the performance of a manufacturing system are studied by utilizing a simple model of a synchronous production line with identical stations and random processing times.

TL;DR: It is shown that the longest processing time and the shortest processing time orders are optimal with respect to both criteria in a two-machine ordered flowshop when the first or the second machine, respectively, suffers stochastic breakdowns.

TL;DR: In this article, existing fixed-point models for stochastic equilibrium traffic assignment to transportation networks are extended to deal with the value of time distributed among users, which is relevant when transporation demand management measures affecting travelling monetary costs are to be evaluated.

TL;DR: A model where turn delays have been included in the solution algorithm of Stochastic User Equilibrium (SUE) traffic assignment, where the links cost-functions of the links are traffic dependent and convergence can be shown probable for model data representing realistic road-networks.

TL;DR: This paper formulate several fixed charge network design models, capacitated or uncapacitated, directed or undirected, possibly with staircase costs, and survivability requirements, based on Lagrangean relaxation, subgradient optimization and primal heuristics, which together form a LagrangeAn heuristic.

TL;DR: A modified Hooke–Jeeves search algorithm that exploits the two design rules that were extracted for the optimal buffer allocation in balanced production lines to give an initial buffer allocation close to the optimal one.

TL;DR: This study proposes a method to find an optimal process to expand one's competence set through an expansion order and by a directed graph, the optimal path of expansion at each stage can be found by a proposed model.

TL;DR: In this paper, the authors present an approach based on a niched pareto evolutionary algorithm which does not rely on weights or distances to a target solution, allowing several solutions to be provided, so that a choice is offered to the decision maker, according to his/her particular constraints.

TL;DR: In this article, the authors use the example of an agro-food company seeking new organisational forms while its markets were becoming increasingly deregulated, the design of material planning systems as the main managerial driver for reforming the organisation is identified.

TL;DR: An algorithm for optimal control of a gas network with any configuration based upon hierarchical control and decomposition of the network is described, using the ‘good coordination’ method to find the overall optimum.

TL;DR: In this paper, the authors report on the development of a procedure that can automate the task of adding data for intersection delay modelling to an existing network, which requires a GIS-based network with link attributes as input data.

TL;DR: An efficient two-stage algorithm has been developed to solve a large-scale multiobjective scheduling problem in steel sheets production that enables synchronized scheduling for a multistage manufacturing process as well as to reduce the number of combinations.

TL;DR: Computational results show that a reduction of 200% or more in terms of number of iterations and function/gradient evaluations respectively could be achieved by the new parallel algorithm over a wide range of 63 test problems.

TL;DR: Two Operations Research models for optimization of ventilation control device locations and sizes in two different mine ventilation systems are presented: a controlled flow ventilation system, for which a mixed integer programming model is introduced, and a semi-controlled flow ventilationSystem, which is formulated as a nonlinear, nonconvex model.

TL;DR: In this paper, the authors considered a bicriteria model for locating a semi-desirable facility on the plane, where one criterion is that of minimizing the sum of weighted distances between customers and facility, where distances are given by an arbitrary norm.

TL;DR: In this paper, the authors present a new way of indermediation in the transport and logistic, and discuss how the role of these concerns would be modified by Internet/Intranet.

TL;DR: An instrument that has been developed to assess the quality of a simulation study in which the customers are highly involved, known as SimQual, is described, founded on the principles of quality measurement, and in particular service quality.

TL;DR: In this paper, the current logistic performance of the Dutch catering chain was analyzed and performance indicators and logistic scenarios were formulated, and two most promising alternative scenarios for all supply chain partners were tested in a real-life situation.

TL;DR: In this article, the authors describe the modelling approach for the sales of gasoline in service stations located in a Portuguese metropolitan area and develop models for planning purposes in order to assess potential sales of new sites.