In this paper, we consider the problem of partner selection in a virtual organisation (VO); specifically, we develop mixed integer linear programming (MILP) models to support the configuration of VOs in a virtual organisation breeding environment (VBE). Apart from the basic model which focuses on the minimisation of total fixed and variable costs we present extensions which capture transportati...

In this paper, we consider the problem of partner selection in a virtual organisation (VO); specifically, we develop mixed integer linear programming (MILP) models to support the configuration of VOs in a virtual organisation breeding environment (VBE). Apart from the basic model which focuses on the minimisation of total fixed and variable costs we present extensions that capture transportatio...

Recent experiments by Fischetti and Lodi show that the first Chvátal closure of a pure integer linear program (ILP) often gives a surprisingly tight approximation of the integer hull. They optimize over the first Chvátal closure by modeling the Chvátal–Gomory (CG) separation problem as a mixed integer linear program (MILP) which is then solved by a generalGérard Cornuéjols was supported in part...

SelfSplit is a simple mechanism to convert a sequential tree-search code into a parallel one. In this paradigm, tree-search is distributed among a set of workers, each of which is able to autonomously determine—without any communication with the other workers—the job parts it has to process. SelfSplit already proved quite effective in parallelizing Constraint Programming solvers. In the present...

We present a method, based on formulation symmetry, for generating Mixed-Integer Linear Programming (MILP) relaxations with fewer variables than the original symmetric MILP. Our technique also extends to convex MINLP, and some nonconvex MINLP with a special structure. We showcase the effectiveness of our relaxation when embedded in a decomposition method applied to two important applications (m...

This paper addresses the problem of developing an optimisation model to aid the operational decision-making process in pipeline systems. The model is applied on a real world pipeline oil distribution scenario, which connects an inland refinery to a harbour, conveying multiple types of commodities. The optimisation model was developed based on mixed integer linear programming (MILP) with uniform...

This paper considers the multi level uncapacitated facility location problem (MLUFLP). A new mixed integer linear programming (MILP) formulation is presented and validity of this formulation is given. Experimental results are performed on instances known from literature. The results achieved by CPLEX and Gurobi solvers, based on the proposed MILP formulation, are compared to the results obtaine...

Production optimization of gas-lifted oil fields under facility, routing, and pressure constraints has attracted the attention of researchers and practitioners for its scientific challenges and economic impact. The available methods fall into one of two categories: nonlinear or piecewise-linear approaches. The nonlinear methods optimize simulation models directly or use surrogates obtained by c...

The problem of data reconciliation and the detection and identification of gross errors, such as measurement bias, are closely related and permits a solution within a mixed integer optimization framework. A mixed-integer linear programming (MILP) approach has been previously investigated by Soderstrom et al. (2001), where the process model was described by a set of linear equations. This paper ...