Industrial linear optimization problems solved by constraint logic programming

In this article we try to illustrate that constraint logic programming (CLP) systems allow easy expression and solution of constrained decision problems. In order to do so, this paper proposes CLP solutions for two industrial linear optimization problems respectively using the Prolog III and the CHIP language. The first problem, a mixed linear multicriteria selection problem, illustrates the general linear rational solver. In order to fix some integer variables a branch and bound rounding heuristic is formulated. The second problem, a linear integer multicriteria location problem, is only concerned with integer finite domain variables and is particularly adapted to the CHIP system that provides a computation domain handling such variables.