Complexity proofs often restrict themselves to stating that the problem at hand is a generalization of some other intractable problem, This proof technique relies on the widely accepted assumptions that complexity results hold regardless of the model formulation used to represent the problem and...

NP-completeness and other complexity proofs often merely State that the problem at hand is a generalization of some other intractable problem. This proof technique relies on the widely accepted assumption that complexity results hold regardless of the model formulation used to represent the...

This paper deals with lot sizing and scheduling for a single-stage production System where setup costs and times are sequence dependent. A large bücket mixed integer programming (MIP) model is formulated which considers only efficient sequences. A tailor-made enumeration method of the...

A batch sequencing model with sequence-dependent setup-times and -costs is used to compare modelling and solving with two different general solvers. "Conceptual models" are implemented in the constraint propagation / logic programming language CHARME and solved with the PROLOG inference engine....

This contribution deals with dynamic, capacitated, multi-level lot sizing and scheduling. The basic assumption is that for each item there is exactly one machine that this item can be manufactured on but no two items share a common machine. Finding an optimal solution with a greedy algorithm...