Formulating a model which summarises transportation costs, uncertainty and price, we describe how a switch to ICT procurement can impact more readily procured services rather than materials. Uncertainty represents a catch-all factor describing the dovetailing of operations between two neither...

One of the basic assumptions of the classical dynamic lot-sizing model is that theaggregate demand of a given period must be satisfied in that period. Under thisassumption, if backlogging is not allowed then the demand of a given period cannotbe delivered earlier or later than the period. If...

The problem of scheduling multiple, large scale, make-to-order assemblies is considered. Beside "classical" precedence- and resource constraints as known from resource constrained project scheduling we take spatial resource and part availability constraints into account. The objective is to...

We consider the problem of scheduling multiple, large-scale, make-to-order assemblies under resource, assembly area, and part availability constraints. Such problems typically occur in the assembly of high volume, discrete make-to-order products. Based on a list scheduling procedure which has...

The car sequencing problem is to find feasible sequences of product variants requiring specific options while taking care of sequencing constraints. First, a branching scheme and constraint propagation algorithms for the computation of feasible sequences are provided. Second, an algorithm is...

A flow line consists of a sequence of work places (or stations) through which one or more producta (or models) move one-way in order to be processed. Each model requires specific Operations which must be performed in a predefined Order. To be able to do so, the stations must be equipped with...

This paper presents a mixed-integer program for the dynamic lot sizing and scheduling problem in a multi-level, single-machine environment. It turns out that in contrast to single-level problems the integration of initial inventory is a crucial aspect if generality should not be lost. It is...

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...