In this paper we present a polynomial time dynamic programming algorithm for solving a scheduling problem with a (total) weighted completion time objective function where the weights are activity- and time-dependent. We highlight application areas for this type of problem to underscore the...

This contribution presents an efficient solution method for solving the major short-term planning problems which occur, if lot production has to be managed. In our focus are the two most important aspects, i.e. lot sizing and scheduling. Since both problems heavily interact, we propose an...

The resource investment problem deals with the issue of providing resources to a project such that a given deadline can be met. The objective is to make the resources available in the cheapest possible way. For each resource, expenses depend on the maximum amount required during the course of...

Gegenstand der vorliegenden Arbeit sind zwei praktisch und theoretisch bedeutsame Probleme, die bei just-in-time orientierter Variantenfließfertigung auftreten. Ein Problem besteht darin, den Teilebedarf in der Endmontage so konstant wie möglich zu halten ("Level Scheduling Problem"). Das...

Resource-constrained project scheduling under a net present value objective attracts growing interest. Because this is an NP-hard problem, it is unlikely that optimum solutions can be computed for large instances. Thus, heuristics have become a popular research field. Up to now, however, tight...

In project management, the project duration can often be compressed by accelerating some of its activities at an additional expense. This is the so-called time-cost tradeoff problem which has been extensively studied in the past. However, the discrete version of the problem which is of great...

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...

This paper deals with proportional lot sizing and scheduling (PLSP) and gives some insights into the properties of this problem. Such insights may be useful for developing heuristic and/or exact solution procedures. The emphasis of this paper is on the multi-level, multi-machine case. We provide...

This contribution generalizes the work of Drexl and Haase about the so-called proportional lot sizing and scheduling problem which was published in 1995. While the early paper considers single-level cases only, the paper at hand describes multi-level problems. 1t provides mixed-integer programs...

This contribution introduces a mixed-integer programming formulation for the multi-level, multi-machine proportional lot sizing and scheduling problem. It also presents a genetic algorithm to solve that problem. The efficiency of that algorithm is due to an encoding of solutions which uses a...