Die Entscheidung zwischen Eigenerstellung oder Fremdbezug bestimmter Erzeugnisse wird in der Betriebswirtschaftslehre traditionell anhand kostenorientierter Kriterien gefällt, die die Mehrkosten des Fremdbezugs betrachten. In diesem Beitrag wurde gezeigt, daß dieses Entscheidungskriterium...

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...

This contribution defines an instance generator for capacitated, dynamic, multi-level lot sizing problems. It provides sophisticated methods for generating systematically varied parameter level combinations automatically. This helps to perform evaluations of lot sizing methods according to a...

Where standard MLP-solvers fail to compute optimum objective function values for certain MLP-model formulations, lower bounds may be used as a point of reference for evaluating heuristics. In this paper, we compute lower bounds for the multi-level proportional lot sizing and scheduling problem...

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...

Lotsizing and scheduling comprises activities which have to be done repeatedly within MRP-systems. First, we show via a simple example the deficiencies arising within the MRP-context by neglecting the interrelationships of multi-stage systems. Second, we propose a new model for multi-item,...

This contribution presents two heuristic approaches for multi-level, single-machine lot sizing and scheduling. The first one is a variant of a so-called randomized regret based heuristic which is assumed to be the fastest available method for this particular class of problems. The second...

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...