Sven Spieckermann

A sequential ordering problem in automotive paint shops

In paint shops in the automotive industry, a change of colours between two consecutive cars causes sequence-dependent set-up costs. Often, selectivity banks are used as storage and retrieval systems to create colour-oriented batches of cars before the paint application in order to reduce set-up costs. The efficient control of those selectivity banks is considered a major problem of operating paint shop systems. A branch&bound approach for the colour batching process is presented. Some computational results obtained with the approach are described. An additional focus is to outline the characteristics of parts of the colour-batching problem in selectivity banks as a sequential ordering problem.

Simulation in Produktion und Logistik

Karlsruhe (TH) soll sich vorrangig der Integration technischer, organisatorischer und personalorientierter Aspekte bei der Modellierung und Simulation von Produktionsund Logistiksystemen widmen. Damit soll aufgezeigt werden, dass Simulationsverfahren in der Lage sind, vielfaltige Aspekte des technischen Managements gleichermasen modellhaft abzubilden und auf der Basis einer multikriteriellen Zielsetzung zu bewerten. Dies hat Auswirkungen auf die Datenhaltung und die Modellierungstechnik, beruhrt aber auch Fragen der Verifikation und Validierung von Simulationsverfahren und der mit ihnen erstellten Modelle. Wie schon bei den vorangegangenen ASIM-Fachtagungen sollen Forschung, Entwicklung und industrielle Nutzung gleichermasen diskutiert werden. Es werden aktuelle Forschungsergebnisse wie auch Best-Practice-Beispiele der Simulation im betrieblichen Alltag vorgestellt. Somit erhalten Teilnehmer ohne Simulationserfahrung einen Uberblick uber Moglichkeiten und Grenzen der Simulation, wahrend erfahrene Anwender die Tagung zum Erfahrungsaustausch nutzen und neue Angebote begutachten konnen.

A new procedure model for verification and validation in production and logistics simulation

Verification & validation of simulation models and results has been strongly investigated in the context of defence applications. Significantly less substantial work can be found for applications for production and logistics, which is surprising when taking into account the massive impact that wrong or inadequate simulation results can have on strategic and investment-related decisions for large production and logistics systems. The authors have, therefore, founded an expert group for this specific topic in the year 2003, which has analysed the existing material and then developed proposals for definitions, overviews on existing V&V techniques, practical hints for the documentation of the procedural steps within a simulation study, and a specific procedure model for V&V in the context of simulation for production and logistics. The results of this working group are available as a textbook, in German. This paper summarises major results.

A case study in empty railcar distribution

Abstract Empty railcar distribution problems are considered to be at the very heart of freight traffic. Whereas mathematical models and theoretical results for corresponding network flow problems are widespread throughout the literature the respective carrying forward into real-world applications still needs to be pushed ahead. In this paper we discuss a case study performed in collaboration with a German railcar rental company. The primary objective is to provide reasonable algorithmic support for a specific empty railcar distribution problem. In this respect the main task lies in comparing a simple heuristic approach with one of the older network flow approaches.

Towards assisted input and output data analysis in manufacturing simulation: the EDASim approach

Discrete-event simulation has been established as an important methodology in various domains. In particular in the automotive industry, simulation is used to plan, control, and monitor processes including the flow of material and information. Procedure models help to perform simulation studies in a structured way and tools for data preparation or statistical analysis provide assistance in some phases of simulation studies. However, there is no comprehensive data assistance following all phases of such procedure models. In this article, a new approach combining assistance functionalities for input and output data analysis is presented. The developed tool - EDASim - focuses on supporting the user in selection, validation, and preparation of input data as well as to assist the analysis of output data. The proposed methods have been implemented and initial evaluations of the concepts have led to promising feedback from practitioners.

Simulation in manufacturing planning of buildings

Optimal planning of construction projects requires an efficient allocation of available resources. Labor, material, equipment are to be planned, coordinated and quickly adapted to varying conditions. Frequent (design) changes during the construction period, diversity of trades and the high complexity of interacting processes in building manufacturing require innovative ways to support process-influencing decisions - a tool which allows testing interventions and adjustments in the manufacturing process, including individual sub-processes with the best possible efficiency. In this context, the discrete-event simulation comes into place. A research group simulated the manufacturing process of a hotel project in all details in order to examine applicability of simulation in the construction industry and to scrutinize and adjust it according to the construction specifics. The approach taken, the challenges encountered and insights gained will be presented in this article.

An approach for increasing flexibility in green supply chains driven by simulation

Flexibility is a relevant topic in the field of green supply chains (GSC), as disturbances lead to additional transport and storage, frequently aggravated by energy-consuming air conditioning requirements. This paper discusses how simulation can support to establish flexible GSCs with specific focus on decreasing CO2 and energy consumption. For this purpose, the term flexibility is structured into categories, and methodological approaches driven by simulation in supply chains are studied. Flexibility requirements in the context of a GSC are analyzed and potential support derived for increasing this flexibility, gained by a join of simulation techniques, data models and morphological characteristics of flexibility. An approach for systematic flexibility analysis is presented on the grounds of a data mart that represents both internal and external factors influencing GSC scenarios.

A case study on simulation and emulation of a new case picking system for a us based wholesaler

This paper presents a comprehensive and long-term joint simulation project in the area of warehouse logistics. The project comprised six stages with the first three stages being part of the development and evaluation of a new storage and picking technology. This technology is a specific case picking approach and it includes process steps like storage of product pallets, automated de-palletizing, storage of product layers, the separation of product cases from layers, sequencing and palletizing of product cases. Within the second part of the project the technology was adapted to the requirements of a US-based wholesaler. The simulation activities within this second part started with classical planning simulation and covered the emulation of the real-world control software, the support of the system ramp-up, and finally the implementation of a permanent test base in order to evaluate necessary software changes. The article describes the storage and picking technology, the stages of the simulation project and the benefits of both, the technology itself and the extensive simulation application.

Qualitätssicherung lagerlogistischer Steuerungssoftware durch Simulation

prüfung des Systemdurchsatzes, d. h. ob die gewünschte Ausbringungsmenge pro Zeiteinheit abgegeben werden kann. Diese Frage wird im Rahmen der Analyse so unterschiedlicher Systeme wie Automobilrohbau oder Distributionszentren untersucht; vgl. z. B. [7,26]. Während der Konzeption eines logistischen Systems werden die weitgehend statischen Berechnungen und Zeichnungen des Planungsingenieurs durch Simulationsexperimente unterstützt, die ein Testen (und Nachweisen) der Leistungsfähigkeit dynamischer Systeme ermöglichen sowie die dynamischen Zusammenhänge anschaulich am Bildschirm aufzeigen. Seit einigen Jahren gibt es, nicht zuletzt dank der zunehmenden Möglichkeiten der zahlreichen Simulationswerkzeuge [23, 21], zusätzlich einen Trend zu sog. 1Online-Simulationa [22]. So propagiert die den Einsatz der Simulation in Deutschland beschreibende Richtlinie 3633 des Vereins Deutscher Ingenieure [24] den Einsatz von Simulation während des gesamten Lebenszyklus eines logistischen Systems: Neben der Systemplanung wird der Einsatz von Simulation auch während der Realisierung und Inbetriebnahme und zur Unterstützung des laufenden Betriebs des Systems empfohlen. In dieser Arbeit befassen wir uns mit dem Einsatz von Simulationsmodellen während der Realisierung und Inbetriebnahme groûer Lagersysteme. Ziel des beschriebenen Ansatzes ist es, die kostenintensive Einführungsphase der Software durch die durchgängige Nutzung des Simulationsmodells während der Testphase drastisch zu verkürzen. Die Kosten entstehen, da das Aufdecken und Beheben von Fehlern in der Software durch 1Experimentea an der realen Anlage sehr aufwendig ist. In Abschn. 2 wird zunächst die Entwicklung von Steuerungssoftware für Lagersysteme unter besonderer Berücksichtigung von Testverfahren vorgestellt, um darauf aufbauend Potentiale und Voraussetzungen für den Einsatz der Simulation im Rahmen

Simulationsgestützte Planung energieeffizienter Produktionssysteme

Kurzfassung Die wachsende Bedeutung der Energieeffizienz in der Produktion bedingt auch ihre adäquate Berücksichtigung in der Produktions- und Logistikplanung. Die Automobilindustrie sieht daher die Notwendigkeit, eine energetische Bewertung in die Modelle der Digitalen Fabrik zu integrieren. Der Beitrag beschreibt ein mögliches Integrationskonzept, stellt die implementierte technische Lösung vor, diskutiert Einsatzmöglichkeiten sowie ein Anwendungsbeispiel.