On On A nd nd T he in he A ABSTRACT gen This thesis concerns the integration of agent effects of different types of governmental taxes, T T eg technology and mathematical optimization for and synchronization of timetables. Moreover, we T e On The inTegratiOn Of OpTimizatiOn And rat improved decision support within the domain provide an analysis of existing MABS applica- C of analysis and planning of production and trans- tions with respect to a number of criteria. Also, hn AgenT TeChnOlOgy for tranSportatiOn i O portation. These two approaches have often been we present a framework containing a number of O n n l And productiOn plAnning used separately in this domain but the research abstract roles, responsibilities, and interactions, O O gy f gy concerning how to combine them is very limited. which can be used to simplify the process of de- f The studied domain is considered to be com- veloping MABS models. O p or plex due to the fact that many decision makers, Second, we present an approach for efficient T imiz which influence each other, often are involved in planning and execution of intermodal transports. tra the decision making process. Moreover, problems The approach provides agent-based support for at n in the domain are typically large and combinato- key tasks, such as, finding the optimal sequence of i S O p rial, which makes them more difficult to solve. transport services (potentially provided by diffe- n ortat We argue that the integration of agent-based rent transport operators) for a particular goods Johan Holmgren approaches and mathematical optimization has transport, and monitoring the execution of trans- i a high potential to improve analysis and plan- ports. We analyzed the requirements of such an O ning of production and transportation. In order approach and described a multi-agent system ar- n to support this hypothesis, we have developed chitecture meeting these requirements. A nd p nd and analyzed three different approaches to the Finally, an optimization model for a real world integration of agent technology and mathemati- integrated production, inventory, and routing pro- ro cal optimization. blem was developed. For solving and analyzing the First, we present a Multi-Agent-Based Simu- problem, we developed an agent-based solution du lation (MABS) model called TAPAS for simula- method based on the principles of Dantzig-Wolfe ct i tion of decision-making and physical activities decomposition. The purpose was to improve re- O in supply chains. By using agent technology and source utilization and to analyze the potential ef- pl n optimization, we were able to simulate the deci- fects of introducing VMI (Vendor Managed Inven- sion-making of the involved actors as well as the tory). In a case study, we conducted simulation A nning interaction between them, which is difficult using experiments, which indicated that an increased traditional simulation techniques. In simulation number of VMI customers may give a significant experiments, TAPAS has been used to study the reduction of the total cost in the system. Johan Holmgren Johan Blekinge Institute of Technology Doctoral Dissertation Series No. 2010:09 2010:09 ISSN 1653-2090 School of Computing 2010:09 ISBN: 978-91-7295-189-1 On the Integration of Optimization and Agent Technology for Transportation and Production Planning Johan Holmgren Blekinge Institute of Technology Doctoral Dissertation Series No 2010:09 On the Integration of Optimization and Agent Technology for Transportation and Production Planning Johan Holmgren School of Computing Blekinge Institute of Technology SWEDEN © 2010 Johan Holmgren School of Computing Publisher: Blekinge Institute of Technology Printed by Printfabriken, Karlskrona, Sweden 2010 ISBN: 978-91-7295-189-1 Blekinge Institute of Technology Doctoral Dissertation Series ISSN 1653-2090 urn:nbn:se:bth-00474 Abstract This thesis concerns the integration of agent technology and mathematical optimization for improved decision support within the domain of analysis and planning of produc- tion and transportation. These two approaches have often been used separately in this domain but the research concerning how to combine them is very limited. The stud- ied domain is considered to be complex due to the fact that many decision makers, which influence each other, often are involved in the decision making process. More- over, problems in the domain are typically large and combinatorial, which makes them more difficult to solve. We argue that the integration of agent-based approaches and mathematical optimization has a high potential to improve analysis and planning of production and transportation. In order to support this hypothesis, we have developed and analyzed three different approaches to the integration of agent technology and mathematical optimization. First, we present a Multi-Agent-Based Simulation (MABS) model called TAPAS for simulation of decision-making and physical activities in supply chains. By using agent technology and optimization, we were able to simulate the decision-making of the involved actors as well as the interaction between them, which is difficult using traditional simulation techniques. In simulation experiments, TAPAS has been used to study the effects of different types of governmental taxes, and synchronization of timetables. Moreover, we provide an analysis of existing MABS applications with respect to a number of criteria. Also, we present a framework containing a number of abstract roles, responsibilities, and interactions, which can be used to simplify the process of developing MABS models. Second, we present an approach for efficient planning and execution of intermodal transports. The approach provides agent-based support for key tasks, such as, finding the optimal sequence of transport services (potentially provided by different transport operators) for a particular goods transport, and monitoring the execution of transports. We analyzed the requirements of such an approach and described a multi-agent system architecture meeting these requirements. Finally, an optimization model for a real world integrated production, inventory, and routing problem was developed. For solving and analyzing the problem, we devel- oped an agent-based solution method based on the principles of Dantzig-Wolfe decom- i position. The purpose was to improve resource utilization and to analyze the potential effects of introducing VMI (Vendor Managed Inventory). In a case study, we conducted simulation experiments, which indicated that an increased number of VMI customers may give a significant reduction of the total cost in the system. ii Acknowledgements It is my great privilege to get this opportunity to thank some of the people who have helped and supported me throughout the course of writing this thesis. The municipality of Karlshamn has financially supported the research in this thesis. Moreover, the “Integrated Production and Transportation Planning within Food Indus- try” project was financed by the Swedish Knowledge Foundation (KK-stiftelsen), the “Effects of Governmental Control Policies on Transportation Chains: A Micro-Level Study” project was financed by the Swedish Agency for Innovation Systems (VIN- NOVA), and the “EastWest Transport Corridor” and “Management Framework for In- telligent Intermodal Transport (FREIGHTWISE)” projects were financed by the EU 6th Framework Programme. I would like to thank the funders of my research, as well as the project partners, in particular AarhusKarlshamn and FoodTankers, for generously sharing time, information and knowledge. I would like to express my sincere gratitude to my supervisors, Professor Paul Davidsson and Associate Professor Jan Persson, for their patience and for sharing their valuable time and knowledge. Without their support and encouragement it would have never been possible for me to complete this thesis. I am also very grateful to my friend and colleague Dr. Linda Ramstedt for her collaboration and support, and to Associate Professor Fredrik Persson for his valuable comments and suggestions during the de- fense of my licentiate thesis. The support from my friends and colleagues in the DISL research group is also appreciated. In particular I want to thank my colleague and friend Marie Persson for her invaluable and positive support, and most of all for being a good friend. I am also grateful to my family, Gertrud, Thommy, Charlotta and Andreas. Thank you for always supporting and helping me in any ways you possible could. I would also like to express my gratitude to my friends for contributing with fun times and happy memories throughout the years. Thank you for still being there for me even though I have not been around much for some time. In particular, I would like to thank Çigdem for being a truly good friend. Thank you for always being understanding, supporting and inspiring to spend time with. Karlskrona, October 2010 Johan Holmgren iii iv Preface The thesis includes the following papers: Paper I Davidsson, P., Holmgren, J., Kyhlbäck, H., Mengistu, D., & Persson, M. (2007). Applications of multi agent based simulation. In Lecture Notes in Computer Science: Vol. 4442. Multi-Agent-Based Simulation VII (pp. 15-27). Springer. Paper II Holmgren, J., Davidsson, P., Persson, J. A., & Ramstedt, L. (2010). TAPAS: A multi-agent-based model for simulation of supply chains. (Submitted for pub- lication). Paper III Holmgren, J., Ramstedt, L., Davidsson, P., & Persson, J. A. (2010). Multi- agent-based simulation for analyzing production and transportation measures: A case