Thesis Topics

The Department of Logisitics is currently expressly not offering any more thesis topics except the ones listed below. If you are interested, please read the hints on how to write a thesis with the Department of Logistics and contact the supervisor mentioned below.

Bachelor or Master Topics supervised by Dr. Chankov

Do E-commerce Customers Consider Sustainability when Choosing a Last-Mile Delivery?
In the last years, the last-mile delivery started facing numerous challenges, mostly because the demand for E-commerce has risen drastically and customers’ expectations from the last-mile delivery have increased in an unsustainable way. One main reason for this unsustainable behaviour is that E-commerce customers are currently choosing between different delivery options only based on information related to their associated time, cost and location. A recent study has developed and tested a method based on making customers aware of the sustainability impact of their behaviour, by allowing them to clearly see not only the economic, but also the environmental and social impacts of the available delivery options. The obtained results clearly showed that transparent information sharing makes E-commerce customers more likely to choose a more sustainable last-mile delivery.The purpose of this thesis would be to build on the previous study and investigate the exact levels of trade-offs E-commerce customers would be willing to accept for a more sustainable last-mile delivery. For example, investigating questions such as: How much reduction of CO2 emissions would convince customers to wait one day longer for their online orders? Or how much cost savings are needed to convince customers to opt for pick-up location deliveries? The course of research can involve conducing an extensive online survey. Please contact me for recommended reading and more details on the previous study.
 Dr. Chankov
Sustainable Last Mile Delivery
You can formulate your own topic and course of research. Please contact me for relevant literature.
Dr. Chankov
Crowd Logistics: Crowdsourcing Potential for the Logistics Industry
Crowdsourcing is an increasingly used concept in a variety of fields, mainly within the scope of the sharing/collaborative economy. Crowdsourcing practices have been successfully used in other key economic fields such as: professional/personal services (e.g. Craigslist), pre-owned goods (e.g. eBay), custom products (e.g. Etsy), funding (e.g. Kickstarter), money-lending (e.g. Kiva) or transportation (e.g. Uber). While companies like Uber are already well-established in the passenger transportation area, crowd logistics (e.g. crowdsourced goods delivery, crowdshipping, or shared storage) has only recently received interest in both theory and practice. Amazon has started its initiative in Seattle September 2015 through Amazon Flex and Uber is already operating a delivery service since April 2015 named UberRUSH. Crowdsourcing could potentially be very suitable for logistics services. For example, it can help for last-mile shipments, which are becoming more and more problematic mostly due to the high growth of e-commerce. The aim of this study is to investigate crowdsourcing applications for logistics services. The course of research can involve conducting a simulation study, conducing an online survey to collect data or extensive online search to identify business models for crowd logistics. A good starting point is Rougès and Montreuil (2014).
Dr. Chankov
Crowdsourced Delivery: A Detailed Simulation Study for Last Mile Distribution
Crowdsourcing is an increasingly used concept in a variety of fields, mainly within the scope of the sharing/collaborative economy. Crowdsourcing practices have been successfully used in other key economic fields such as: accommodation (Airbnb), transportation (e.g. Uber), professional/personal services (e.g. Craigslist), pre-owned goods (e.g. eBay), custom products (e.g. Etsy), funding (e.g. Kickstarter) or money-lending (e.g. Kiva). While companies like Uber are already well-established in the passenger transportation area, crowd logistics (e.g. crowdsourced goods delivery, crowdshipping, or shared storage) has only recently received interest in both theory and practice. Amazon has started its initiative in Seattle September 2015 through Amazon Flex and Uber is already operating a delivery service since April 2015 named UberRUSH. Crowdsourced delivery is considered a possible solution to the last-mile on-demand delivery challenge. The purpose of this study is to investigate the performance of the crowdsourced last-mile delivery with regard to service level and assets utilization. An existing agent-based simulation model can be further developed in order to study the effect of parameters such as:

  • supply/demand ratio, the ratio between the number of crowd couriers delivering packages and the number of packages
  • maximum detour time accepted by crowd couriers
  • customer order density within a city
  • flow of commuters within a city
  • type of customer orders.

A good starting point is Rougès and Montreuil (2014) and Ping and Chankov (2017). Please contact me for recommended reading and more details on the model .

Dr. Chankov
Crowdsourced Delivery: Acceptability and Preference of Customers
Crowdsourced delivery is considered a possible solution to the last-mile on-demand delivery challenge. A recent study by Punel and Stathopoulos (2017) investigated the determinants of crowdshipping acceptance among senders. What factors do customers consider when choosing between different drivers to perform their crowdsourced delivery? The results suggest that in local delivery settings, senders value transparency of driver performance monitoring along with speed, while for longer shipments senders prioritize delivery conditions and driver training and experience.The purpose of this thesis is to extend these findings. You can formulate your own specific topic and course of research.
Dr. Chankov
Internal Brand Management in the Sharing Economy
Internal brand management includes the activities undertaken by an organization to ensure that the brand promise and the brand values are enacted and delivered by the organisation’s employees. In the hotel industry, for example, it is important that the hotel employees behave according to the brand values. In the sharing economy, however, the service providers are not really employed. For example, Airbnb hosts are not employed by Airbnb. Therefore, it becomes interesting to explore how their brand commitment affects the brand image of the whole company.The aim of this study is to investigate the importance of internal brand management in the sharing economy. The course of research can involve conducing an online survey to collect data or extensive data and text mining based on publicly available data (e.g. Airbnb and Uber websites). A good starting point is Burmann et al. (2009), Punjaisri and Wilson (2011) and Buil et al. (2016)
Dr. Chankov
Crowdsourcing and Sharing Economy
Crowdsourcing is an increasingly used concept in a variety of fields, mainly within the scope of the sharing/collaborative economy. Crowdsourcing practices have been successfully used in other key economic fields such as: accommodation (Airbnb), transportation (e.g. Uber), professional/personal services (e.g. Craigslist), pre-owned goods (e.g. eBay), custom products (e.g. Etsy), funding (e.g. Kickstarter) or money-lending (e.g. Kiva). While companies like Uber are already well-established in the passenger transportation area, crowd logistics (e.g. crowdsourced goods delivery, crowdshipping, or shared storage) has only recently received interest in both theory and practice. Amazon has started its initiative in Seattle September 2015 through Amazon Flex and Uber is already operating a delivery service since April 2015 named UberRUSH. Any topic for the general sharing/collaborative economy (e.g. Airbnb) is possible, you can come up with your own ideas.
 Dr. Chankov
Last-Mile Distribution: Future Trends
You can formulate your own topic and course of research. A good starting point is this DHL Report (pages 24-28).
Dr. Chankov
Omni-Channel Logistics: Case Study Analysis
You can formulate your own topic and course of research. A good starting point is this DHL Report.
Dr. Chankov
Blockchain Applications in Supply Chain Management
You can formulate your own topic and course of research. A good starting point is this article.
Dr. Chankov
Triggers and Effects of Synchronization in Supply Chains – Minimal Model Investigation
Synchronization in a broader sense means aligning a certain behavior or state over time. In the physical world, two systems can spontaneously synchronize with respect to each other even if there are only small physical interactions. Up to now it is not fully understood how synchronization affects supply chains: Does a spontaneous synchronization also occur in supply chains? If so, what triggers it and how does it influence the achievement of the logistics objectives and the robustness of the processes?
The purpose of this thesis is to study synchronization phenomena present in supply chains. Minimal models can be used to investigate the triggers and effects of those phenomena occurring in supply chains.  By applying synchronization measures to the models, the thesis will firstly examine the relation between synchronization and the supply chain’s core characteristics (e.g., design, structure, operations and control strategy, arrival times (distribution), processing time (distribution)). Secondly, it will research the link between synchronization and the supply chain performance (e.g., lateness, inventory levels) and robustness (e.g., deviations in performance due to system disturbances), thus drawing conclusions for the consequences that synchronization has on supply chains. A good starting point is:

  • [DOI] S. M. Chankov, M. Hütt, and J. Bendul, “Synchronization in manufacturing systems: quantification and relation to logistics performance,” International journal of production research, 2016.
    [Bibtex]
    @article{Chankov2016a,
    author = {Chankov, Stanislav M. and H{\"u}tt, Marc-Thorsten and Bendul, Julia},
    title = {Synchronization in manufacturing systems: quantification and relation to logistics performance},
    journal = {International Journal of Production Research},
    doi = {10.1080/00207543.2016.1165876},
    URL = {http://dx.doi.org/10.1080/00207543.2016.1165876},
    eprint = {http://dx.doi.org/10.1080/00207543.2016.1165876},
    year={2016},
    abstract = {The term 'synchronization' in manufacturing refers to the provision of the right components to the subsequent production steps at the right moment in time. It is widely assumed that synchronization is beneficial to the logistics performance of manufacturing systems. However, it has been shown that synchronization phenomena can be detrimental to systems in which they emerge. To study if synchronization phenomena also occur in and affect manufacturing systems' performance, a formal quantification and holistic understanding of the types of synchronization phenomena emerging in manufacturing are needed. This article aims to fill this research gap by developing synchronization measures for manufacturing systems, applying these measures to real-world production feedback data and utilising them to test the assumption about synchronization's beneficial effect on logistics performance. We identify two distinct synchronization types occurring in manufacturing systems, logistics and physics synchronization, and show that they are negatively correlated. Further, we show that logistics synchronization and due date performance exhibit anti-correlation and thus question the assumption that synchronization leads to higher efficiency in manufacturing systems. This article aids production managers in designing and optimising production systems, and supports further empirical research in production planning and control and production system design.},
    }
  • [DOI] S. M. Chankov, G. Malloy, and J. Bendul, “The influence of manufacturing system characteristics on the emergence of logistics synchronization: a simulation study,” in Dynamics in logistics: proceedings of the 5th international conference ldic, 2016 bremen, germany, M. Freitag, H. Kotzab, and J. Pannek, Eds., Cham: Springer International Publishing, 2016, pp. 29-40.
    [Bibtex]
    @inbook{Chankov2016b,
    author="Chankov, Stanislav M. and Malloy, Giovanni and Bendul, Julia",
    editor="Freitag, Michael and Kotzab, Herbert and Pannek, J{\"u}rgen",
    title="The Influence of Manufacturing System Characteristics on the Emergence of Logistics Synchronization: A Simulation Study",
    bookTitle="Dynamics in Logistics: Proceedings of the 5th International Conference LDIC, 2016 Bremen, Germany",
    year="2016",
    publisher="Springer International Publishing",
    address="Cham",
    pages="29--40",
    isbn="978-3-319-45117-6",
    doi="10.1007/978-3-319-45117-6_3",
    url="http://dx.doi.org/10.1007/978-3-319-45117-6_3"
    abstract="The term 'synchronization' in manufacturing refers to the provision of the right components to the subsequent production steps at the right moment in time. It is still unclear how manufacturing system characteristics impact synchronization. Thus, the purpose of this paper is to investigate the effect of manufacturing systems' characteristics on the emergence of logistics synchronization in them. We conduct a discrete-event simulation study to examine the effect of three system characteristics: (1) material flow network architecture, (2) work content variation, and (3) order arrival pattern. Our findings suggest that the material flow network architecture and the work content variation are related to logistics synchronization. Linear manufacturing systems with stable processing times such as flow shops operate at high logistics synchronization levels, while highly connected systems with high variability of processing times such as job shops exhibit lower synchronization levels."
    }
  • [DOI] M. A. Schipper, S. M. Chankov, and J. Bendul, “Synchronization emergence and its effect on performance in queueing systems,” Procedia cirp, vol. 52, pp. 90-95, 2016.
    [Bibtex]
    @article{Schipper:2016,
    title = "Synchronization Emergence and its Effect on Performance in Queueing Systems ",
    journal = "Procedia CIRP",
    volume = "52",
    number = "",
    pages = "90 -- 95",
    year = "2016",
    note = "The Sixth International Conference on Changeable, Agile, Reconfigurable and Virtual Production (CARV2016) ",
    issn = "2212-8271",
    doi = "10.1016/j.procir.2016.07.016",
    url = "http://www.sciencedirect.com/science/article/pii/S2212827116307582",
    author = "Schipper, Manuel A. and Chankov, Stanislav M. and Bendul, Julia",
    keywords = "synchronization",
    keywords = "queueing theory",
    keywords = "production system",
    keywords = "manufacturing system design ",
    abstract = "Abstract Synchronization as a dynamic process has found applications in many fields. However, it remains unclear how this phenomenon relates to manufacturing systems. The aim of this study is to investigate the conditions for emergence of synchronization and its effects on the wide spectrum of production logistics performance objectives. Using queueing theory as the underlying methodology for deductive modeling of manufacturing systems, we run computer simulations on networks of queueing systems and investigate synchronization measurements in relation to system parameters and performance indicators. Our initial findings suggest that different types of manufacturing systems display different synchronization behaviors and that periodically driven systems with deterministic arrival and service rates display higher synchronization in comparison to stochastic ones. Further, we show that intrinsic physics synchronization is correlated to capacity utilization, throughput times and WIP levels, suggesting the co-activity of operations is related to highly utilized systems, while external physics synchronization is anticorrelated to throughput times and WIP levels, suggesting that higher efficiencies emerge with workstation repetitive behavior."
    }
 Dr. Chankov

Bachelor or Master Topics supervised by Prof. Uygun

Blockchain in Supply Chain Management: Application, Opportunities and Limits Prof. Uygun
Order Prioritization in Steel Manufacturing: Quantification and Modeling of Relevant Steel Manufacturing Factors Prof. Uygun
Applying Artificial Bee Colony Optimization Method in Steel Manufacturing Prof. Uygun
Industrial Espionage & Cyber Attacks: How Severe is This Threat? An Empirical Analysis Prof. Uygun
Introduction Strategy for Lean Methods – A System Dynamics Approach Prof. Uygun
Empirical Comparison of 3D Printer Control Software Prof. Uygun
Diffusion of e-Bikes – An Agent-Based Approach Prof. Uygun
Effects of Industry 4.0 on Jobs Prof. Uygun
Understanding the Necessity of Inventory – A System Dynamics Approach Prof. Uygun
Diffusion of Vertical Axis Wind Turbines – An Agent-Based Approach Prof. Uygun

Bachelor or Master Topics supervised by Prof. Wicaksono

Industry 4.0 Commons

IC01. Readiness and willingness to change model for industry 4.0
IC02. Industry 4.0 marketplace platform
IC03. Industry 4.0 meets circular economy (self-defined topic)
IC04. Industry 4.0 meets sharing economy (self-defined topic)
IC05. Open Innovation Platform for industry 4.0
IC06. Ontologies and information systems to support Industry Commons
IC07. Industry 4.0 in agriculture – precision farming
IC08. The role of artificial intelligence, machine learning and predictive analytics in project management. How they could affect project outcomes?

Prof. Wicaksono
Supply Chain 4.0 and Manufacturing 4.0

SM01. Quality control in smart manufacturing
SM02. Reliable and accurate assembly of products containing micro parts
SM03. Harnessing the power of Artificial Intelligence for Process Industries

Prof. Wicaksono
Green Manufacturing and Circular Economy

GC01. The role of IoT and big data to green manufacturing
GC02. Materials lifecycle analysis methodology for the circular economy
GC03. Holistic energy-efficient manufacturing system management

Prof. Wicaksono
Construction 4.0 and Smart Building

CB01. Industry 4.0 in construction industry (self-defined topic)
CB02. The role of digitization in building retrofitting
CB03. Smart operation of proactive residential buildings needs – challenges in control technologies, predictive maintenance, and data supply for the customer
CB04. Construction by Digital-Twin Reconstruction.

 Prof. Wicaksono

Bachelor or Master Topics supervised by Prof. Bendul

Risk Management in Times of Industry 4.0
The student will base the theses on a profound literature review and a cross-case-study. He or she will analyze a set of 8 case studies to analyze the impact of digitalization and automation technologies on the risk situation and the resulting respectively recommended risk management measures. The student will have to make him- or herself familiar with the basics of risk management as well as with industry 4.0-technologies. Depending on the data available, it is possible to focus on a specific industry (e.g., food, machinery etc.) and/or a specific application field (e.g., transportation, maintenance, assembly etc.). The student will receive access to a database with basic information on different case studies of industry 4.0-applications including contact data to conduct expert interviews.
If you are interested, you should make yourself familiar with the basic concepts mentioned. Please prepare a 2-page proposal, in which you state why you think this topic is of practical relevance, how you would like to focus the topic, why you think this is right research project for you and your planned schedule.
More than one student can work on this topic if a specific focus is selected.
 Prof. Bendul
The Role of Digitalization for Frugal Innovation
The student will base the theses on a profound literature review and a cross-case-study. He or she will analyze a set of self-chosen 5-8 case studies to analyze the impact of digitalization on frugal innovation. The student will have to make him- or herself familiar with the basics of frugal innovation, frugal products and similar concepts as well as with different digitalization and automation technologies. Depending on the data about different cases available, it is possible to focus on a specific industry (e.g., food, machinery etc.) and/or a specific application field (e.g., products, services, business models etc.). The student may be offered access to a database different frugal products and services as the start for his or her research.
If you are interested in this thesis topic, you should make yourself familiar with the basic concepts mentioned – use the reading recommendations as a starting point. Please prepare a 2-page proposal, in which you state why you think this topic is practical relevance, how you would like to focus the topic, why you think this is right research project for you and your planned schedule.
More than one student can work on this topic if a specific focus is selected.Starting point for reading:
Rosca, E.; Arnold, M.; Bendul, J. (2016): Business models for sustainable innovation – an empirical analysis of frugal products and services. In: Journal of Cleaner Production; 162(2017), S133-S145.
Rosca, E.; Bendul, J.; Reedy, J. (2017): Does frugal innovation enable sustainable development? A systematic literature review. In: European Journal for Development Research, pp.1-22. https://doi.org/10.1057/s41287-017-0106-3
Prof. Bendul
Lean Service Management – A systematic literature review 
Originating from the automotive industry, the lean management philosophy has helped many companies in various industries to improve efficiency, quality and stability of processes and therefor to increase customer satisfaction. Over the years, lean management techniques have also been applied in non-factory environments, such as administration, health care or media production. Due to many applications with positive effect, also in the field of service production (e.g. auto shops, logistics, restaurants etc.) lean management techniques are increasingly applied. However, there is no systematic analysis of application (fields), of potentials and challenges available.
The student will conduct a profound and systematic literature review on lean service management. This means, he or she will analyze a set of research articles in a selection of research journals using a pre-defined set of search terms to derive an overview of the status of lean service management. Before, the student needs to familiarize him- or herself with the concepts of lean management and service production as well as with the research method “systematic literature review”. In particular in the phase of selecting, journals, articles and search terms, the student will be closely supervised and supported.If you are interested in this thesis topic, you should make yourself familiar with the basic concepts mentioned. Please prepare a 2-page proposal, in which you state why you think this topic is of practical relevance, why you think that you are the right person to work on such a literature-based on desk research-focused thesis project and your planned schedule.
Prof. Bendul

Bachelor or Master Topics supervised by Dr. Schupp

Development of mechanism to improve material planning between customer and supplier by event driven automated decision making.

The problem the thesis addresses is a lack of transparency between suppliers and customers which causes unnecessary misunderstandings and actions. Through an in-depth analysis of the communication between the two parties and the resulting room for improvement, a mechanism that solves these problems can be developed. The mechanism should automatically decide in what way to change the material planning in certain situations to avoid problems. This part can be a continuation of the pilot project of a first-tier automotive supplier and sub-supplier where transparency has been increased through exchange of data like inventories, demands and production forecasts on a web-platform. This example will also be leading to an analysis of the importance of digitalization in Supply Management. Further topics discussed in the paper will be the legal framework, impact of delivery performance and shortages as well as findings that occurred throughout the research.

Topic Taken
Suggest your own topic via a thesis application.  Dr. Schupp

Bachelor or Master Topics supervised by Prof. Schmidt

Concept of a Competence Center with lab facilities for “Smart Logistics” technologies
Induced by digitization and new technologies, logistics is undergoing partially disruptive changes. The related technologies, such as NB-IoT, 5G, RFID, VR, AR, AI, to name just a few, are partly already in a mature stage (like RFID), under development (like AI) or on the cusp of widespread usage (like 5G). To support their introduction for practical applications, knowledge deficiencies of planners and decision makers in companies have to be overcome. A Competence Center with lab facilities for “Smart Logistics” technologies, potentially affiliated to a research institute, could serve as a consulting and demonstration resource to support making the right choices regarding the usage of such technologies in real-life applications. The concept worked out along with this thesis might become part of an actual competence center in connection with the IFP – Sino-German Institute of Intelligent Technologies in Qingdao, China.
 Prof. Schmidt
Analysis and Assessment of the potentials of the “Belt and Road Initiative (BRI)” (also known as “One Belt One Road (OBOR)” strategy) of the Chinese Government for promoting the exchange of goods between Asia, Africa and Europe
The Belt and Road Initiative (BRI) is a development strategy adopted by the Chinese government involving infrastructure development and investments in countries in Europe, Asia and Africa. “Belt” refers to the overland routes for road and rail transportation, called “the Silk Road Economic Belt”, whereas “road” refers to the sea routes, or the 21st Century Maritime Silk Road. The Belt and Road Initiative addresses an “infrastructure gap” and thus has potential to accelerate economic growth across the Asia Pacific area and Central and Eastern Europe. The thesis shall give an overview of the various activities of the Belt and Road Initiative with focus on logistics aspects and analyze their potential impact on the exchange of goods between Asia, Africa and Europe.
This topic might specifically be suitable for Chinese speaking students.
Prof. Schmidt
Comparative study of the e-commerce supply chains for “non-large” items in Germany and China – markets, structures, players
In both countries, China and Germany, e-commerce plays an important and ever-increasing role in retail. The scope of goods marketed through e-commerce channels encompasses “non-large” items, such as garments, electronics, books etc., “large” items such as furniture and household appliances, food products and others. The thesis shall analyze the supply chains for “non-large” items in both countries, identify the main “players” in the market – both on the retail and the logistics side – and work out similarities and differences in network structures and operation procedures.
This topic might specifically be suitable for Chinese speaking students.
Prof. Schmidt
Comparative study of the CEP markets in Germany and China – structures, players, networks
The markets for Courier-Express-Parcel (CEP) services in Germany and China are an important backbone for the rising e-commerce business. On the other side, retailers go more and more the way to implement their own logistics networks down to the “last mile”, this way not making use of the services of established CEP providers. The thesis shall, against the background of e-commerce, analyze the structures of the CEP markets in Germany and China, give an overview of the main players and their network set-up and investigate potential reasons for retailers to establish their own logistics networks rather than making use of existing CEP service providers.
This topic might specifically be suitable for Chinese speaking students.
Prof. Schmidt
Characteristics and technologies of “Smart Logistics”
“Smart Logistics”, also dubbed “Logistics 4.0”, is an important aspect of the “Industry 4.0” vision formulated by the German National Academy of Science and Engineering in 2013. Focusing on the inbound and outbound Supply Chain, it relates Industry 4.0 concepts to applications in logistics. The thesis shall work out the characteristics of “Smart Logisitcs” when compared to “classical” logistics operations in an industrial environment, summarize important related technological approaches and envision a scenario for an industrial inbound supply chain of the future.
Prof. Schmidt

Bachelor or Master Topics supervised by working group BER (Bremen Energy Research)

Prof. Brunekreeft and his colleagues from the working group Bremen Energy Research (BER) has agreed to supervise the following thesis topics.

1. Impact of digitization on the TFP in the ESI: Solow paradox. Topic Taken
2. Does the economic equivalence VPI=∆w-∆TFP hold in practice? What do the numbers say? The equivalence assumption states that the rate of inflation is equal to the change in input prices minus the change in total factor productivity. Prof. Brunekreeft
3. Risks evolving from digital applications in electricity networks – which/where/how digital technologies will enter the electricity infrastructure and what are the resulting risks? Dr. Buchmann
4. Innovation and electricity networks – how can regulation foster innovation by network operators? Dr. Buchmann
5. Digital Platform economy and the energy sector – Concentration, oligopolies and the need for regulation. Dr. Buchmann
6. The Role of Aggregators in the Electricity Supply Industry – Business models and technical and regulatory challenges. Dr. Meyer
7. Demand Side Management and Smart Electricity Grids – System Benefits and market design issues. Dr. Meyer
8. E-Mobility – Prospects and challenges of integrating electric vehicles into electricity distribution networks. Dr. Meyer

Bachelor or Master Topics supervised by Prof. Hütt

Prof. Hütt (Professor of Systems Biology at Jacobs University) has agreed to supervise the following thesis topics. Please approach him directly in case of any questions.

Time constants of biological enzymes as machine capacities
Metabolism is a production process in biological cells, where enzymes (the ‘machines’) convert chemical compounds (metabolites) into other chemical compounds, leading to an intricate network of interacting machines. The striking parallel between metabolism and industrial production systems offers the fascinating possibility to compare evolved and designed systems. As ever more information on metabolic systems becomes electronically available in bioinformatics databases, this parallel can now be quantitatively explored. The goal of the project is to use production planning algorithms for machine capacities, apply them to a metabolic network and see, whether the actual capacities (given by the inverse time constants of enzymes and available via databases) match those predictions.Further reading:
Beber, M. E. and Hütt, M. (2012). How do production systems in biological cells maintain their function in changing environments? Logistics Research, 5(3-4):79–87.
Prof. Hütt
Product diversity and network structure: a minimal model

A comparatively unexplored aspect of manufacturing is the relationship between the production network and the diversity of the manufactured products. Previous work on evolved flow networks (Beber et al. 2013) has shown that the network architecture is strongly affected by the complexity of the network’s required ‘output pattern’. In a series of small investigation we want to understand this phenomenon more deeply and apply the findings to manufacturing.
The goal of the project component described here is to formulate heuristics for generating a production network for a given product structure using path combinatorics. Then the network architectures will be statistically analyzed in order to establish relationships between product diversity and network structure.

Further reading:
Beber, M., Armbruster, D. and Hütt, M.-Th. (2013) The prescribed output pattern regulates the modular structure of flow networks. European Physical Journal B 86, 473. DOI: 10.1140/epjb/e2013-40672-3.

Prof. Hütt
Product diversity and network structure: analysis of evolved flow networks

A comparatively unexplored aspect of manufacturing is the relationship between the production network and the diversity of the manufactured products. Previous work on evolved flow networks (Beber et al. 2013) has shown that the network architecture is strongly affected by the complexity of the network’s required ‘output pattern’. In a series of small investigation, we want to understand this phenomenon more deeply and apply the findings to manufacturing.
The goal of the project component described here is to analyze the database from Beber et al. (2013) from the perspective of novel network properties: linearity, path combinatorics and betweenness centrality.

Further reading:
Beber, M., Armbruster, D. and Hütt, M.-Th. (2013) The prescribed output pattern regulates the modular structure of flow networks. European Physical Journal B 86, 473.

Prof. Hütt
Product diversity and network structure: analysis of real production networks

A comparatively unexplored aspect of manufacturing is the relationship between the production network and the diversity of the manufactured products. Previous work on evolved flow networks (Beber et al. 2013) has shown that the network architecture is strongly affected by the complexity of the network’s required ‘output pattern’. In a series of small investigation we want to understand this phenomenon more deeply and apply the findings to manufacturing.
The goal of the project component described here is to study, whether similar relationships are also observed in real manufacturing systems. To this end, product diversity will be analyzed and then statistically compared with the system’s material flow networks.

Further reading:
Beber, M., Armbruster, D. and Hütt, M.-Th. (2013) The prescribed output pattern regulates the modular structure of flow networks. European Physical Journal B 86, 473.

Prof. Hütt
Synchronization as a quantifier of activity patterns: delay avalanches

The various concepts of synchronization attempt to capture the pattern of activity in a production network. It has been established before that high synchronization can lead to system-wide failures and thus reduce the robustness of the system against perturbations (Fretter et al. 2010). This project uses the general model paradigm of ‘avalanches on graphs’ to study this phenomenon further: How does the network architecture facilitate such avalanches? Can we adapt standard avalanche models to account for lateness propagation in production systems?

Further reading:
Fretter, C., Krumov, L., Weihe, K., Müller-Hannemann, M. and Hütt, M.-Th. (2010) Phase synchronization in railway timetables, European Physical Journal B 77, 281-289.

Prof. Hütt
Synchronization as a quantifier of activity patterns: activity as excitable dynamics

The various concepts of synchronization attempt to capture the pattern of activity in a production network. It has been established before that high synchronization can lead to system-wide failures and thus reduce the robustness of the system against perturbations (Fretter et al. 2010). This project asks, how different types of synchronization (termed logistics synchronization and physics synchronization in Chankov et al. 2015) quantify activity patterns in a graph, and thus ‘calibrate’ these measures. In order to understand the generic properties of these synchronization measures, we will use a simple model of activity, namely excitable dynamics on graphs (see, e.g., Müller-Linow et al. 2008) to simulate activity patterns and then analyze the synchronization measures as a function of network architecture and parameters of the dynamics.

Further reading:
Fretter, C., Krumov, L., Weihe, K., Müller-Hannemann, M. and Hütt, M.-Th. (2010) Phase synchronization in railway timetables, European Physical Journal B 77, 281-289.
Chankov, S., Bendul, J. and Hütt, M.-Th. (2015) Synchronization in Manufacturing Systems: Quantification and Relation to Logistics Performance. International Journal of Production Research, under review.
Müller-Linow, M., Hilgetag, C. and Hütt, M.-Th. (2008) Organization of excitable dynamics in hierarchical biological networks. PLoS Computational Biology 4, e1000190.

Prof. Hütt
Sequentiality and linearity of production networks

Important properties of manufacturing processes are determined by the combinatorics of paths in the material flow network (see Garcia et al. 2014 for an example, how such a question is investigated for closed paths). Deterministic linear sequences in this material flow ‘decouple’ parts of the system from other parts. The amount of linearity in a production network is therefore an important architectural quantity. While there is no standard way of measuring the linearity of a network, a rich set of network quantifiers has emerged over the last years addressing aspects of this question. The purpose of this project is to perform a literature review of these quantifiers and then compare them using a small set of reference networks with varying amounts of linearity.

Further reading:
Garcia, G.C., Lesne, A., Hilgetag C.C. and Hütt, M.-Th. (2014) The role of topological cycles in excitable dynamics on graphs. Phys. Rev. E 90, 052805.

Prof. Hütt
The graph chromatic number as a robustness indicator of production networks

The graph coloring problem (distribute colors from a list on a graph such that no same colors are linked) is related to many scheduling problems in logistics. Attempting to distribute the colors based on local decisions only generates coloring dynamics, which are a minimal model of autonomous control (see, e.g., Windt and Hütt 2010). Given a graph, the minimal number of colors for which the graph coloring problem can be solved is called the ‘chromatic number’ of the graph. Qualitatively speaking, this quantity determines, how easy scheduling is on the graph. We can expect that logistics performance of, e.g., a production network will depend strongly on this chromatic number. Using numerical experiments with scheduling software this relationship will be explored.Further reading:
Windt, K. and Hütt, M.-Th. (2010) Graph Coloring Dynamics: A Simple Model Scenario for Distributed Decisions in Logistics. CIRP Annals Manufacturing Technology 59, 461-464.
Prof. Hütt
Network recovery: a literature review with small numerical experiments

How networks recover from perturbations is a general question with deep implications for logistics systems. As an example, in Hao et al. (2015) the performance of a distributed insurance system under spatially and temporally correlated failures has been studied. The goal of this project is to understand, how the recovery of (production or distribution) networks is influenced by their architecture. The starting point will be a literature review of attempts to quantify and analyze network recovery. This survey of theoretical studies will be complemented by own numerical experiments on network recovery.

Further reading:
Hao, Y., Armbruster, D. and Hütt, M.-Th. (2015) Node survival in networks under correlated attacks. PLoS One, in press.

Prof. Hütt
Network representations of production systems

Across many disciplines, the formal language of nodes and links provides an efficient data structure for representing complex systems. Such representations can help comparing diverse systems.  In the case of production systems, nodes can be machines, processes, inventories, products at intermediate stages of production, or check points. Links can represent material flow, regulation, control and decision alternatives.
As an example, in Becker et al. (2011) production systems are represented as networks of cyclically operating devices. In this way, a comparison with traffic networks and production systems in biological cells (metabolic networks) could be achieved.
The goal of this project is to review the different network representations of production systems and analyze, how these network representations can help understand the functioning of these systems.

Further reading:
Becker, T., Beber, M.E., Windt, K., Hütt, M.-Th. and Helbing, D. (2011) Flow control by periodic devices: A unifying language for the description of traffic, production, and metabolic systems. J. Stat. Mech, P05004.

Prof. Hütt
Production networks vs. information processing networks

Across many disciplines, the formal language of nodes and links provides an efficient data structure for representing complex systems. Such representations can help comparing diverse systems.
Such networks tend to fall into two classes: production networks, characterized by their material flow, and information processing networks, characterized by their flow of information.
The goal of this project is a high-level comparison of these two classes of networks: What are the main functional differences (e.g., conservation laws)? Do they differ systematically in their architectures? How do the functional requirements differ for these networks? What do efficiency and robustness mean in each class?

Prof. Hütt
Random walks as a reference model for material flows

Understanding the material flow in manufacturing systems and its impact on logistics performance indicators is one of the principal goals production logistics. In many complex systems, a proper analysis of available data is only possible when contrasted to suitable versions of random data. Here, a simple model for random material flows, based on random walks, will be explored. Over the last decade, random walks on graphs have dramatically enhanced our understanding of the scaling of fluctuations in networks (see, e.g., Kosmidis et al. 2015). The goal of this project is to introduce modifications to a standard random walk (like a preference to move from an input layer to an output layer of the network) and study, how well the random walk reproduces statistical features of real material flows in manufacturing.

Further reading:
Kosmidis, K., Beber, M. and Hütt, M.-Th. (2015) Network heterogeneity and node capacity lead to heterogeneous scaling of fluctuations in random walks on graphs. Advances in Complex Systems 18, 1550007.

Prof. Hütt
Scaling laws in production logistics

Scaling relationships are among the most surprising findings about complex social and technological systems: laws allowing to predict with high accuracy the number of patents, crimes and restaurants just from the population size (see Bettencourt and West 2010); laws relating the number of machines to the number of regulators in production systems in biological cells (Maslov et al. 2009). The goal of this project is the search for such scaling laws in production systems. The starting point will be a survey of publically available databases about company sizes and infrastructures.

Further reading:

Bettencourt, L, and Geoffrey West, G.B. (2010) A unified theory of urban living. Nature 467, 912-913.

Maslov, S., Krishna, S., Pang, T. and Sneppen, K. (2009) Toolbox model of evolution of prokaryotic metabolic networks and their regulation. PNAS 106, 9743.

 Prof. Hütt