Prof. Dr. André Ludwig

Associate Professor of Computer Science in Logistics

Publications

Journal Articles (Peer-Reviewed)

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Abstract: In the past, logistics used to be a core function of production and trading companies but many of them started to outsource at least parts of their logistics functions to specialized logistics service providers in terms of logistics contracts. With this, sophisticated business models such as value added logistics service providers evolved which focus on tasks of planning, coordination and monitoring of entire supply chains involving multiple logistics providers. Challenges remain though, for instance how a complex logistics contract can be planned and how it can be assured that the providers comply with the planned process. In this article, we present a conceptual as well as technical solution to the monitoring of logistics services and show how to reuse this information in a model for the integrated planning of logistics contracts. A simulation model thereby ensures validity of the overall planning. An approach for integrating different models helps to overcome the problem of utilizing multiple models. Finally, an example scenario shows how each part contributes to a successful planning process for logistics contracts.

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Abstract: Service compositions enable users to realize their complex needs as a single request. Despite intensive research, especially in the area of business processes, web services and grids, an open and valid question is still how to manage service compositions in order to satisfy both functional and non-functional requirements as well as adapt to dynamic changes. This article describes an approach towards adaptive management of QoS aware service compositions. This approach integrates well known concepts and techniques and proposes various execution strategies based on dynamic selection and negotiation of services included in a service composition, contracting based on service level agreements, service enactment with flexible support for exception handling, monitoring of service level objectives, and profiling of execution data. An important element of the approach is an open architecture for adaptive service composition management. Its first prototypical implementation has been developed within an EU-funded Adaptive Service Grid project.

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Journal Articles (Professional)

Copy reference link   DOI: doi:10.1007/s35764-016-0082-y

Abstract: Nach wie vor ist das Thema Datenschutz eine der größten Herausforderungen bei der Nutzung von Cloud-Systemen. Eine Möglichkeit zur Sicherstellung des Datenschutzes besteht in der Dezentralisierung der Datenhaltung und Datenzugriffssteuerung. In diesem Artikel stellen wir eine Systemarchitektur für dezentrale Datenhaltung und Datenschutz auf Basis von Storage Clouds vor. Dabei werden die Datenbestände dezentral in Private-Cloud-Systemen durch Nutzer selbst verwaltet. Eine unabhängige Administrationskomponente regelt die Zugriffs- und Verteilungsrechte auf diese Daten. Ein von uns entwickelter Prototyp zeigt die Umsetzung am Beispiel eines sozialen Netzwerks.

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Books

Conference Proceedings

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Abstract: With an ongoing division of labor and concentration on core competencies in logistics, the flexibility and quality in logistics services can be increased in terms of contracting specialists for each step in a supply chain. In order to participate in such an environment and act successfully on the market, it is essential for logistics service providers to follow a service oriented paradigm and modularize their service portfolio from static end-to-end solutions to a flexible set of modular services. One of the main challenges is to find a ’suitable’ level of granularity for the modularization of existing logistics services. In this paper a conceptual framework of service granularity levels is developed. A systematic literature review is conducted in order to find existing concepts of service granularity. Findings are analyzed and finally synthesized towards their suitability for logistics services. Domain specific composition is supported by the logistics service map concept that contains catalog and construction kit for modular services. The paper’s contribution is a Service Granularity Framework dedicated to specialized scholars of service science and practitioners of logistics.

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Copy reference link   DOI: 10.1007/978-3-319-19027-3_23

Abstract: Global demands and emerging markets resulted in a rise of complexity in logistics over the last years. Furthermore, producing companies outsourced their logistics for reasons of flexibility. Hence, clients consult solution specialists for customer-focused end-to-end processes. The 4th party logistics business model offers an overall service management throughout an entire logistics chain by planning and controlling inherent processes. But because physical provisioning is outsourced to 3rd party providers, performance measurement is essential in order to meet service levels. Measuring sub providers poses difficulties because of different process definitions and communication standards. A relief is the growing amount of information during the process lifecycle. In this paper we present an integrated, strategically aligned provider rating model, applicable throughout the entire logistics process and capable of summing up operational information into ratios that are further aggregated into key performance indicators. Thereafter, we prove its applicability through a prototypical implementation.

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Copy reference link   DOI: 10.5220/0005377801660176

Abstract: The objective of tactical planning in logistics is the engineering and evaluation of processes within a given set of possible alternatives. Due to outsourcing and a division of labor, a high number of participants, available services and thus possible process alternatives arises within logistics networks. The additional wide range of service description and annotation methods result in a complex planning process. In order to support planning, a semi-automated approach is presented in this paper that is based on a combined catalog and construction system (for engineering) and a generic simulation approach (for evaluation) that are able to handle the variety of description and annotation methods. The basic concepts are presented and afterward associated by a model-driven approach in order to connect them and make them compatible to work with each other. Finally, a method is developed to foster a semi-automated engineering and evaluation of process alternatives.

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Copy reference link   DOI: 10.1007/978-3-319-06695-0_16

Abstract: With the principle of division of labor in logistics, an integrator can focus on planning and monitoring within a network, while subsidiary logistics service providers (LSPs) are responsible for the actual physical manipulation of goods. Because of heterogeneous service descriptions, processes and IT-systems, the integrator requires a platform that provides the ability to interact with LSPs and to plan, execute and monitor contracts for integrator’s customers. Such an integration platform is currently developed in the research project Logistics Service Engineering & Management. Crucial to such a platform is the ability to maintain a complete catalog and to efficiently identify and choose appropriate services. In this paper a metamodel-based approach is presented facing these requirements.

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Copy reference link   DOI: 10.1007/978-3-319-06695-0_22

Abstract: Driven by rising competitive constraints companies began to outsource at least parts of their internal activities to specialized external logistics providers in terms of contracts. Thereby, new business models like the fourth party logistics evolved, which acts like coordinator of the emerging logistics networks. The main task of the provider is the planning, monitoring and measurement of the different networks of its customers. Based on a method to integrate process modeling and their simulation, complex event processing to gather real-time information about process executions and service profiles to measure subsequent service providers’ quality – a closed loop approach for improving the quality of service provisioning is presented.

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Copy reference link   DOI: 10.1007/978-3-642-38827-9_26

Abstract: The logistics service industry is characterized by a high level of collaboration between logistics customers and providers. In fact, sophisticated, knowledge-intense business models such as fourth party and lead logistics evolved in recent years that are responsible for planning, coordination, and monitoring entire supply chains across logistics companies. The Logistics Service Engineering and Management (LSEM) platform is a service-oriented infrastructure for the development and management of collaborative contract logistics enabling fourth party and lead logistics. The service modeling framework (SMF) is a central element of the LSEM-platform. It allows users of the platform to define, manage and combine logistics services from different providers and allows for an integrated view on complex services setups. In this paper, the Service Meta Modeling Editor is presented as an essential part of the SMF. It allows connecting and integrating various types of service models and avoids the need to define and maintain a complex, global service model. Instead a comprehensive service model is built bottom-up in that elements from different models are linked on a metamodel level.

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Abstract: Der Logistikdienstleistungssektor ist gekennzeichnet durch arbeitsteilige, kurz- und mittelfristige Zusammenarbeit von spezialisierten Logistikdienstleistern. Insbesondere sogenannte Fourth Party Logistics (4PL) Dienstleister stehen permanent vor der Aufgabe, unterschiedliche Logistikdienstleister und deren Informationssysteme ad hoc und ohne Medienbrüche in unternehmensübergreifende Informationsflüsse zu integrieren. Die Logistik Service Engineering & Management (LSEM) Plattform als Integrationsplattform für 4PL nimmt diese Anforderungen auf und stellt einen stufenweisen, modellgetriebenen Integrationsansatz bereit. In diesem Beitrag werden neben der LSEM Plattform selbst, die durch die Plattform unterstützen Integrationsarten vorgestellt. Näher beschrieben wird daneben ein Lösungsansatz zur modellgetriebenen Integration vonAnwendungssystemen in die LSEM Plattform.

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Abstract: The success of an enterprise is largely determined by its ability andflexibility to react to changes and its business process stability and safeness. Innovative technologies help to improve the execution and management of business processes and ensure that a competitive position can be achieved or enhanced. Radio frequency identification is such an innovative technology with a high potential of optimisation within business processes for example for reduction of processing time and failure rates. By means of a practical case study this paper gives recommendations and shows how RFID can improve business processes.

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Abstract: SSME and SOA are strongly connected perspectives. SOA modelingprocedures, SOA management methodologies, SOA role concepts, and many otherimportant aspects heavily depend and base on specific SOA service types defined in aservice taxonomy. However, currently we are far from a consistent taxonomicunderstanding which causes communication problems regarding nearly all SOA issueshampering research as well as implementation efforts in this field. This paper reflects thecurrent state of discussion by mapping several relevant proposals and presents a basicservice taxonomy aiming at stopping the proliferation of service types. This basictaxonomy can be used as a basis for domain- or project-specific taxonomic refinements.

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Abstract: Service oriented architecture (SOA) has emerged as a popular software paradigm for integrating distributed applications. Services are generally regarded as interoperable building blocks for constructing, integrating, and merging applications. However, existing SOA based solutions often focus on solving technical integration problems while neglecting business-level capabilities which are most important for organizations. In this paper, we introduce the notion of capabilities as an important concept for business management. We identify major shortcomings of the existing service based solutions and outline a novel approach for capability oriented configuration and management that can react to the dynamically changing nature of business integration environments.

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Copy reference link   DOI: 10.5220/0003982502590264

Abstract: A recurring task when managing logistics networks in which logistics companies jointly offer services is the comparison of logistics services based on their underlying processes. The comparison is necessary for the integration of processes, the selection of logistics providers and the evaluation of a company's performance. Due to a high diversity of logistics services and their properties as well as due to the high amount of services automated logistics service comparison is needed to support this task. This paper presents basic requirements and evaluates the state of the art with regard to these requirements. In addition, an initial solution approach providing a solid base for future work is outlined.

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Copy reference link   DOI: 10.1109/SCC.2014.125   DOI: http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=6930627

Abstract: This paper introduces the concept of the Logistics Service Map, a modular service construction system with an inherent catalog function. Specialized service providers, so called logistics integrators are to use this concept to integrate subsidiary service providers into logistics networks. The main purpose of the Service Map is to enable and to foster the development of atomic as well as composite logistics services used by the integrator to fulfill customers' requirements. After a brief presentation of the applied research methodology, the current progress of research is outlined and a draft of future research activities and discussion points is given.

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Copy reference link   DOI: 10.1109/FSKD.2008.208   DOI: http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=4666452

Abstract: Service provisioning is largely built on agreements specifying the mutual responsibilities of service providers and their customers with respect to functional and non-functional parameters. However, the dynamics that result from the service-oriented computing paradigm in particular in composite services place new challenges onto the management of composite service level agreements which could not be achieved yet. This paper discusses the management of SLAs involved in composite services using the COSMA approach. After introducing the COSMA approach, the usage of COSMAdoc instances for negotiating SLAs in composite services is presented in detail.

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Copy reference link   DOI: 10.1109/SRII.2012.22

Abstract: The logistics industry is characterized by a high level of collaboration between logistics customers and providers. In fact, sophisticated, knowledge-intense business models such as 4th party logistics providers that are responsible for planning, coordination, and monitoring entire supply chains across logistics companies can be observed. However, integrated approaches for engineering and management of fourth party logistics are rather in its infancy. The Logistics Engineering and Management platform is a service-oriented approach for the development and management of long and mid-term logistics contracts. It serves as a collaboration platform and integrates services from different logistics providers. In this paper a core feature of the platform is presented, a service repository as a single point of truth coping with the complexity of miscellaneous service descriptions and models. Central idea behind this repository is the integration of different specialized service models and the construction of a comprehensive model, which supports direct implementation of services as concrete logistics tasks. In this article we present preliminary results of the service repository's development and realization and an outlook for future research.

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Copy reference link   DOI: 10.1109/SCC.2009.38   DOI: http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=5283907

Abstract: The development of enterprise-wide service-oriented architectures (SOA) is a complex task. In most cases, evolutionary approaches are used to deal with the arising complexity. However, most of the existing design methodologies and implementation strategies focus on more technical, service realization specific aspects. Challenges regarding the definition and the management of related service artifacts throughout the whole service lifecycle are neglected. Also the implementation of a lifecycle-encompassing information management infrastructure is not addressed adequately in research and industry. In this paper we introduce a common service management information model (coSIM) that builds a foundation for the management of services and service infrastructures during design-, run- , and change-time.

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Abstract: Many use cases in business process management rely on the identification of correspondences between process models. However, the sparse information in process models makes matching a fundamentally hard problem. Consequently, existing approaches yield a matching quality which is too low to be useful in practice. Therefore, we investigate incorporating user feedback to improve matching quality. To this end, we examine which information is suitable for feedback analysis. On this basis, we design an approach that performs matching in an iterative, mixed-initiative approach: we determine correspondences between two models automatically, let the user correct them, and analyze this input to adapt the matching algorithm. Then, we continue with matching the next two models, and so forth. This approach improves the matching quality, as showcased by a comparative evaluation. From this study, we also derive strategies on how to maximize the quality while limiting the additional effort required from the user.

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Copy reference link   DOI: 10.1109/ICCSIT.2009.5234431   DOI: http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=5234431

Abstract: The development of enterprise-wide service-oriented architectures (SOA) is a complex task. In most cases, evolutionary approaches are used to deal with the arising complexity. However, most of the existing design methodologies and implementation strategies focus on more technical, service realization specific aspects. Challenges regarding the definition and the management of related service artifacts throughout the whole service lifecycle are neglected. Also the implementation of a lifecycle-encompassing information management infrastructure is not addressed adequately in research and industry. In this paper we introduce a common service management information model (coSIM) that builds a foundation for the management of services and service infrastructures during design-, run- , and change-time.

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Abstract: Die Service-Bereitstellung in Service-Oriented-Computing-Umgebungen wird durch Service Level Agreements (SLA) beschrieben. Aktuelle SLA-Management-Ansätze konzentrieren sich auf bilaterale Service-Provider-/-Requester-Konstellationen, gehen jedoch nicht auf SLA-Management- Anforderungen von Composite Service Providern ein. Diese betreffen das SLA-Management mit Providern von Atomic Services, mit Requestern von Composite Services und deren Abstimmung aufeinander. Ein Composite SLA Management Ansatz muss den Anteil von (Atomic) SLAs beim SLA-Management von (Composite) SLAs berücksichtigen. Der COSMA-Ansatz erlaubt ein integriertes Management von Atomic und Composite SLAs während deren gesamten Lebenszyklus. Er ermöglicht die Abbildung der Abhängigkeiten und Beziehungen zwischen unterschiedlichenSLAs und damit eine Kontrolle, Steuerung und Optimierung der SLA-Management-Aktivitäten.

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Book Chapters

Copy reference link   DOI: 10.1007/978-3-642-40176-3_17

Abstract: Comparing process models and matching similar activities has recently emerged as a research area of business process management. However, the problem is fundamentally hard when considering realistic scenarios: e.g., there is a huge variety of terms and various options for the grammatical structure of activity labels exist. While prior research has established important conceptual foundations, recall values have been fairly low (around 0.26) – arguably too low to be useful in practice. In this paper, we present techniques for activity label matching which improve current results (recall of 0.44, without sacrificing precision). Furthermore, we identify categories of matching challenges to guide future research.

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Copy reference link   DOI: 10.1007/978-3-642-21863-7_21

Abstract: The logistics service sector is faced with a growing complexity which needs to be handled by cooperating logistics providers aligning their services in a network. This paper introduces the Logistics Service Engineering and Management platform supporting the Fourth Party Logistics Provider business model that aims at establishing a coordinator of such a network. Hence the idea to employ the service oriented design paradigm at the software and at the business level along with the main features of the platform is presented. Furthermore the basic architecture is explained and a closer look at some implementation details is presented.

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Copy reference link   DOI: 10.1007/978-3-642-12814-1_21

Abstract: Business capabilities represent potentials of an organisation to reach a specific goal or outcome. Business capabilities abstract from processes, resources and people that are required to provide the potential and are connected with a role model of provider and customer, both, internally and externally to an organisation. While related work provides fundamental concepts and usage descriptions of the business capability approach, so far the aspect of visualisation of business capabilities in the context of business analysis was only rudimentary addressed. In this paper, a three-dimensional business capability visualisation metaphor for business analyses is outlined which supports the visualisation of business capabilities and their qualifying dimensions but also the representation of their complex multi-dimensional interrelations.

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Abstract: COSMA proposes a novel SLA management approach for composite services. It supports a composite service provider in managing SLAs with providers of atomic services, in managing SLAs with requesters of composite services, and aligning both SLA management activities with each other. On this basis, a composite service provider can control and optimize its composite SLA management activities during the entire SLA lifecycle. This includes, in particular, planning and negotiating SLAs, monitoring and evaluating SLAs. In this paper, a case study on managing SLAs in composite services with the COSMA approach is presented in detail.

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Abstract: Gegenstand des vorliegenden Beitrags ist ein Phasenmodell,das der Entwicklung einer branchenspezifischen Shared-Services-Plattform dient.Das Phasenmodell wurde im Rahmen eines vom Bundesministerium für Bildungund Forschung finanzierten Projektes entwickelt und wird anhand der Erstellungeiner Logistik-Service-Bus-Plattform praktisch eingesetzt. Der Beitrag umreißt dasgesamte Vorgehen und fokussiert aufgrund ihrer herausragenden Bedeutung diebeiden ersten Phasen.

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Copy reference link   DOI: 10.1007/978-3-540-89652-4_56

Abstract: Service provisioning is largely built on agreements specifying the mutual responsibilities of service providers and their customers with respect to functional and non-functional parameters. Current SLA management approaches, i.e. WSLA, WS-Agreement, or WSOL, provide extensive SLA language formalizations and management frameworks. However, they focus on bi-lateral service requester/provider constellations neglecting the SLA management requirements of composite service providers, i.e. managing SLAs with atomic service providers and with composite service requesters and aligning both with each other. A SLA management solution for composite services has to consider the contribution of sourced services - formalized in their (atomic) SLAs (ASLA) - in the management of the provided service - formalized in its respective (composite) SLA (CSLA). This paper presents the novel COmposite Sla MAnagement (COSMA) approach for an integrated management of atomic and composite SLAs during their entire lifecycle. It can be utilized for controlling the relationships between ASLAs/CSLAs and thus serves as the basis for managing and optimizing the SLAs involved in composite services.

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Copy reference link   DOI: 10.1007/978-3-540-78617-7_5

Abstract: Service composition enables the creation of services previously unavailable through the aggregation of existing services. The result is called a service composition. Exposing a service composition as a service, the result is called a composed service. It can be distinguished from atomic services. Service composition approaches can be differentiated along two axes: point in time of composition and degree of automation. With design-time and run-time we can identify two different points in time for doing a composition. Additionally we can distinguish between three different degrees of automation: manual, assisted, and automated service composition.

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Abstract: Service compositions enable users to realize their complex needs as a single request. Despite intensive research, especially in the area of business processes, web services and grids, an open and valid question is still how to manage service compositions in order to satisfy both functional and non-functional requirements as well as adapt to dynamic changes. In this paper we describe an approach towards adaptive management of QoS-aware service compositions. This approach integrates well known concepts and techniques and proposes various execution strategies based on dynamic selection and negotiation of services, contracting based on service level agreements, service enactment with flexible support for exception handling, monitoring of service level objectives, and profiling of execution data.

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Copy reference link   DOI: 10.1007/11948148_61

Abstract: Service compositions enable users to realize their complex needs as a single request. Despite intensive research, especially in the area of business processes, web services and grids, an open and valid question is still how to manage service compositions in order to satisfy both functional and non-functional requirements as well as adapt to dynamic changes. In this paper we propose an (functional) architecture for adaptive management of QoS-aware service compositions. Comparing to the other existing architectures this one offers two major advantages. Firstly, this architecture supports various execution strategies based on dynamic selection and negotiation of services included in a service composition, contracting based on service level agreements, service enactment with flexible support for exception handling, monitoring of service level objectives, and profiling of execution data. Secondly, the architecture is built on the basis of well know existing standards to communicate and exchange data, which significantly reduces effort to integrate existing solutions and tools from different vendors. A first prototype of this architecture has been implemented within an EU-funded Adaptive Service Grid project.

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Abstract: An important aspect of managing service-oriented grid environments ismanagement of agreement relationships between service providers and theircustomers. The key concept in addressing these agreements is service levelagreement. In this paper we motivate the need for SLA lifecycle management inservices grid and present results of our analysis on functional and non-functionalrequirements. Afterwards the state of the art in managing service level agreementsis revisited by a comprehensive evaluation of current efforts and their respectivestrength and weaknesses in service level agreement lifecycle management systems.The results of this evaluation have been applied to the development of the openmanagement platform Adaptive Service Grid which is an EU founded researchproject.

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