Andreas Wombacher

University of Twente | UT · Centre for Telematics and Information Technology (CTIT)

Processes can synchronize their states by exchanging messages. System crashes and network failures may cause message loss, so that state changes of a process may remain unnoticed by its partner processes, resulting in state inconsistency or deadlocks. In this paper we define a method to transform a business process into its recovery-enabled counter...

This paper presents a remote sensing technique for calibrating hydrodynamics models, which is particularly useful when access to the riverbed for a direct measure of flow variables may be precluded. The proposed technique uses terrestrial photography and automatic pattern recognition analysis together with digital mapping and does not require image...

With the possibility of system crashes and network failures, the design of robust client/server interactions for collaborative process execution is a challenge. If a business process changes its state, it sends messages to the relevant processes to inform about this change. However, server crashes and network failures may result in loss of messages...

Decision making, process control and e-science applications process stream data, mostly produced by sensors. To control and monitor these applications, reproducibility of result is a vital requirement. However, it requires massive amount of storage space to store fine-grained provenance data especially for those transformations with overlapping sli...

Many applications facilitate a data processing chain, i.e. a workflow, to process data. Results of intermediate processing steps may not be persistent since reproducing these results are not costly and these are hardly re-usable. However, in stream data processing where data arrives continuously, documenting fine-grained provenance explicitly for a...

In stream data processing, data arrives continuously and is processed by decision making, process control and e-science applications. To control and monitor these applications, reproducibility of result is a vital requirement. However, it requires massive amount of storage space to store fine-grained provenance data especially for those transformat...

Fine-grained data provenance ensures reproducibility of results in decision making, process control and e-science applications. However, maintaining this provenance is challenging in stream data processing because of its massive storage consumption, especially with large overlapping sliding windows. In this paper, we propose an approach to infer fi...

Sensor data can be interpreted as a view on physical objects effected by business processes. Since both sensor infrastructures and business workflows must deal with imprecise information, the correlation of sensor data and business workflow data might be used a-posteriori to determine the source of the imprecision. In this paper, information theory...

Service Oriented Architectures ease integration of heterogeneous systems, such as sensor data and workflow systems. Systems are integrated since they model an overlapping part of the physical world, i.e., physical objects exchanged between different parties. For workflows handling physical objects, the correlation of sensor data with workflow state...

For companies managing complex Web service compositions, challenges arise which go far beyond simple bilateral contract monitoring. For example, it is not only important to determine whether or not a component (i.e., Web service) in a composition is performing properly, but also to understand what the impact of its performance is on the overall ser...

During the last decade a new generation of process-aware information systems has emerged, which enables process model configurations at buildtime as well as process instance changes during runtime. Respective adaptations result in a large number of process model variants that were derived from the same process model, but slightly differ in structur...

River restoration has become a common measure to repair anthropogenically-induced alteration of fluvial ecosystems. The inherent complexity of ecohydrologic systems leads to limitations in understanding the response of such systems to restoration over time. Therefore, a significant effort has been dedicated in the recent years worldwide to document...

Often data processing is not implemented by a workflow sys-tem or an integration application but is performed manually by humans along the lines of a more or less specified procedure. Collecting prove-nance information during manual data processing can not be automated. Further, manual collection of provenance information is error prone and time co...

Cloud computing is already a major trend in IT. Cloud services are being offered at application (software), platform and infrastructure levels. This paper presents our initial modeling efforts towards service creation at the infrastructure level. The purpose of these modeling efforts is to understand and reason about the service creation process. T...

River restoration has become a common measure to repair anthropogenically-induced alteration of fluvial ecosystems. The inherent complexity of ecohydrologic systems, leads to limitations in understanding the response of such systems to restoration over time. Up to now a lot of effort has therefore been dedicated worldwide to document the efficiency...

During the last years a new generation of adaptive Process-Aware Information Systems (PAIS) has emerged, which enables dynamic process changes at runtime, while preserving PAIS robustness and consistency. Such adaptive PAIS allow authorized users to add new process activities, to delete existing activities, or to change pre-defined activity sequenc...

Inter-organizational cooperations are complex in terms of coordination, agreements, and value creation for involved partners. When managing complex cooperations, it is vital to maintain models describing them. Changing one model to regain consistency with the running system might result in new inconsistencies. As a consequence, this maintenance pha...

The standard training method of Conditional Random Fields (CRFs) is very slow for large-scale applications. As an alternative, piecewise training divides the full graph into pieces, trains them independently, and combines the learned weights at test time. In this paper, we present \emph{separate} training for undirected models based on the novel Co...

Service discovery of state dependent services has to take workflow aspects into account. To increase the usability of a service discovery, the result list of services should be ordered with regard to the relevance of the services. Means of ordering a list of workflows is a similarity measure of the workflow and a query. In this paper different simi...

Real-time operated wireless sensor networks produce large amounts of data, so that typical eyeball based analysis of data comes to its limits. Consequently we have to adapt and automate our data handling and archiving procedures, as well as our data analysis tools. Management of sensor data requires metadata to understand the semantics of observati...

E-science applications use fine grained data provenance to maintain the reproducibility of scientific results, i.e., for each processed data tuple, the source data used to process the tuple as well as the used approach is documented. Since most of the e-science applications perform on-line processing of sensor data using overlapping time windows, t...

One of the major requirements for e-science applications handling sensor data, is reproducibility of results. Several optimization and scalability problems exist where the reproducibility of results remains guaranteed. Firstly, various data streams need to be coordinated to optimize the accuracy and processing of the results. Secondly, because of t...

In the field of e-science stream data processing is common place facilitating sensor networks, in particular for prediction and supporting decision making. However, sensor data may be erroneous, like e.g. due to measurement errors (outliers) or changes of the environment. While it can be foreseen that there will be outliers, there are a lot of envi...

Online data or streaming data are getting more and more important for enterprise information systems, e.g. by integrating sensor data and workflows. The continuous flow of data provided e.g. by sensors requires new workflow models addressing the data perspective of these applications, since continuous data is potentially infinite while business pro...

Management of sensor data requires metadata to understand the semantics of observations. While e-science researchers have high demands on metadata, they are selective in entering metadata. The claim in this paper is to focus on the essentials, i.e., the actual observations being described by location, time, owner, instrument, and measurement. The a...

Recently, a new generation of adaptive Process-Aware Information Systems (PAISs) has emerged, which enables structural process changes during runtime. Such flexibility, in turn, leads to a large number of process variants derived from the same model, but differing in structure. Generally, such variants are expensive to configure and maintain. This...

Many companies offer physical products combined with on-line services. For example, product configuration, ordering, order tracking, and payments can be done on-line. The service part of the total offering (the composition) is typically composed of services offered by providers where performance of both the composition (provided by the company) and...

Recently, a new generation of adaptive process management technology has emerged, which enables dynamic changes of composite services and process models respectively. This, in turn, results in a large number of process variants derived from the same process model, but differing in structure due to the applied changes. Since such process variants ar...

In previous research we introduced the MoDe4SLA approach for monitoring service compositions. MoDe4SLA identifies complex dependencies between Service Level Agreements (SLAs) in a service composition. By explicating these dependencies, causes of SLA violations of a service might be explained by malfunctioning of the services it depends on. MoDe4SLA...

An essential issue in peer-to-peer data management is to keep data highly available all the time. The paper presents a replication protocol that adjusts autonomously the number of replicas to deliver a configured data availability guarantee. The protocol is based on a Distributed Hash Table (DHT), measurement of peer online probability in the syste...

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Choreography changes performed by one party may af- fect other parties. The changes and the implication for other parties can be determined. However, the required changes on the orchestration are difficult to determine since a chore- ography is an abstraction of the orchestration and thus in- formation is lost. In this paper an approach is proposed...

Although Web services are intended for short term, ad hoc collaborations, in practice many Web service compo- sitions are offered longterm to customers. While the Web services making up the composition may vary, the structure of the composition is rather fixed. For companies managing such Web service compositions, however, challenges arise which go...

Recently, a new generation of adaptive Process-Aware In-formation System (PAIS) has emerged, which enables dynamic service changes (i.e., changes of instances derived from a composite service and process respectively). This, in turn, results in a large number of pro-cess variants derived from the same process model, but differing in their structure...

Recently, a new generation of adaptive Process-Aware Infor-mation Systems (PAISs) has emerged, which enables structural process changes during runtime while preserving PAIS robustness and consis-tency. Such flexibility, in turn, leads to a large number of process variants derived from the same model, but differing in structure. Generally, such vari...

For various applications there is the need to compare the similarity between two process models. For example, given the as-is and to-be models of a particular business process, we would like to know how much they differ from each other and how we can efficiently transform the as-is to the to-be model; or given a running process instance and its ori...

In today's dynamic business world economic success of an enterprise increasingly depends on its ability to react to internal and external changes in a quick and ∞exible way. In response to this need, process-aware information systems (PAIS) emerged, which support the modeling, orchestration and monitoring of business processes. Recently, a new gene...

Recently, a new generation of adaptive Process-Aware Information Systems (PAIS) has emerged, which allows for dynamic process and service changes (e.g., to insert, delete, and move activities and service executions in a running process). This, in turn, has led to a large number of process variants derived from the same model, but differing in struc...

Recently, process-aware information systems (PAIS) were introduced, which allow for dynamic process and service changes. This, in turn, has led to a large number of process model variants, which are difficult to maintain and expensive to configure. This paper deals with goals and issues related to the mining of process model variants. Our overall g...

Data processing in environmental science is essential for doing science. The heterogeneity of data sources, data processing operations and infrastructures results in a lot of manual data and process integration work done by each scientist individually. This is very inefficient and time consuming. The aim is to provide a view based approach on acces...

In service oriented computing different techniques for monitoring service level agreements (SLAs) are available. Many of these monitoring approaches focus on bilateral agreements between partners. However, when monitoring composite services it is not only important to figure out whether SLAs are violated, but we also need to analyze why these viola...

Abstract To keep an overview on complex E-Commerce collabora- tions several models are used to describe them. When mod- els overlap in describing a collaboration, the overlapping information should not contradict. Models are of different nature and maintained by different people. Therefore, keep- ing model-overlap contradiction-free is challenging....

In today's dynamic business world economic success of an en-terprise increasingly depends on its ability to react to internal and exter-nal changes in a quick and flexible way. In response to this need, process-aware information systems (PAIS) emerged, which support the modeling, orchestration and monitoring of business processes and services respe...

In today's dynamic business world, success of an enterprise increasingly depends on its ability to react to changes in a quick and flexible way. In response to this need, process-aware information systems (PAIS) emerged, which support the modeling, orchestration and mon-itoring of business processes and services respectively. Recently, a new genera...

Environmental engineers from different organizations work in interdisciplinary projects having the need of information exchange. In particular, a collaborative environment with personalized access to information is needed, which supports strongly varying information needs of the users. This scenario is not fully supported by existing systems. For e...

Service-oriented architecture (SOA) is an evolving architectural paradigm where businesses can expose their capabilities as modular, network-accessible software services. By decomposing capabilities into modular services, organizations can share their offerings at multiple levels of granularity while also creating unique access points for their pee...

P2P data stores excel if availability of inserted data items must be guaranteed. Their inherent mechanisms to counter peer population dynamics make them suitable for a wide range of application domains. This paper presents and analyzes the split maintenance operation of our P2P data store. The operation aims at reorganizing replication groups in ca...

Development of composed services requires a continues adap- tation of the composed service to the changing environment of offered services. Services may no longer be available or may change performance characteristics, price, or quality of service criteria after they have been selected and used in a composition. The replacement of such a service re...

A lot of work exists on notions of equivalence and soundness relations of different workflow models, which are used in different domains like e.g. business process modeling, software and service engineering. These definitions are based on different models, including Petri nets and different versions of finite state automata, having different expres...

Collaborations among businesses can be described from different viewpoints. Two of these viewpoints are the value viewpoint, representing estimated values exchanged in a collaboration, and the coordination viewpoint, representing messages exchanged between the actors to coordinate the execution of a collaboration. To observe and maintain the value...

In this paper we propose a new approach for service-oriented enterprise application integration (EAI). Unlike current EAI solutions, which mainly focus on technological aspects, our approach allows business domain experts to get more involved in the integration process. First, we provide a technique for modeling application services at a sufficient...

Today, the term extended enterprise (EE) is typically meant to designate any collection of organizations sharing a common set of goals. In this broad sense, an enterprise can be a whole corporation, a government organization, or a network of geographically distributed entities. EE applications support digitalization of traditional business processe...

An extended enterprise (EE) can be described by a set of models each representing a specific aspect of the EE. Aspects can for example be the process flow or the value description. However, different models are done by different people, which may use different terminology, which prevents relating the models. Therefore, we propose a framework consis...

In information systems (IS) engineering different techniques for mod-eling inter-organizational collaborations are applied. In particular, value models estimate the profitability for involved stakeholders, whereas coordination mod-els are used to agree upon the inter-organizational processes before implementing them. During the execution of inter-o...

Development of composed services requires a continues adaptation of the composed service to the changing environment of offered services. Services may no longer be available or may change performance characteristics, price, or quality of service criteria after they have been selected and used in a composition. The replacement of such a service requ...

The research in the paper is motivated by building a decentralized/P2P XML storage on top of a DHT (Distributed Hash Table). The storage must provide high data availability and support updates. High data availability in a DHT can be guaranteed by data replication. However, DHTs can not provide a centralized coordination guaranteeing data consistenc...

An essential issue in peer-to-peer data management is to keep data highly available all the time. A common idea is to replicate data hoping that at least one replica is available when needed. However, due to churns, the number of created replicas could be not sufficient for guaranteeing the intended data availability. If the number of replicas is c...

Process-aware information systems have to be frequently adapted due to business process changes. One important challenge not adequately addressed so far concerns the evolution of process choreogra- phies, i.e., the change of interactions between partner processes in a cross-organizational setting. If respective modifications are applied in an uncon...

Service discovery of state dependent services has to take workflow as - pects into account. To increase the usability of a service discovery, the re sult list of services should be ordered with regard to the relevance of the services. Means of ordering a list of workflows due to their similarity with regard to a query ar e missing. In this paper di...

Inter-organizational business cooperations can be described from dif- ferent viewpoints each fulfilling a specific purpose. Since all viewpoints describe the same system they must not contradict each other, thus, must be consistent. Consistency can be checked based on common semantic concepts of the different viewpoints. This is sufficient for equa...

Self-managing or autonomic computing is a highly emerging field having been championed by industry and academia alike. Essentially the management of the system is being handed to the system itself, therefore the issue of trust in terms of the decisions the system makes regarding itself, is of paramount interest. This paper considers four aspects of...

Service discovery of state dependent services has to take workflow aspects into account. To increase the usability of a service discovery, the result list of services should be ordered with regard to the relevance of the services. Means of ordering a list of workflows due to their similarity with regard to a query are missing. This paper presents a...

Process-aware information systems have to be frequently adapted due to business process changes. One important challenge not adequately addressed so far concerns the evolution of process choreographies. If respective modifications are applied in an uncontrolled manner, inconsistencies or errors might occur in the sequel. In particular, modification...

Service oriented architectures facilitate loosely coupled composed services, which are established in a decentralized way. One challenge for such composed services is to guarantee consistency, i.e., deadlock-freeness. This paper presents a decentralized approach to consistency checking, which utilizes only bilateral views of the composed service ba...

Service discovery of state-dependent services has to take workflow a spects into account. To increase the usability of a query result, the results should b e ordered with regard to their relevance, that is, the similarity of the query and the resu lt list entry. Although there exist service discovery solutions considering workflow a spects, there i...

In today's businesses, there is a trend that service-oriented architecture (SOA) is evolving into a popular architectural paradigm for IT infrastructure. SOA allows companies' software systems to be shared as network-enabled electronic services with their commonly specified interfaces. Service discovery and composition are two emerging ones which a...

The existing service discovery infrastructure with UDDI as the de facto standard, is limited in that it does not sup- port more complex searching based on matching business processes. Two business processes match if they agree on their simple services, their processing order as well as any mandatory or optional requirements for the service. This ma...

This workshop is the result of joining the two workshops "Web Services Modeling and Implementation Using Sound Web Engineering Practices" (SMIWEP) and "Methods, Architectures & Technologies for e-Service Engineering" (MATeS), which were originally proposed in conjunction with the ICWE 2006 conference. As a result of the selection process of both wo...

The agility of an enterprise increasingly depends on its ability to dynamically set up new business processes or to modify existing ones, and to quickly adapt its information systems to these process changes. Companies are therefore developing a growing interest in concepts, technologies and systems that help them to flexibly align their businesses...

In today’s businesses, there is a trend that serviceoriented architecture (SOA) is evolving into a popular architectural paradigm for IT infrastructure. SOA allows companies’ software systems to be shared as networkenabled electronic services with their commonly specified interfaces. Service discovery and composition are two emerging ones which are...

There is an increasingly widespread acceptance of service-oriented architectures as a paradigm for integrating heterogeneous software applications. In this paradigm, independently developed and operated applications are exposed as (Web) services that are then interconnected using a set of standard protocols and languages. While the technology for d...

Multi-perspective approaches to analysis and design of businesses information systems are used to manage the complexity of the development process. A perspective contains a partial specification of the system from a particular stakeholder’s standpoint. This separation of concerns leads to potential inconsistencies between specifications from differ...

The control of actions performed by parties involved in a decentralized cross-organizational workflow is done by several independent workflow engines. Due to the lack of a centralized coordination control, an auditing is required which supports a reliable and secure detection of malicious actions performed by these parties. In this paper we identif...

Trust can be defined as to have confidence or faith in; a form of reliance or certainty based on past experience; to allow without fear; believe; hope: expect and wish; and extend credit to. The issue of trust in computing has always been a hot topic, especially notable with the proliferation of services over the Internet, which has brought the iss...