Abstract—Mixed service-oriented systems composed of human actors and software services build up complex interaction networks. Without any coordination, such system may exhibit undesirable properties due to unexpected behavior. Also, communications and interactions in such networks are not preplanned by top-down composition models. Consequently, the management of service-oriented applications is difficult due to changing interaction and behavior patterns that possibly contradict and result in faults from varying conditions and misbehavior in the network. In this paper we present a self-adaptation approach that regulates local interactions to maintain desired system functionality. To prevent degraded or stalled systems, adaptations operate by link modification or substitution of actors based on similarity and trust metrics. Unlike a security perspective on trust, we focus on the notion of socially inspired trust. We design an architecture based on two separate independent frameworks. One providing a real Web service testbed extensible for dynamic adaptation actions. The other is our self-adaptation framework including all modules required by systems with self- * properties. In our experiments we study a trust and similarity based adaptation approach by simulating dynamic interactions in the real Web services testbed. Index Terms—Service-oriented collaboration, monitoring, selfadaptation, web service testbed, dynamic trust

Web services and service-oriented architecture (SOA) have become the de facto standard for designing distributed and loosely coupled applications. Many service-based applications demand for a mix of interactions between humans and Software-Based Services (SBS). An example is a process model comprising SBS and services provided by human actors. Such applications are difficult to manage due to changing interaction patterns, behavior, and faults resulting from varying conditions in the environment. To address these complexities, we introduce a self-healing approach enabling recovery mechanisms to avoid degraded or stalled systems. The presented work extends the notion of self-healing by consideringamixtureof human and service interactions observing their behavior patterns. We present the design and architecture of the VieCure framework supporting fundamental principles for autonomic self-healing strategies. We validate our self-healing approach through simulations.

During the previous years, we presented several results concerned with various issues related to the correctness of models for business processes and services (i. e., interorganizational business processes). For most of the results, we presented tools and experimental evidence for the computational capabilities of our approaches. Over the time, the implementations grew to a consistent and interoperable family of tools, which we call service-technology.org. This paper aims at presenting this tool family service-technology.org as a whole. We briefly sketch the underlying formalisms and covered problem settings and describe the functionality of the participating tools. Furthermore, we discuss several lessons that we learned from the development and use of this tool family. We believe that the lessons are interesting for other academic tool development.

Abstract. When developing an existing service further, new functionalities can be added or existing functionalities can be changed or removed. Consequently, also test cases have to be added to or removed from the existing test suite. In this paper, we present an idea how a test suite can be adjusted to these changes. Thereby, we focus on modifications concerning the communication behavior of a service. 1

Abstract. A request to a service registry must be answered with a service that fits in several regards, including semantic compatibility, non-functional compatibility, and interface compatibility. In the case of stateful services, there is the additional need to check behavioral (i.e. protocol) compatibility. This paper is concerned with the latter aspect. An apparent approach to establishing behavioral compatibility would be to apply the well-known technology of model checking to a composition of the provided service and the requesting service. However, this procedure must potentially be repeated for all provided services in the registry which may unprohibitively slow down the response time of the broker. Hence, we propose to insert a preprocessing step. It consists of computing an abstraction of the behavior for each published service that we call communication fingerprint. Upon request, we use the fingerprint to rule out as many as possible incompatible services thus reducing the number of candidates that need to be model checked for behavioral compatibility. The technique is based on linear programming and is thus extremely efficient. We validate our approach on a large set of services that we cut out of real world business processes. 1

Abstract—Web services and service-oriented architecture (SOA) have become the de facto standard for designing distributed and loosely coupled applications. Many servicebased applications demand for a mix of interactions between humans and Software-Based Services (SBS). An example is a process model comprising SBS and services provided by human actors. Such applications are difficult to manage due to changing interaction patterns, behavior, and faults resulting from varying conditions in the environment. To address these complexities, we introduce a self-healing approach enabling recovery mechanisms to avoid degraded or stalled systems. The presented work extends the notion of self-healing by consideringamixtureof human and service interactions observing their behavior patterns. We present the design and architecture of the VieCure framework supporting fundamental principles for autonomic self-healing strategies. We validate our self-healing approach through simulations. Keywords-Self-healing model, monitoring, recovery, mixed service-oriented system, delegation behavior I.