Non-desynchronizable service choreographies

A precise definition of interaction behavior between services is a prerequisite for successful business-to-business integration. Service choreographies provide a view on message exchanges and their ordering constraints from a global perspective. Assuming message sending and receiving as one atomic step allows to reduce the modelers’ effort. As downside, problematic race conditions resulting in deadlocks might appear when realizing the choreography using services that exchange messages asynchronously. This paper presents typical issues when desynchronizing service choreographies. Solutions from practice are discussed and a formal approach based on Petri nets is introduced for identifying desynchronizable choreographies.

The rise of web service ecosystems

The convergence of Internet marketplaces and service-oriented architectures has spurred the growth of Web service ecosystems. This paper articulates a vision for Web service ecosystems, discusses early manifestations of this vision, and presents a unifying architecture to support the emergence of larger and more sophisticated ecosystems

An introduction to service choreographies (Servicechoreographien – eine Einführung)

Service oriented architecture (SOA) is an architectural style for building software systems based on services. Especially in those scenarios where services implement business processes, complex conversations between the services occur. Service choreographies are a means to capture all interaction obligations and constraints from a global perspective. This article introduces choreographies as an important artifact for SOA, compares them to service orchestrations and surveys existing languages for modeling them.

SOA for business networks - service delivery framework

The next generation of SOA needs to scale for flexible service consumption, beyond organizational boundaries and current B2B applications, into communities, eco-systems, and business networks. In the wider and, ultimately, global settings, new capabilities are needed so that business partners can efficiently and reliably enable, adapt, and expose services where they can be discovered, ordered, consumed, metered, and paid for, through new applications and opportunities, driven by third parties in the global "village". This trend is already underway, in different ways, through various early adopter market segments. For the small medium enterprises segment, Google, Intuit-Microsoft, and others have launched appstores, through which an open-ended array of hosted applications are sourced from the development community and procured as maketplace commondities. In the corporate sector, the marketplace model and business network hubs are being put in place on top of connectivity and network orchestration investments for capitalizing services as tradable assets, seen in banking/finance (e.g. American Express Intelligent Marketplace), logistics (e.g., the E2open hub), and the public sector (e.g., UK DirectGov whole-of-government citizen services delivery).

A requirements framework for semantic business process modelling

The emergence of semantic technologies to deal with the underlying meaning of things, instead of a purely syntactical representation, has led to new developments in various fields, including business process modeling. Inspired by artificial intelligence research, technologies for semantic Web services have been proposed and extended to process modeling. However, the applicablility of semantic Web services for semantic business processes is limited because business processes encompass wider requirements of business than Web services. In particular, processes are concerned with the composition of tasks, that is, in which order activities are carried out, regardless of their implementation details; resources assigned to carry out tasks, such as machinery, people, and goods; data exchange; and security and compliance concerns.

Isotactics as a foundation for alignment and abstraction of behavioral models

There are many use cases in business process management that require the comparison of behavioral models. For instance, verifying equivalence is the basis for assessing whether a technical workflow correctly implements a business process, or whether a process realization conforms to a reference process. This paper proposes an equivalence relation for models that describe behaviors based on the concurrency semantics of net theory and for which an alignment relation has been defined. This equivalence, called isotactics, preserves the level of concurrency of aligned operations. Furthermore, we elaborate on the conditions under which an alignment relation can be classified as an abstraction. Finally, we show that alignment relations induced by structural refinements of behavioral models are indeed behavioral abstractions.

A unified description language for human to automated services

Through the rise of cloud computing, on-demand applications, and business networks, services are increasingly being exposed and delivered on the Internet and through mobile communications. So far, services have mainly been described through technical interface descriptions. The description of business details, such as pricing, service-level, or licensing, has been neglected and is therefore hard to automatically process by service consumers. Also, third-party intermediaries, such as brokers, cloud providers, or channel partners, are interested in the business details in order to extend services and their delivery and, thus, further monetize services. In this paper, the constructivist design of the UnifiedServiceDescriptionLanguage (USDL), aimed at describing services across the human-to-automation continuum, is presented. The proposal of USDL follows well-defined requirements which are expressed against a common service discourse and synthesized from currently available servicedescription efforts. USDL's concepts and modules are evaluated for their support of the different requirements and use cases.

Handbook of service description

With the growth in number and sophistication of services widely available, there is a new urgency for comprehensive service descriptions that take into account both technical and business aspects. The last years have seen a number of efforts for best-of-breed service description focusing on specific aspects of services. The Handbook of Service Description provides the most advanced state of the art insights into these. The main parts of the book provide the most detailed documentation of the Unified Service Description Language (USDL) to date. USDL has been developed across several research institutes and publicly funded projects across Europe and Australia, currently extending to the Americas as part of a standardization push through W3C. The scope of services extends across IT and business, i.e., the socio-technical sense of services scaled to business networks. In this respect, purely human, purely automated and mixed human/automated services were considered, that have a boundary of cognizance that is available through the tasks of service provisioning, discovery, access and delivery. Taken together, the Handbook of Service Description provides a comprehensive reference suitable for a wide-reaching audience including researchers, practitioners, managers, and students who aspire to learn about or to create a deeper scientific foundation for service description and its methodological aspects.

The internet of services and USDL

A prominent research focus, especially in the context of EU public funding, has been the systematic use of the Internet for new ways of value creation in the services sector. This idea of service networks in the Internet, frequently dubbed the Internet of Services or Web service ecosystems, wants to make services tradable in digital media. In order to enable communication and trade between providers and consumers of services, the Internet of Services requires a standard that creates a "commercial envelope" around a service. This is where the Unified Service Description Language (USDL) comes into play as a normative and balanced unification of service information. The unified description established by USDL is machine-processable, considers technical and business aspects of a service as well as functional and non-functional attributes.

Representing USDL for humans and tools

This chapter deals with technical aspects of how USDL service descriptions can be read from and written to different representations for use by humans and tools. A combination of techniques for representing and exchanging USDL have been drawn from Model-Driven Engineering and Semantic Web technologies. The USDL language's structural definition is specified as a MOF meta-model, but some modules were originally defined using the OWL language from the Semantic Web community and translated to the meta-model format. We begin with the important topic of serializing USDL descriptions into XML, so that they can be exchanged beween editors, repositories, and other tools. The following topic is how USDL can be made available through the Semantic Web as a network of linked data, connected via URIs. Finally, consideration is given to human-readable representations of USDL descriptions, and how they can be generated, in large part, from the contents of a stored USDL model.

Enabling USDL by tools

Fundamental tooling is required in order to apply USDL in practical settings. This chapter discusses three fundamental types of tools for USDL. First, USDL editors have been developed for expert and casual users, respectively. Second, several USDL repositories have been built to allow editors accessing and storing USDL descriptions. Third, our generic USDL marketplace allows providers to describe their services once and potentially trade them anywhere. In addition, the iosyncrasies of service trading as opposed to the simpler case of product trading. The chapter also presents several deployment scenarios of such tools to foster individual value chains and support new business models across organizational boundaries. We close the chapter with an application of USDL in the context of service engineering.

SOA approaches

As the service-oriented architecture paradigm has become ever more popular, different standardization efforts have been proposed by various consortia to enable interaction among heterongeneous environments through this paradigm. This chapter will overview the most prevalent of these SOA approaches. It will first show how technical services can be described, how they can interact with each other and be discovered by users. Next, the chapter will present different standards to facilitate service composition and to design service-oriented environments in light of a universal understanding of service orientation. The chapter will conclude with a summary and a discussion on the limitations of the reviewed standards along their ability to describe service properties. This paves the way to the next chapters where the USDL standard will be presented, which aims to lift such limitations.

Design overview of USDL

Enabling web-based service networks and ecosystems requires a way of describing services by a "commercial envelope" as discussed in Chapter 1. A uniform conception of services across all walks of life (including technical services) is required capturing business, operational and technical aspects. Therefore, our proposed Unified Service Description Language (USDL) particularly draws from and generalizes the best-of-breed approaches presented in Part I. The following chapter presents the design rationale of USDL where the different aspects are put in a framework of descriptions requirements. This is followed by the subsequent chapters of this part that provide details on specific aspects such as pricing or legal issues.

Interactive product browsing and configuration using remote augmented reality sales services

Real-time remote sales assistance is an underdeveloped component of online sales services. Solutions involving web page text chat, telephony and video support prove problematic when seeking to remotely guide customers in their sales processes, especially with configurations of physically complex artefacts. Recently, there has been great interest in the application of virtual worlds and augmented reality to create synthetic environments for remote sales of physical artefacts. However, there is a lack of analysis and development of appropriate software services to support these processes. We extend our previous work with the detailed design of configuration context services to support the management of an interactive sales session using augmented reality. We detail the context and configuration services required, presenting a novel data service streaming configuration information to the vendor for business analytics. We expect that a fully implemented configuration management service, based on our design, will improve the remote sales experience for both customers and vendors alike via analysis of the streamed information.

Analysis of multilateral service conversations in global business networks

The rapid growth of services available on the Internet and exploited through ever globalizing business networks poses new challenges for service interoperability. New services, from consumer “apps”, enterprise suites, platform and infrastructure resources, are vying for demand with quickly evolving and overlapping capabilities, and shorter cycles of extending service access from user interfaces to software interfaces. Services, drawn from a wider global setting, are subject to greater change and heterogeneity, demanding new requirements for structural and behavioral interface adaptation. In this paper, we analyze service interoperability scenarios in global business networks, and propose new patterns for service interactions, above those proposed over the last 10 years through the development of Web service standards and process choreography languages. By contrast, we reduce assumptions of design-time knowledge required to adapt services, giving way to run-time mismatch resolutions, extend the focus from bilateral to multilateral messaging interactions, and propose declarative ways in which services and interactions take part in long-running conversations via the explicit use of state.