Thorsten Scheibler

Aggregation of Service Level Agreements in the Context of Business Processes

One can observe that more and more companies are focusing on their core compenetency and are outsourcing parts or even complete business processes to service providers. Service Level Agreements (SLAs) are used as a contractual basis to define certain non-functional properties (e.g. response time) a service has to provide. To determine the SLA of a business process a priori, the SLAs of the invoked services need to be aggregated into a single SLA for the business process. This paper defines a method how a service provider can aggregate the SLAs of the individual services within a business process into a single SLA. This provides a service provider with the capability to annotate the service that the business process implements with an appropriate SLA. We propose a framework that helps in carrying out the SLA aggregation within business processes. The framework consists of two parts: (i) a formal model for SLAs and (ii) a concept to aggregate SLAs, where algorithms can be plugged in.

EAI as a Service - Combining the Power of Executable EAI Patterns and SaaS

Enterprise Application Integration (EAI) problems are one of the major challenges IT departments are facing today. As enterprises merge, split up, or grow, existing legacy systems from different vendors implemented in different programming languages and running in different environments as well as roll-your-own applications have to be integrated. Furthermore, companies are starting to shift more and more on-premise software to software run in aSoftware as a Service (SaaS) business model. Outsourcing software to external and internal SaaS providers introduces new integration challenges, namely those of the integration of standard SaaS software with on-premise systems or other systems run at different SaaS providers which is a problem not addressed by SaaS platforms today. Recurring integration problems can be described by means of Enterprise Application Integration patterns. Those are used as nuggets of advice to solve complex integration problems. In this paper, we introduce executable EAI patterns offered in a SaaS business model to allow companies to focus on the integration without the need for the setup of complex integration infrastructures. Users will be guided by workflows customizing configurable EAI patterns to easily create integration solutions. We therefore propose EAI as a Service as a flexible, customizable, inexpensive way to tackle EAI problems both of on-premise systems but also of systems run in a SaaS business model.

A Framework for Executable Enterprise Application Integration Patterns

A great challenge for enterprises is the improvement of the utilization of their landscape of heterogeneous applications in complex EAI (Enterprise Application Integration) scenarios. Enterprise Application Integration Patterns help to address this challenge by describing recurring EAI problems and proposing possible solutions at an abstract level. However, EAI patterns are documentation only used by systems architects and developers to decide how to implement an integration solution. Thus, patterns do not specify how to produce the code that will actually implement the solution described by the pattern on a specific middleware. In this paper we introduce a framework that provides configuration capabilities for EAI patterns. The framework also allows to generate executable integration code from EAI patterns using a model-driven architecture approach. Furthermore, we present a tool providing this framework.

From Modelling to Execution of Enterprise Integration Scenarios: The GENIUS Tool

One of the predominant problems IT companies are facing today is Enterprise Application Integration (EAI). Most of the infrastructures built to tackle integration issues are proprietary because no standards exist for how to model, develop, and actually execute integration scenarios. EAI patterns gain importance for non-technical business users to ease and harmonize the development of EAI scenarios. These patterns describe recurring EAI challenges and propose possible solutions in an abstract way. Therefore, one can use those patterns to describe enterprise architectures in a technology neutral manner. However, patterns are documentation only used by developers and systems architects to decide how to implement an integration scenario manually. Thus, patterns are not theoretical thought to stand for artefacts that will immediately be executed. This paper presents a tool supporting a method how EAI patterns can be used to generate executable artefacts for various target platforms automatically using a model-driven development approach, hence turning patterns into something executable. Therefore, we introduce a continuous tool chain beginning at the design phase and ending in executing an integration solution in a completely automatically manner. For evaluation purposes we introduce a scenario demonstrating how the tool is utilized for modelling and actually executing an integration scenario.

A service-based approach for next-generation Product Lifecycle Management

Nowadays, one of the main challenges for companies is the effective management of IT-systems. In times where requirements and companies change steadily, the IT-infrastructure has to adopt these changes as well: new systems have to be integrated or existing adapted. Even worse, these systems work together to support business processes of a company and, thus, the infrastructures becomes complex and difficult to manage. The same situation is true for Product Lifecycle Management (PLM) that accompanies a product development by means of interconnected IT systems running on complex IT infrastructures. This paper introduces a viable solution to the integration of all phases of PLM. An Enterprise Service Bus (ESB) is employed as the service-based integration and communication infrastructure. Three exemplary scenarios are introduced to describe the benefits of using an ESB as compared to alternative PLM infrastructures. Furthermore, we introduce a service hierarchy to enable value-added services to enhance PLM functionality.

EMod: platform independent modelling, description and enactment of parameterisable EAI patterns

As enterprises merge, split up, or grow, existing legacy systems from different vendors implemented in different programming languages and running in different environments as well as roll-your-own applications have to be integrated. This fact is denoted as the Enterprise Application Integration (EAI) problem and is one of the major challenges IT departments are facing today. As a result of the need for operational flexibility and reuse, Service-Oriented Architectures (SOA) gain more and more importance as they allow for a flexible and standardised way to describe, reuse and integrate services in heterogeneous application landscapes. Enterprise Application Integration Patterns (EAI Patterns) are a means to describe integration problems using a set of patterns. The patterns therefore present nuggets of advice on how to solve complex recurring integration problems. In this paper we introduce a platform independent approach (EMod) to model, describe and enact EAI patterns in service-oriented architectures. We describe how EMod can be used to build stand-alone EAI solutions that integrate different applications in a Software as a Service (SaaS) environment. Furthermore we show how EMod can be used as a part of an application to integrate services into composite service-oriented applications. This is done by integrating EMod into the Service Component Architecture (SCA).

An EAI Pattern-Based Comparison of Spaces and Messaging

Enterprise application integration (EAI) <i>is</i> <i>a</i> <i>major</i> <i>challenge</i> <i>for</i> <i>enterprises</i> <i>to</i> <i>ensure</i> <i>optimal</i> <i>utilization</i> <i>of</i> <i>their</i> <i>landscape</i> <i>of</i> <i>diverse</i> <i>applications</i>. Enterprise application integration patterns help <i>to</i> <i>ease</i> <i>this</i> <i>problem</i> <i>by</i> <i>describing</i> <i>recurring</i> <i>EAI</i> <i>problems</i> <i>and</i> <i>proposing</i> <i>possible</i> <i>solutions.</i> <i>As</i> <i>of</i> <i>today</i>, message-oriented middleware (MOM) <i>is</i> <i>state-</i> <i>of-the-art</i> <i>for</i> <i>EAI</i> <i>integration</i> <i>middleware</i> <i>infrastructures.</i> <i>However</i>, space-based computing (SBC) <i>has</i> <i>been</i> <i>found</i> <i>to</i> <i>offer</i> <i>essentially</i> <i>the</i> <i>same</i> <i>qualities</i> <i>as</i> <i>MOM</i> <i>in</i> <i>terms</i> <i>of</i> <i>asynchronous,</i> <i>reliable</i> <i>and</i> <i>loosely</i> <i>coupled</i> <i>communication</i> <i>and</i> <i>might</i> <i>therefore</i> <i>provide</i> <i>a</i> <i>suitable</i> <i>alternative</i> <i>to</i> <i>MOM</i> <i>in</i> <i>the</i> <i>field</i> <i>of</i> <i>EAI.</i> <i>The</i> <i>objective</i> <i>of</i> <i>this</i> <i>paper</i> <i>is</i> <i>to</i> <i>provide</i> <i>a</i> <i>comparison</i> <i>of</i> <i>MOM</i> <i>and</i> <i>SBC</i> <i>from</i> <i>an</i> <i>applications</i> <i>point</i> <i>of</i> <i>view</i> <i>through</i> <i>an</i> <i>in-depth</i> <i>analysis</i> <i>of</i> <i>EAI</i> <i>patterns,</i> <i>assuming</i> <i>SBC</i> <i>instead</i> <i>of</i> <i>MOM</i> <i>as</i> <i>their</i> <i>underlying</i> <i>middleware</i>.

Service-based integration in event-driven manufacturing environments

Constantly changing business conditions require a high level of flexibility in business processes as well as an adaptive and fully interoperable IT infrastructure in todays manufacturing environments. The lack of flexibility prevents manufacturing companies to improve their responsiveness and to adapt their workflows to turbulent scenarios. In order to achieve highly flexible and adaptive workflows, information systems in digital factories and shop floors need to be integrated. The most challenging problem in such manufacturing environments is the high heterogeneity of the IT landscape, where the integration of legacy systems and information silos has lead to chaotic architectures over the last two decades. In order to overcome this issue, we present a flexible integration platform that allows a loose coupling of distributed services in event-driven manufacturing environments. Our approach enables a flexible communication between digital factory and shop floor components by introducing a service bus architecture. Our solution integrates an application-independent canonical message format for manufacturing events, content-based routing and transformation services as well as event processing workflows.

Executing Pipes-and-Filters with Workflows

In the context of Enterprise Application Integration individual tasks have typically been implemented using specialized EAI-vendor technology based on messaging, and quite often customer-specific implementations. Those implementations prominently exploit the Pipes-and-Filters architecture. This implementation approach is in conflict with the flow technology that is a cornerstone of the Service-Oriented Architecture for solving integration problems. In this paper, we present how this conflict can be resolved. Therefore, we first analyse the differences between Pipes-and-Filters architectures and workflow approaches in general, and present the advantages and drawbacks of each solution. Afterwards, we describe how integration solutions modelled based on the PaF architecture can be implemented using flow technology by transforming the appropriate PaF elements into appropriate workflow constructs. We then present the results of appropriate tests that show that the performance of the corresponding workflows is superior to the mapping of PaF patterns to message flows. We finish off with outlining the additional tangible and non-tangible benefits that the Workflow Management System provides, such as monitoring. In a nut shell, we illustrate that the PaF architecture does not require an own implementation, but can be converted into appropriate models to workflows for execution by an appropriate system.

Dynamic Message Routing Using Processes

The Enterprise Service Bus (ESB) is composable middleware that provides applications with services such as message routing and transformation, service composition, dynamic discovery, transactional support, coordination, security features, and others. In an ESB supporting SOAP message exchange, routing algorithms typically follow the sequential SOAP message processing model, where SOAP headers are the main artefacts used to specify the message route and the processing of the payload by intermediaries along that route. This model supports neither alternative nor parallel message routes. In the case of a failing intermediary node this leads to a failure in the message delivery. Moreover, the execution order of services on SOAP message payloads at the intermediaries cannot be prescribed. In this paper, we demonstrate how these deficiencies of the SOAP message processing model can be addressed. We introduce an approach that allows for specifying SOAP message routing logic in terms of BPEL processes. We show that parallel and alternative routes for SOAP messages can be modelled and executed, and the order of services that process a message at intermediaries can be predefined to accommodate the correct processing sequence as required by the concrete application domain. Features like dynamic discovery of services and flexible service composition are leveraged to enable flexible SOAP message routing.