Oliver Holschke

Introducing Preferences over NFPs into Service Selection in SOA

When implementing a business or software activity in SOA, a match is sought between the required functionality and that provided by a web service. In selecting services to perform a certain business functionality, often only hard constraints are considered. However, client requirements over QoS or other NFP types are often soft and allow tradeoffs. We use a graphical language for specifying hard constraints, preferences and tradeoffs over NFPs as well as service level objectives (SLO). In particular, we use the TCP and UCP network formalisms to allow for a simple yet very flexible specification of hard constraints, preferences, and tradeoffs over these properties. Algorithms for selecting web services according to the hard constraints, as well as for optimizing the selected web service configuration, according to the specification, were developed.

Granularity as a Cognitive Factor in the Effectiveness of Business Process Model Reuse

Reusing design models is an attractive approach in business process modeling as modeling efficiency and quality of design outcomes may be significantly improved. However, reusing conceptual models is not a cost-free effort, but has to be carefully designed. While factors such as psychological anchoring and task-adequacy in reuse-based modeling tasks have been investigated, information granularity as a cognitive concept has not been at the center of empirical research yet. We hypothesize that business process granularity as a factor in design tasks under reuse has a significant impact on the effectiveness of resulting business process models. We test our hypothesis in a comparative study employing high and low granularities. The reusable processes provided were taken from widely accessible reference models for the telecommunication industry (enhanced Telecom Operations Map). First experimental results show that Recall in tasks involving coarser granularity is lower than in cases of finer granularity. These findings suggest that decision makers in business process management should be considerate with regard to the implementation of reuse mechanisms of different granularities. We realize that due to our small sample size results are not statistically significant, but this preliminary run shows that it is ready for running on a larger scale.

Impact of granularity on adjustment behavior in adaptive reuse of business process models

Business process diagrams as exteriorized forms of distributed organizational knowledge can be valuable assets when shared and reused in similar process design tasks. However, little empirical research has been conducted to shed light on the cognitive processes involved during the adaptation of retrieved process models. We hypothesize that model granularity has significant effects on human adjustment behavior irrespective of the editing distances between reuse and solution models. The results of our laboratory experiment, which is dimensioned according to real-world cases, contribute to a more specific classification of adaptation operations and their cognitive efforts, and refine the notion of process similarity. This study follows up on our former research work by amending minor flaws in the experiment setup; it now provides a comprehensive analytical apparatus for further replicated tests as the predictive power of our explorative study, regarding e.g. varied business contexts and task dimensions, remains limited.

Using Enterprise Architecture Models and Bayesian Belief Networks for Failure Impact Analysis

The increasing complexity of enterprise information systems makes it very difficult to prevent local failures from causing ripple effects with serious repercussions to other systems. This paper proposes the use of Enterprise Architecture models coupled with Bayesian Belief Networks to facilitate Failure Impact Analysis. By extending the Enterprise Architecture models with the Bayesian Belief Networks we are able to show not only the architectural components and their interconnections but also the causal influence the availabilities of the architectural elements have on each other. Furthermore, by using the Diagnosis algorithm implemented in the Bayesian Belief Network tool GeNIe, we are able to use the network as a Decision Support System and rank architectural components with their respect to criticality for the functioning of a business process. An example featuring a car rental agency demonstrates the approach.

Extracting business logic from business process models

Business rules and business process management (BPM) are increasingly considered as complements towards the quest of better business process insight and control by researchers and practitioners. The important role of business rules in BPM is now widely accepted among application software producers, researchers and business process managers. This development resulted in extensive process maps created by many enterprises. Increasingly needed tool support for business rules management and modeling became a relevant element at the market of business application software. Although systems and organizational units involved in the business process were captured in process diagrams, business rules that govern them were often not explicitly included in the models. This paper suggests an extraction process for business rules identification from business process models. Applying this process introduces a structured approach and management aspects within rules discovery by focusing on rule sources that are important for the process goal and providing a rule structure.

Enhancing Semantic Service Discovery in Heterogeneous Environments

The advent of service-oriented architectures promises companies efficient and effective support of their business processes. Discovery of services with appropriate functionality may be supported by enhancing the syntactical information using additional semantics. However, services of different providers are generally described with heterogeneous concepts. This paper investigates how heterogeneity during service discovery may be overcome using automatic similarity computation. A suitable approach is introduced and a prototype demonstrates that a reliable alignment tool increases overall quality of service discovery.

Platform-as-a-Service for business customers

Telecommunication providers are still searching for business models beyond the bit pipe. While added-value services like Software-as-a-Service (SaaS) become more and more common for private customers as well as small and medium enterprises, in this paper we demonstrate the opportunities of Platform-as-a-Service offerings for specific business domains. By offering such platforms as cloud services, telecommunication providers can leverage their existing communications infrastructure to provide added-value services. Customer-specific SaaS can be created rapidly on such platforms, enabling customized business applications on a rental pricing scheme.

IT Consolidation: An Optimization Approach

Consolidation of IT resources is a frequently cited task for IT decision makers, aiming to remove redundancy and thereby to cut costs. However, while economically motivated, the methods described in the literature rarely address costs directly. Instead, the focus often remains on purely IT-related considerations. In this paper, IT consolidation is addressed fro man operations research perspective, applying a binary integer programming model to find optimal solutions to consolidation problems. Since accurate cost estimates are vital to successful consolidation, and play an important role in the presented binary integer program, the paper also addresses the costs involved in consolidation, with a particular focus on the costs of modifying business processes. Applying the mathematical method, with accurate cost estimates, enables decision makers to make optimal decisions in a transparent and rigorous way. The use of the proposed method is demonstrated with an example based on a real consolidation problem from a large European power supplier.

Towards a Method for Service Design

Services are the vital part of a service-oriented architecture. Their development and design are essential parts of the development and implementation of a service-oriented architecture. Thus, numerous approaches in research and practice exist that refer to different aspects of service design. These are focused on specific needs or aspects in service design. According to the literature review provided in this paper, no single service design approach covers all the aspects that are needed for the implementation and deployment of a service-oriented architecture. Beside the literature review this paper provides a service design approach that combines the existing methods and approaches. The goal is its further development towards a service design method for service design in research and industry.

Flexible Softwareänderung in Platform-as-a-Service-Angeboten

ZusammenfassungEin bisher unerreichtes Ziel der entwicklung betrieblicher Softwaresysteme ist die angleichung von it und Organisation. Die aufkommenden Platform-as-a-Service-Angebote (PaaS) bieten das Potenzial, diesem Ziel näher zu kommen. Neben den technischen Herausforderungen müssen jedoch auch die Softwareentwicklungsmethoden den neuen Gegebenheiten angepasst werden. Erst dadurch lassen sich Flexibilität und Effizienz in der Softwareentwicklung signifikant steigern. Der Artikel stellt eine solche Methode basierend auf einer modernen Prozessplattform vor. Anhand von simulierten Softwareänderungen in einem realen Szenario zeigen wir die Vorteile der neuen Methode gegenüber der klassischen komponentenbasierten Entwicklung. Unser Ziel ist es, dadurch den Graben zwischen Business und IT weiter zu schließen.