Joachim Schelp

Although companies introduced enterprise application integration (EAI) a couple of years ago, the complexity of corporate application landscapes is ever increasing. The current wave of technology being introduced into these application landscapes are service oriented architectures (SOA). Not unlike EAI before the introduction of these technologies is associated with re-use of software components and reaping cost cutting potentials. But when looking at the still increasing complexity of application landscapes following the introduction of SOA, the re-use and cost cutting arguments lead to disappointment. However, SOA offers a great potential to increase corporate agility. In order to gain and preserve corporate agility it is necessary to explicitly manage enterprise architecture. This paper discusses the problems of re-use and cost cutting expectations in SOA and contrasts them with the potentials related to make sustainable contributions to corporate agility. Structures, processes, and instruments to realize these potentials are discussed with reference to a literature review as well as to selected case studies.

The ever growing complexity of information system (IS) landscapes is a transparency and simplification challenge by its own. When business requirements frequently change or when technical innovations are frequently implemented, IS agility has to be aimed at in addition to transparency and simplicity. Service orientation claims to support agility. An integrated methodology to service construction is needed which is based on an appropriate enterprise architecture framework, and which reflects the different life cycles on the various architectural layers. As a contribution towards service construction methodology, this paper compares enterprise service construction with the construction of conventional business applications in order to assess the (re-)usability of business application construction techniques for enterprise service construction. Based on an analysis of traditional business application design techniques, hypotheses for the design of enterprise services are developed. Five case studies are presented and analyzed which represent enterprise service design practices in large companies with heterogeneous IS landscapes. On the one hand, there is evidence that enterprise services are designed along the same guidelines which proved useful for traditional application development. On the other hand, there are indicators that the specific properties of enterprise services lead to adjusted design guidelines.

Service oriented (re-)design aims at increasing the flexibility of application architecture. In contrast to traditional application design, functionality clusters are intended to be coarse-grained and loosely coupled. The question is whether this new design paradigm also leads to different types of applications: In traditional application design, applications either are integrated along organizational structure (process oriented), along information objects (information oriented), or according to certain reusable functionalities (functionality / channel oriented). In practice, corresponding enterprise service types can be observed. While information oriented and functionality / channel enterprise services are designed widely similar to their traditional application counterparts, process oriented enterprise services usually have higher granularity. Based on four case analyses, this paper presents design approaches, analyzes enterprise service design and compares enterprise service design to traditional application design. Since both design paradigms seem to lead to widely similar architectures, potential reasons are discussed.

The value returned by Enterprise Architecture (EA) is being viewed with increasing consideration by researchers and practitioners. They struggle to justify the EA investments made. Quantifying the Enterprise Architecture benefits has always been a challenge because measurements and real value delivered can not often be expressed in simple technical oriented metrics only.In this paper we suggest a multi-perspective framework, based on the concept of Balanced Scorecard (BSC), for providing guidance about where to identify and quantify the value of EA from the perspective of management. A derived methodology is used to localize a few selected Key Performance Indicators (KPI's) for measuring the benefits of Enterprise Architecture that help practitioners to design and implement the suggested framework.

In this paper success factors for application integration are identified. Furthermore, the factors are confirmed using structural equation modeling. Success is measured using five goal indicators: quality of process support, business satisfaction, application integration costs, architectural flexibility and time-to-market. All factors discussed — architecture management, business-IT alignment, organization of integration, integration methodology, service oriented architecture, consolidation of applications, standardization and technical quality of integration infrastructures — show positive impact on application integration success. Since no dominant factor could be identified, a balanced implementation of all success factors is recommended.