Cindy Michiels

Consistency by Construction: The Case of MERODE

Modeling languages such as UML offer a set of basic models to describe a software system from different views and at different levels of abstraction. Tools supporting an unrestricted usage of these UML models cannot guarantee the consistency between multiple models/views, due to the lack of a formal definition of the semantics of UML diagrams. A better alternative that does allow for automatic consistency checking is modeling according to the single model principle. This approach is based on the conception of a single model, for which different views are constructed, and with an automatic or semi-automatic generation or consistency checking among these views. Three basic approaches to consistency checking are consistency by analysis, consistency by monitoring and consistency by construction. In this paper we illustrate the consistency by construction approach by means of the conceptual domain modeling approach MERODE and its associated case-tool MERMAID. We also illustrate how consistency by construction improves the validity and completeness of the conceptual model.

An event based approach to web service design and interaction

This paper advocates an approach to web service design and interaction that is based on web services simultaneously participating in shared business events. In contrast to one-to-one method invocations, such events are broadcast in parallel to all web services that participate in it. Moreover, the transactional business events are distinguished from non-transactional attribute inspections. The paper first discusses the role of the business event concept as the cornerstone for a methodical analysis and design phase. Then, it is shown how the event broadcasting paradigm can be implemented by means of SOAP messaging.

Domain Modelling and the Co-Design of Business Rules in the Telecommunication Business Area

This paper discusses the development of an enterprise domain model in an environment where part of the domain knowledge is vague and not yet formalised in company-wide business rules. The domain model was developed for a young company starting in the telecommunications sector. The company relied on a number of stand-alone business support systems and sought for a manner to integrate them. There was opted for the development of an enterprise-wide domain model that had to serve as an integration layer to coordinate the stand-alone applications. A specific feature of the company was that it could build up its information infrastructure form scratch, so that many aspects of its business were still in the process of being defined. The paper will highlight parts of the Enterprise Model where there was a need for co-designing business rules together with the domain model. A result of this whole effort was that the company got more insight into important domain knowledge and developed a common understanding across functional areas of the way of doing business.

Event Based Web Service Description and Coordination

This paper proposes the concept of business events as the cornerstone to web service description and coordination. First, a web service architecture is introduced as the result of an event based analysis & design phase. Then, it is advocated how the event concept can be used for semantically rich web service description. A distinction is made between two web service interfaces: a non-transactional query interface and a transactional event notification interface. Furthermore, a web service composition model is proposed, based on event broadcasting and event preconditions, instead of traditional one-to-one method invocations. The composition model is presented in a static variant and in a version with dynamic subscription. Throughout the paper, it is shown how the event based approach fits entirely within the current standard SOAP/WSDL/UDDI web services stack.

An enterprise layer‐based approach to application service integration

At present, many companies rely on third‐party applications and application services for (part of) their information systems. When applications from different parties are used together, an integration problem arises. This paper describes an integration approach based on the construction of an enterprise layer. This approach is deliberately kept away from a document‐based, flow‐oriented approach, where business processes are hard coded into the application architecture. Interaction is based on the concurrent update of a shared underlying enterprise layer. At the same time, the application architecture becomes easily adaptable to re‐engineered business processes.

A Layered Architecture Sustaining Model Driven and Event Driven Software Development

This paper presents a layered software architecture reconciling model-driven, event-driven, and object-oriented software development. In its simplest form, the architecture consists of two layers: an enterprise layer consisting of a relatively stable business model and an information system layer, containing the more volatile user functionality. The paper explains how the concept of events is used in the enterprise layer as a means to make business objects more independent of each other. This results in an event handling sublayer, allowing to define groups of events and handling consistency and transaction management aspects. This type of architecture results in information systems with a high-level modular structure, where changes are easier to perform as higher layers will not influence the inherently more stable lower layers.