On the standardisation of Web service management operations

Given the current interest in TCP/IP network management research towards Web services, it is important to recognise how standardisation can be achieved. This paper mainly focuses on the standardisation of operations and not management information. We state that standardisation should be done by standardising the abstract parts of a WSDL document, i.e. the interfaces and the messages. Operations can vary in granularity and parameter transparency, creating four extreme operation signatures, all of which have advantages and disadvantages

The role of the RM-ODP computational viewpoint concepts in the MDA approach

An MDA design approach should be able to accommodate designs at different levels of platform-independence. We have proposed a design approach previously (in [2]), which allows these levels to be identified. An important feature of this approach is the notion of abstract platform. An abstract platform is determined by the platform characteristics that are relevant for applications at a certain level of platform-independence, and must be established by considering various design goals. In this paper, we define a framework that makes it possible to use RM-ODP concepts in our MDA design approach. This framework allows a recursive application of the computational viewpoint at different levels of platform-independence. This is obtained by equating the RM-ODP notion of infrastructure to our notion of abstract platform

Defining and Prototyping a Life-cycle for Dynamic Service Composition

Since the Internet has become a commodity in both wired and wireless environments, new applications and paradigms have emerged to explore this highly distributed and widespread system. One such paradigm is service-orientation, which enables the provision of software functionality as services, \ud allowing in this way the construction of distributed systems with loosely coupled parts. The Service-Oriented Architecture (SOA) provides a set of principles to create service-oriented systems, by defining how services can be \ud created, composed, published, discovered and invoked. In accordance with these principles, in this paper we address the challenge of performing dynamic service composition. The composition process and its associated tasks have to be precisely defined so that the different problems of dynamic service composition can be identified and tackled. To achieve this, this paper defines a life-cycle for dynamic service composition, which defines the required phases and stakeholders. Furthermore, we present our prototype in which the different phases of the dynamic service composition life-cycle are being implemented. This prototype is being used to experiment with and validate our initial ideas on dynamic service composition

Using P3P in a web services-based context-aware application platform

This paper describes a proposal for a privacy control architecture to be applied in the WASP project. The WASP project aims to develop a context-aware service platform on top of 3G networks, using web services technology. The proposed privacy control architecture is based on the P3P privacy policy description standard defined by W3C. The paper identifies extensions to P3P and its associated preference expression language APPEL that are needed to operate in a context-aware environment

A model-based approach to service creation

This paper presents a model-based approach to support service creation. In this approach, services are assumed to be created from (available) software components. The creation process may involve multiple design steps in which the requested service is repeatedly decomposed into more detailed functional parts, until these parts can be mapped onto software components. A modelling language is used to express and enable analysis of the resulting designs, in particular the behaviour aspects. Methods are needed to verify the correctness of each design step. A technique called behaviour refinement is introduced to assess the conformance relation between an abstract behaviour and a more concrete (detailed) behaviour. This technique is based on the application of abstraction rules to determine the abstraction of the concrete behaviour such that the obtained abstraction can be compared to the original abstract behaviour. The application of this refinement technique throughout the creation process enforces the correctness of the created servic

Towards a flexible service integration through separation of business rules

Driven by dynamic market demands, enterprises are continuously exploring collaborations with others to add value to their services and seize new market opportunities. Achieving enterprise collaboration is facilitated by Enterprise Application Integration and Business-to-Business approaches that employ architectural paradigms like Service Oriented Architecture and incorporate technological advancements in networking and computing. However, flexibility remains a major challenge related to enterprise collaboration. How can changes in demands and opportunities be reflected in collaboration solutions with minimum time and effort and with maximum reuse of existing applications? This paper proposes an approach towards a more flexible integration of enterprise applications in the context of service mediation. We achieve this by combining goal-based, model-driven and serviceoriented approaches. In particular, we pay special attention to the separation of business rules from the business process of the integration solution. Specifying the requirements as goal models, we separate those parts which are more likely to evolve over time in terms of business rules. These business rules are then made executable by exposing them as Web services and incorporating them into the design of the business process.\ud Thus, should the business rules change, the business process remains unaffected. Finally, this paper also provides an evaluation of the flexibility of our solution in relation to the current work in business process flexibility research

Consistency in Multi-Viewpoint Architectural Design of Enterprise Information Systems

Different stakeholders in the design of an enterprise information system have their own view on that design. To help produce a coherent design this paper presents a framework that aids in specifying relations between such views. To help produce a consistent design the framework also aids in specifying consistency rules that apply to the view relations and in checking the consistency according to those rules. The framework focuses on the higher levels of abstraction in a design, we refer to design at those levels of abstraction as architectural design. The highest level of abstraction that we consider is that of business process design and the lowest level is that of software component design. The contribution of our framework is that it provides a collection of basic concepts that is common to viewpoints in the area of enterprise information systems. These basic concepts aid in relating viewpoints by providing: (i) a common terminology that helps stakeholders to understand each others concepts; and (ii) a basis for defining re-usable consistency rules. In particular we define re-usable rules to check consistency between behavioural views that overlap or are a refinement of each other. We also present an architecture for a tool suite that supports our framework. We show that our framework can be applied, by performing a case study in which we specify the relations and consistency rules between the RM-ODP enterprise, computational and information viewpoints

Monitoring of distributed component interactions

We have describe a generic monitoring approach that can be used to enhance the quality of distributed component software. The generality of the approach is achieved through using reflective technology, i.e. CORBA Interceptors, CORBA POA and Java 2 features. A drawback of using interceptors is the fact that their interfaces have not been standardised so far. However, the process of standardisation is ongoing and has recently resulted in an OMG Joint Revised Submission called Portable Interceptors. Although the Java 2 API enables discovery of ‘forks’ in the execution, we find it lacking functionality for the purpose of discovering synchronisation points (e.g., ‘joins’) within multithreaded components