Three applications of aspect technology

Abstract

The emergence of converged services is driving communication service providers to cut back on software engineering costs, shorten time-to-market and build personalisable services. As illustrated by BT’s 21CN architecture initiative, the industry is responding with the vision of next-generation service delivery platforms (SDPs). The move towards SDPs demands a principled approach to achieve reuse, modularity, and evolvability of software artefacts, ranging from business processes to application components. To this end, new proposals, such as generative programming, aspect-oriented programming, and model-driven engineering, are put forward to complement traditional object-oriented and component programming paradigms. Aspect-oriented programming — the focus of this paper — endorses the principle of separation of concerns. Originally devoted to the modularisation of crosscutting concerns (e.g. synchronisation, security, debugging, monitoring), it has grown from an aspect-oriented extension to Java (AspectJ) into a general approach for the development of adaptive software artefacts. The purpose of this paper is to introduce aspect technology and demonstrate its versatility across three different application domains. Specifically, we present an aspect-based extension to a process execution language (BPEL) for developing adaptable workflows, an AspectJ-based instrumentation of a field resource scheduling system, and a proposal to customise mobile services using aspects. While the technology is still maturing, we hope this paper will raise the level of awareness on the potential of aspects across BT.