Methodologies for Design of Service-Based Systems - Intentional Perspectives on Information Systems Engineering - page 302

Adaptivity at the software service level is being studied within the S-Cube 1
(Software Services and Systems) European network of excellence, with the goal
of developing advanced design tools and run-time modules which support adaptiv-
ity. Service-oriented design has to take into account the fact that software services
are strictly related to real world services provided to customers, and that in the con-
sumer perception it is often difficult to separate the software part of a service from
the global service provided.
Therefore, coming to service design methodologies, it is more and more impor-
tant to support the complete service life cycle and to provide methodological
guidelines and tools that start from a global consideration of the requirements for
the services being designed and developed.
While the initial service-based design methodologies have been derived from
consolidated software design methodologies, the need for specific approaches to
service design is being developing over time [ 3, 8] .
Yet, even considering the specific characteristics of services during design, most
of the proposed methods do not provide specific approaches for the requirements
engineering phase.
One emerging approach which proposes linking the requirements engineer-
ing phase to the subsequent design phases has been proposed in [ 6] and further
developed in [ 10] , based on the notion of intentions to specify the goals of the busi-
ness processes in the requirements phases and to design services based on these
requirements.
The goal of this chapter is to discuss the specific characteristics of services and
service life cycle that motivate different methodological approaches and to illustrate
and compare approaches in the first service design phases, focusing on requirements
engineering and service design, and on service compositions.
In the following, in Sect. 2 we illustrate the important aspects in designing ser-
vices and service life cycles, focusing in particular on service compositions. In Sect.
3, we discuss requirements engineering in different service design methodologies,
while in Sect. 4 we compare approaches to designing service compositions. Finally,
in Sect. 5 future work and possible research directions are presented.
2 Designing Adaptive Services
Service design has been studied from different perspectives and in different research
areas. As mentioned in the introduction, the first service design methodologies have
been proposed extending the traditional approaches to software development in the
literature. In the life cycle illustrated in Fig. 1, which emerged from discussion in
the Dagstuhl seminar on Service Oriented Computing [ 9] , some of the characteriz-
ing aspects of service development are included. First of all, a provisioning phase
is explicitly inserted, thus emphasizing that service provisioning is different from
1 S-Cube project web site: http://www.s-cube-network.eu/ .