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have diffi culties in recognizing the fundamental nature of components, considering the
componentization aspects at the level of code packaging. By treating components as
implementation artifacts during deployment and as larger-grained business objects during
analysis and design, these methods are not well equipped for modeling loosely coupled
coarse-grained components that offer business meaningful services organized in the service-
oriented architecture.
Therefore, the main objective of this chapter is to identify the current methodological
shortcomings of the CBD methods and to present a fi rst cut of a methodology framework
for designing improved and proper CBD and SOA methods. For this reason, the chapter
is organized as follows: fi rst, an account of the current state of the CBD methods and ap-
proaches is given by describing and comparing the most prominent and well documented
CBD-methods. Based on this analysis, a framework for defi ning necessary characteristics
and requirements for an advanced CBD/WS methodology is defi ned, and the chosen method
sample is evaluated accordingly. Finally, suggestions are made regarding the ways of im-
proving the methodology towards comprehensive component-based and service-oriented
systems development support.
THE CURRENT STATE OF CBD METHODS
CBD and WS are evolutionary rather than revolutionary approaches. CBD has evolved
from “divide-and-conquer” modularization ideas and concepts in systems development
(Gartner Group, 1997; Szyperski, 1998). During the last few years, due to the rapid devel-
opment of Internet technology and commercial applications, the CBD paradigm has been
seen as the main strategic imperative for time-to-market quality solutions (Gartner Group,
1997; Butler Group, 1998). Higher productivity, fl exibility, and quality, through reusability,
replaceability, effi cient maintainability, scalability and parallel work are among the claims
and benefi ts made for CBD (Butler Group, 1998; Allen & Frost, 1998).
From a technical perspective Web Services are essentially extended and enhanced
component interface constructs. Using standards for service interoperability, such as XML
and SOAP, Web Services can provide location independent business or technical service that
can be published, located and invoked across the Web regardless of underlying technology
(IBM, 2003). Besides technology, there is a need to architect service-oriented computing
systems. Service-Oriented Architecture (SOA) is an approach to distributed computing that
considers software resources as services available on the network. A basis of SOA is the
concept of a service as a functional representation of a real world business activity mean-
ingful to the end user and encapsulated in a software solution. Using the analogy between
the concept of service and business process, SOA provides that loosely coupled service
components are orchestrated into business processes that support business goals. Similar
initiatives were already proposed in the past, such as CORBA or Microsoft's DCOM. What
is new about SOA is that it relies upon universally accepted standards like XML and SOAP
to provide broad interoperability among different vendors' solutions. And what is more
important, the level of abstraction is further raised, so that the main building blocks of SOA
are now real world business activities encapsulating in the services that offer business value
to the user. Component-based and Web Services technology infrastructures are the ways of
implementing the SOA.
