Managing Top-down Changes in Service Oriented Enterprises


Xumin Liu
Virginia Tech, Blacksburg, VA


The Internet and the Web technologies provide a convenient platform
for people to manage and share information. As many databases have
become Web accessible, Web services are emerging as new computing
paradigm to deploy and access Web data. Service composition technologies
further utilize Web services to enable seamless integration of online
data. The result will be a Service Oriented Enterprise (SOE), which is
an on-demand and dynamic collaboration between autonomous Web services.
To deploy such an SOE, a key challenge will be how to deal with changes
considering the dynamic Web environment.

In this talk, I will present a framework for managing changes in SOEs.
The key components of the proposed framework include a Web Service Change
Management Language (SCML) and Change Enactment strategies. The SCML is
a formal language to specify a change. SCML is built on a formal model,
which consists of a Web service ontology and an SOE schema. The Web service
ontology defines service semantics, including the functionality, quality
parameters, and context. The SOE schema provides a high level abstraction
of an SOE's properties. Based on the SOE schema, I will introduce a taxonomy
that classifies changes into different categories. I will then present a
set of change operators that deal with each type of changes. Change enactment
is the process of reacting to a change. It consists of three subcomponents:
change implementation, change verification, and change optimization. Change
implementation is to implement the proposed change operators by modifying
an SOE's schema and the participation of its member services. Change
verification is to ensure that the correctness of an SOE is maintained
during the entire process of change reaction. Change optimization is to
select the Web services to ensure that the change can be reacted to in
the best way.