A clear specification helps developers to understand the system??™s nonfunctional
aspects and guides them toward choosing a proper system design
pattern early on in development.
???. Precision and flexibility: To allow value-added services for dynamic service
discovery as well as automatic and customizable composition and integration,
the QoS specification should have precision and flexibility. Precision means
that it should answer the questions of when, which, where, what, and how the
specification should be evaluated against the Web service (Sahai, Durante, &
Machiraju, 2002). Flexibility permits the specification of customized metrics
for diverse Web services.
???. Object-oriented.style:.Because of the widespread acceptance of object-oriented
design principles, it would help if the definitions for QoS requirements
were also object oriented. When developers know the overall interface??™s QoS
requirements, it makes sense for lower-level interfaces to inherit QoS requirements
and reuse the QoS constraints from the overall interface.
Web Serv ces D scovery and QoS-Aware Extens on
Copyright ?© 2007, Idea Group Inc.
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