??? The Web services are self-contained (perform predetermined tasks) and loosely
coupled (for independence).
??? The Web services can be dynamically discovered.
??? Composed services can be built from aggregates of preexisting Web services.
A few essential differences between traditional EAI solutions and Web services
(Samtani & Sadhwani, 2001) are presented in Table 1.
Although, the Web services applied to specific EAI scenarios provide an abstraction
and flexibility layer supporting SOA and simplifying the application integration, they
are based on exclusively syntactical-oriented technologies, not defining formally
the semantics of services interfaces and of the data structures of the messages Web
services exchanges. The main reason resulting in the failure of the majority of EAI
implementations (some articles even account for 70% of EAI projects as failure)9 is
that the semantics of different systems have to be formally defined and integrated at
one point. The lack of formal semantics regarding the applications and services to
be integrated makes it difficult for software engineers and developers to manually
interconnect heterogeneous applications, impeding the automation regarding application
integration, data exchange, and complex services composition.
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