thay thế, đánh giá / justiï cation ¬ được phép. Những người tham gia trong thí nghiệm thứ hai tham gia hai"Các tác giả mang lại một phương pháp tiếp cận cảm giác thông thường để các chủ đề phức tạp của các công ty định giá. | INTRODUCTION TO SERVICE-ORIENTED ARCHITECTURES 283 Figure The SOA find-bind-execute model. Services are software components with a well-defined interface that is implementation-independent. A key aspect of an SOA is the separation of the service interface from its implementation Mahmoud 2005 . The benefits from adopting an SOA approach include Services are self-contained. Services are loosely coupled. Services can be dynamically discovered. Composite services can be built from aggregates of other services. SOA uses the find-bind-execute model as shown in Figure . Service providers first register their service in a registry. This registry is then used by consumers to find services that match certain criteria. If the registry has such a service it provides the consumer with a contract and information on accessing the service. The greater agility afforded by an SOA will also allow organisations to respond to the needs of the market more quickly and in ways that are more attractive to the customer. The SOA is particularly applicable to the Telecommunications market where customer and operational support costs are high and customer satisfaction is a key differentiator. However there is evidence to suggest that companies with complex internal organisations and supply chains will find that large scale SOAs are not achievable without semantic descriptions of service components that can aid service discovery and integration. For example Brodie 2003 Chief Scientist at Verizon Communications stated that There is a growing consensus that Web Services alone will not be sufficient to develop valuable and sophisticated Web processes due the degree of heterogeneity autonomy and distribution of the Web. Before the huge promise of Web Services become industry strength a lot of work is needed and semantics holds a key . 284 A SEMANTIC SERVICE-ORIENTED ARCHITECTURE It is apparent that Web Services alone are not enough to implement an SOA and enable the advantages that this .
