Web Services and the Use in eCommerce

HMV Group is a famous international books, music and video retailer. It combines two powerful retail brands; HMV for music, video and games and Waterstone's for books. Both are leaders in their respective fields.

The Group operates from 579 shops, located in eight territories around the world, offering widespread appeal. HMV has 384 stores in six countries, and Waterstone has the other 195 shops (HMV 2006). After merging Waterstone, HMV did not get much profit from it. The development of HMV was not successful as expected.Although HMV has move to online market successfully, it faces the fierce competition from supermarkets and other rivals (e.

g. Sony). The UK business of HMV made trading very difficult in autumn, despite the improvement during Christmas period. Now, music is the biggest product category, and then DVD. They are influenced by the emergence of online market. Both physical and digital products are distributed.

Currently, HMV has a strong position to improve their eCommerce to compete against the supermarket chains (HMV notes 2006). Therefore, a comprehensive strategic planning of eCommerce development is necessary.And the technologies in eCommerce are especially important to the computer services manager. In this report, Web services technologies and their use in eCommerce are introduced and explained in detail.

There are many different definitions of Web Services. Benatallah (2002) defines Web services are loosely coupled Internet-accessible software entities delivering functionalities provided by business applications and process. Carey et al. (2001) indicates it is platforms providing the required functionalities to integrate business applications across companies.Web services are also considered as a distributed information system (Gustavo, A.

et al. 2004). The explanation from W3C (Booth et al. 2004) is more detailed, "A web service is a software system designed to support interoperable machine-to-machine interaction over a network.

It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standers. "From the definition of Web services, we can see clearly, the services here are not the services from a business perspective. They are not regarded as customer services on the Web sites. Web services here can be applied to eCommerce, for example, Internet banking, search engines, auctioning sites, supply chain management, etc (Benatallah 2002).

But they are different from the common services. Many Web services are base on three components: the service requester, service provider, service registry (Gustavo, A. et al. 2004).

The service requester is a role has a need to be fulfilled by the services.The service provider is a role that provides services for the specific need. The service registry - also called service broker - is a role that provides a searchable repository of service descriptions where service providers publish the services and service requesters find services and obtain binding information for these services (Tsalgatidou and Pilioura, 2002). Figure 1. 1 is the service-oriented architecture of Web services.

It shows these three roles and operations. The operations are publish, find, and bind. The three actors perform the operations on service and service description.Figure 1. 1 Web Services actors, objects and operations (Source: Gottschalk, K. et al.

(2002)) Web service and the description are created by a service provider, and published with a service registry based on UDDI. Once a Web service is published, the service can be found by a service requester through the UDDI interface. Then the UDDI registry provides the service requester with a WSDL service description and a URL (uniform resource locator) pointing to the service itself. This information can let the service requester directly bind to the service and invoke it (Gottschalk, K.

et al. , 2002).The operations of Web services are described by standardised XML messaging. UDDL, WSDL here are standards related to Web services, which are explained in the following section. Besides the service-oriented architecture, Web services architecture can be described from another point view - Web services architecture stack.

As Figure 1. 2 shows, it involves many layered and interrelated technologies. There are many ways to visualize these technologies, just as there are many ways to build and use Web services (Booth et al. , 2004). We can see from the figure, communications locate the networking layer.It is an XML-based messaging layer that facilitates communications between Web services and their clients.

The layer above is messaging layer, which is based on SOAP. SOAP is an XML protocol that facilitates the publish, find, bind, and invoke operations described previously. WSDL is a specification that describes available Web services to clients. These descriptions take the form of XML documents for the programming interface and location of Web services. On the top of the stack are the processes like discovery and aggregation.

The discovery processes concern WSDL and UDDI as the operation described previously.This is the service flow layer of the stack. It facilitates the composition of Web services into workflows and the representation of this aggregation of Web services as a higher-level Web service (Gottschalk, K. et al.

, 2002). The rest of layers in the stack are optional and will be used as business needs. The company needs to consider the security and management aspects. These items must be addressed at each layer of the stack. The solutions at each layer may be independent of one another.

More of these vertical towers will emerge as the Web services paradigm is adopted throughout the industry (Gottschalk, K. et al. , 2002).