This thesis addresses the question of what would be a domain independent taxonomy that is capable of representing the non-functional properties of conventional, electronic and web services. We cover all forms of services, as we prefer not to make any distinction between the three forms. Conventional service descriptions, such as newspaper advertisements, are rich in detail, and it is this richness that we wish to make available to electronic and web service descriptions. In a conventional service context, when we ask a service provider for details, perhaps by phoning the service provider, we are seeking ways to assist with decision making. It is this same decision making or reasoning that we wish to be available to electronic services. Historically, services have always been distinguished according to some criteria of a service requestor. Examples are price, payment alternatives, availability and security. We are motivated to ensure that the criteria used to evaluate conventional services are also available for electronic and web services. We believe that the ability to richly and accurately describe services has significant applicability in the areas of electronic service discovery, dynamic service composition, service comparison, service optimisation, and service management. In particular, the increased level of descriptive depth will also facilitate more thorough decision-making by a service requestor. Whilst we acknowledge the importance of service functionality, this thesis is primarily concerned with the non-functional properties of services. A service is not a function alone. It is a function performed on your behalf at a cost. And the cost is not just some monetary price; it is a whole collection of limitations. This thesis is all about these. We believe that to accurately represent any service, a description requires information relating to both the functionality and the associated constraints. We consider these constraints over the functionality of the service to be non-functional properties. We believe that a service description is only complete once the non-functional aspects are also expressed. We undertook a significant analysis of services from numerous domains. From our analysis we compiled the non-functional properties into a series of 80 conceptual models that we have categorised according to availability (both temporal and locative), payment, price, discounts, obligations, rights, penalties, trust, security, and quality. Our motivation is to provide a theoretical basis for automated service discovery, comparison, selection, and substitution. The need to describe a service is analogous with labelling for goods or products. Product labelling occurs for the safety and benefit of purchasers. Why is the same labelling not afforded for the benefit of service requestors?

Web Services are self-contained, self-describing, modular applications that can be published, located, and invoked through XML artefacts across the Web. Web services technologies can be applied to many kinds of applications, where they offer considerable advantages compared to the old world of product-specific APIs, platform-specific coding, and other &ldquo / brittle&rdquo / technology restrictions. Currently there are millions of web services available on the web due to the increase in e-commerce business volume. Web services can be discovered using public registries and invoked through respective interfaces. However how to automatically find, compose, invoke and monitor the web services is still an issue. The automatic discovery, composition, invocation and monitoring of web services require that semantics will be attached to service definitions. The focus of this thesis is on the composition of web services. The approach taken is to extend the DAML-S ontology that is used to define the semantics of services to include the &ldquo / succeeding services&rdquo / for any service provided. These definitions for individual service instances are declared by the service providers. They are presented to the users of the service to construct a workflow in a mobile environment. The workflow generated is represented both graphically in the mobile device and in XML-format as a BPEL4WS document. The aim of this thesis is to prove that it is possible to build a semi-automatic web service composition utility incorporating semantic constructs, using a mobile device. The generated workflow is suitable for deployment on an engine where it can be executed multiple times with different configurations.