WSLA Schema for Functionality Based Weight fixing of Non-Functional Parameters of Web Services

Recently Web services have evolved as a cost-effective solution for exchanging information between distributed applications over different operating system, platform, and software environment. The success of such a system is mainly depends on the quality offered by the service and the extent to which the web service meets the customer requirements. So while selection of a service the top priority is given to the functionality related aspects. From the list of service with same functionality the selection of a service is made by evaluating the QoS by considering the domain specific and domain independent attribute that leads to the achievement of maximum functionality. But while monitoring the performance of a service, the quality is mainly evaluated by measuring the non functional parameters such as response time, throughput, availability, reliability and sucessiblity. Satisfied level for these non functional values shows that the web service met the customer needs. In this paper we are proposing a method and a schema to assign functionality related weight to the non functional parameters and thereby evaluate the expected level of QoS at the time of selection itself. Apart from the guaranteed level of non functional values asserted in the WSLA, the weights are also assigned to the non functional parameters to evaluate the actual QoS.