The quality offer by web service is becoming the high priority for user and varies studies to search and select web service according to their Quality of Service as well as functionalities have been proposed.
Quality of service depends upon numbers of attributes. Every attribute of the QoS has its own effect on overall quality of service, which will change every time based on the service and user requirement. However, most of the researches in this field are concentrated on the study of each independent attribute of web service or based on their pre-defined priority of attribute. The paper propose an approach for calculating the priority of attribute based on user preference by comparing each attribute to each succeeding attribute. The paper use geometric mean and sum of product concept to calculate the weight of parameters for generating the rank of service. Through the proposed algorithm user can easily calculate the weights and select the web service provider based on their QoS preference. The paper includes results of case studies performed on a system built using the proposed approach. Results show that the weights of QoS attributes and rank of service provider are changed based on user’s preferences.