Proliferation of web services opens an unleashed opportunity to the service providers compete themselves to satisfy a request. Since numerous functionally similar web services are readily available, identifying pertinent web service to the client's requirement is a challenge. Furthermore, recommending the pertinent web service and not missing the relevant web service are the two complex issues to be addressed in service discovery process. Since the keyword search doesn't bear the underlying semantics and unable to articulate the search query accurately, operation based search has been introduced. The discovery process is matured, if the search must be incorporated with client's QoS requirements. To alleviate the aforementioned difficulties, QoS driven web service discovery approach has been introduced. The gist of the approach is to assist the user to search the pertinent web service based on functional and non functional evaluation. The web services metadata are extracted from the WSDL file and it will be stored in a service pool. The functional and nonfunctional evaluation can be performed by the proposed algorithm, and the aggregated value will be stored in a service pool. The services which are matched with the user query will be provided to the client.