A method to evaluate QoS of web services required by a workflow

The Web services technology for invoking external applications from a workflow engine provides significant benefits to the WFMS. With the increasing number of web services that provide similar functionality, it is important to find the best web service that meets the user´s needs, including both their functional and non functional requirements. The non-functional description of the service requires specifying at run time, the quality attributes that can influence the choice of a web service offered by a supplier. In this sense, it is essential to use metrics to evaluate the quality characteristics of Web services (QoS) in order to filter out Web services discovered, and obtain the most suitable one. The dynamic behavior of Web services regarding the development of new services and constantly changing existing ones, requires a continuous evaluation process, leading to capture web service information with respect to their quality and performance evaluation as requested by the workflow. This paper proposes a quantitative measurement method that allows evaluating QoS of web services, and provides a value that allows the comparison and selection that best meets the required characteristics.