We are interested in this paper in the model-based testing of composed Web services with the aim to study their limitations particularly under various load conditions. In order to realize our solution, we followed an incremental test approach starting with the conformance testing of an instance of aWeb services composition. Then, we studied the load testing in a significant way. With this intention, we carried out the monitoring of these applications during load testing, for after that carrying out an automated analysis of test results aiming, particularly, to identify the causes as well as the natures of possible problems.