The growing demand for quality and performance has become a discriminating factor in the field of software applications. Specifically in the area of web applications, performance has become a key factor for success creating the need for new types of performance evaluation models and methods capable of representing the dynamic characteristics of web environments.In this paper we will recall seminal work in this area and present AWPS, a tool for automatic web performance simulation and prediction. AWPS is capable of (a) automatically creating a web performance simulation and (b) conducting trend analysis of the system under test. The operation and usage of this tool is demonstrated in a case study of a two-tier architecture system.