This paper talks about the increase in internet technologies has lead companies to distribute application functions. Since one of the important aspects of these functions is performance, they created a performance engineering tool to build predictive models of the systems being created. They address the issues with PE of developing a representative performance model and getting accurate and quick estimates for performance.
In their case study, they trace types of intranet requests and then import the information into their data model. They conclude that it is possible to compare performance levels of alternate systems without having to create the whole system first.