1. A method for monitoring the performance of an application on a user terminal, the method comprising: instrumenting the application on the user terminal to measure client performance counters on an end user side; assigning the client performance counters to a transaction identification number; storing the client performance counters in a performance database; instrumenting a business application server to measure server performance counters on a server side; mapping the server performance counters to the respective transaction identification number; storing the server performance counters in the performance database; combining the client performance counters and the server performance counters having the respective transaction identification number; and transmitting combined performance counters to a performance monitoring application client.