A method is provided for building calling context trees of an application to identify a thread or a device affecting a throughput of a transaction relating to the application. The method obtains profiles of call stacks of multiple threads. The method obtains wake-up profiles which are the call stacks of a notifier thread and a waiter thread, from among the multiple threads, in a case that the waiter thread leaves from a sleep state. The method builds the calling context trees to indicate transitions of methods tracing callee relations and wake-up relations based on the profiles of the call stacks and the wake-up profiles, wherein each method is represented by a node having an average thread number. The method extracts and displays tree portions which are transitively reachable from a calling context tree for the transaction and which include the thread or device affecting throughput.