A method of operating a transaction server for use with trace components, providing an execution cost for each trace component, receiving input selecting one or more trace components, running the transaction server with each selected trace component active, monitoring the execution cost of each selected trace component, and providing an updated execution cost for each trace component. The method can also be extended to provide an execution cost for one or more combinations of trace components monitoring the execution cost of any selected trace component combination, and also to provide an updated execution cost for each trace component combination. The method can further comprise maintaining a record of the execution cost of each selected trace component and transmitting the record to a different transaction server, thereby sharing knowledge between connected systems.