Abstract: UML-based software models in USDP are functionality-oriented. For the purpose of predicting software performance in the early stage of software development, they should be extended with information required for deriving and specifying variables of perform

Key words: Unified modeling language （UML）, Unified software development process （USDP）, Software performanceprediction, Queuing network model （QNM）, Metamodel, Extensible markup language （XML）, XML-based metadataexchange （XMI）