We propose a performance estimation technique for a multi-core segmented bus platform, SegBus. The technique enables us to assess the performance aspects of any specific application on a particular platform configuration, modeled in Unified Modeling Language (UML). We present methods to transform Packet Synchronous Data Flow (PSDF) and Platform Specific Model (PSM) models of the application into Extensible Markup Language (XML) schemes using modeling tool and how the generated XML schemes can be utilized by the emulator program to get the execution results. The technique facilitates us to estimate performance aspects of application mapped on a number of different platform configurations during the early stages of the design process.