The document discusses using system simulation and emulation to evaluate the feasibility of adding a low-floor extension (LFE) to existing light rail vehicles (LRVs) to improve accessibility. A simulation found the LFE increased trip time and energy use. An emulation on a test train found traction motors were fine but friction brakes overheated, showing limitations. Simulation was accurate and flexible, while emulation provided real-world operating experience but was difficult to modify. Both tools were useful for decision making on the LFE concept.