The DK4 was a significant step forward for Chinese metro wagon construction, and provided a suitable carriage for the Pyongyang Metro, and the Beijing Subway (through the DK3). Some of the flaws with the DK4, observed after ten years of running with the Pyongyang Metro were that the car body was still somewhat heavy, and should be further lightened, the bogie had a shorter than desired lifespan, better electrical systems; doors, compressors and controllers were more complicated than necessary for maintenance, and the quality of workmanship in assembly should be improved.
