Target quality of developed vehicle and component is determined in early design stage simultaneously with marketability preset, considering possessed tchnologe capability of company, possessed equipment, development cost and capability of suppliers. This target quality is the final object of mass production, and it must be achieved by performing systematically qualitys evaluation and improving activity on complete vehicle and component in each development stage. Therefore, in development stage with prototype vehicle, target quality can be acquired by confirming quality level and improving problems to achieve target quality. Quality level acquired from development stage shall be maintained and reproduced in PP stage and mass production stage. After market, quality control and guarantee system should be established to promptly and guarantee system should be established to promptly and effectively deal with claims for customers. Now, KAES makes efforts to stabilize quality and perform improvement activity by providing detailed test methods and total management system from vehicles of early development stage.