As an evaluation system for design management environment, DMES innovates corporate management and reinforces competitive edgy by providing effective design management systems to companies. This study is a case research to diagnose and evaluate design management environment of small and medium-sized companies. Through the process, the design management environment and corporate competitive edge could be improved. The evaluation areas for DMES were 8 in total. However, this case classified 5 areas for design management maturity of a company and put 44 sub-factors for diagnosis and evaluation. As a result, the level of Namdo Mold Corporation’s design application was turned out to be ‘no design management.’ The company had a low level of understanding about design and did not apply its corporate management principle to design and brand identity, losing opportunities to establish a good corporate image. Thus, the researchers of this study evaluated that an effort for clearly establishing a corporate identity is needed so that its management principle can be expressed through its brand image. Based on 5 strategies which were come up according to the analysis result, the researchers established the brand platform and did a color-planning process for the brand so that the corporate management philosophy and identity can be visually expressed. What’s more, the researchers suggested Namdo Mold to use the Basic System for its logo and symbol mark and other Application System. Through DMES, a design management environment that suits a company’s competence could be quantitatively diagnosed and evaluated, proposing new potential for corporate design management. Furthermore, the researchers anticipate that it would contribute to improve companies’ design awareness and corporate competitive edgy.