Formerly, coffee practitioners only needed to learn the requisite coffee brewing skills. Today, they must also be able to identify the quality of coffee beans, select the appropriate roasting method, and explain to customers the country of origin and production process for each variety of coffee they sell. Therefore, professional competency and competency development has become ever more critical for the coffee service industry. Therefore, this study used expert interviews and literature reviews to explore the professional competency and working attitude of practitioners in the coffee service industry and explored the significant aspects/criteria of competency development. The study adopted the IAA (importance-attention analysis) technique to evaluate the status of competency development aspects/criteria, and determined the NRM (network relation map) based on the DEMATEL (decision-making trial and evaluation laboratory) technique. The results reveal that IC (implicit capability) and the EA (explicit attitude) are the primary influencers for the coffee industry's competency development. The study also proposed the adoption paths of competency development using the NRM (network relation map) approach. This study makes several recommendations for enhancing the professional competency and working attitude for coffee practitioners and provides some strategies for improving competency development and sustainable talent cultivation.