Considering that a firm’s service competitiveness comes from customer service representatives (CSRs)’ capability, it is essential to enhance their capability first to create superior customer service. Accordingly, this study provides a way of creating CSRs’ capability by proving how organizational knowledge accumulated in knowledge management systems influences their customer response expertise and speed. Moreover, drawing on studies of organization memory (OM), it is defined by the three dimensions of OM level, OM dispersion, and OM usability. To test the proposed model and hypotheses, this study conducted the structural equation modeling analysis using a total of 373 responses collected on CSRs. The results indicate that both OM level and dispersion greatly increase customer response expertise. Besides, OM level, dispersion, and usability enhance customer response speed. Particularly, OM usability is the most effective in improving customer response speed. Finally, CSRs’ service performance depends on customer response expertise and speed.