In today's highly competitive environment, a goal-oriented supply chain needs coordination to manage the interdependent activities of supply chain partners. The role of coordination mechanisms is critical in achieving supply chain performance. We thus suggest that supplier coordination and customer coordination influence performance, operationalised in this paper under two dimensions, e.g., quality and flexibility. Moreover, drawing on contingency theory, we suggest that the relationships are contingent upon factors such as firm size and clockspeed. Using empirical data collected from 197 production/operations managers of Chinese manufacturing firms, a regression analysis approach is employed to test the theoretical framework. The results provide support for the four direct and positive relationships between each coordination mechanism studied and quality and flexibility performance. The interaction between supplier coordination and size was directly and positively related to quality performance (large size effect). However, the interaction between customer coordination and size was directly and negatively related to flexibility performance (small size effect). The interaction between supplier coordination and clockspeed was directly and positively related to only flexibility performance. Implications for managers and academics and suggestions for future research are offered.