Based on transaction cost economics and social exchange theory, the purpose of this study is to investigate the significant relationship developing factors in supply chain that may help to reduce the transaction costs and to examine the impact on relational commitment. The integrated framework is tested by applying structural equation modeling for 170 Finnish SMEs. The results present the impact of economic and social factors on transaction cost and relational commitment. The findings indicate the important interaction effects between economic and social factors in relation to minimize transaction cost along with important implications for managers to develop long-term business relationships.