The specific attributes of agrifood supply chains, along with their importance for the economy and society, have led to an increased interest in the parameters that enhance their effectiveness. Recently, numerous digital tools aimed at improving supply chain effectiveness have been developed. The majority of existing research focuses on optimizing individual processes rather than the overall growth of a food supply chain. This study aims to identify the stages of the information systems planning (ISP) process that affect the success of developing a strategic decision support system (DSS) for improving the decision-making process in the agrifood supply chains. Data were collected from 66 IT executives from Greek small and medium-sized enterprises (SMEs) in the agrifood sector and analyzed using regression analysis. The results revealed that situation analysis is the only stage of ISP that predicts ISP success. These findings can assist managers in appreciating the critical role of ISP for improving the performance of agrifood supply chain operations. Implementing the most appropriate information systems (IS) and digital tools results in increased competitive advantage, cost savings, and increased customer value