Project delivery on time, with agreed quality and assigned budget, is the desire of project-based companies. Time, quality, and cost are determinants of project success; however, organisations suffer from achieving these three success criteria at the same time. Failures in project delivery cause the loss of the competitive advantage. The recent digital technologies introduce smart contracts to supply chain (SC) operations for improving SC processes. Project procurement is the area for smart contract implementation to deliver successful projects and gain sustainable competitive advantages. The aim of this study was in explaining how smart contracts benefit project organisations through project procurement. Qualitative research design guided this research with phenomenology. Semi-structured interviews generated the data. The obtained research data were analysed with thematic, textual, and discourse analysis. Published industry reports were used to triangulate the data. This study demonstrated an integrated relationship model to answer the research question. The research findings initially identified the fact that smart contracts improve procurement efficiency through cost, time, and quality. Secondly, smart contracts build a trust-less platform where reliability is delivered and reinforced with transparency, traceability, and security. This study found that enhanced procurement efficiency and reliability meet requirements to gain sustainable competitive advantages. This study intends to contribute to industry practices and future research. The correlation of project procurement management success, smart contracts, and sustainable competitive advantages are expected to guide feature research and business practices.