Enhancing the supplier's non-contractual project relationships with designers

Project delivery involves networks of customers, contractors, sub-contractors, suppliers, and designers. Strong interorganizational relationships are considered relevant to project performance. Previous research has focused on contractual relationships in direct supply chains, with little attention to suppliers and their non-contractual relationships. This study develops and tests a framework of relationship strength and its antecedents in the non-contractual relationship between suppliers and designers as third parties in construction projects. The intent is to identify the key factors relevant to enhancing the supplier's non-contractual relationships with designers. The results reveal the supplier's activeness and technical capability as antecedents to trust, and supplier's technical capability and supplier-designer cooperation beyond project boundaries as antecedents to commitment. The different antecedents of trust and commitment imply alternative pathways for strengthening non-contractual relationships in construction projects, thereby deviating from activities in contractual relationships. Further research is proposed on other types of third parties and other antecedents of commitment.