The boundary-spanning role of first-tier suppliers in sustainability-oriented supplier development initiatives

PurposeThis study aims to study how first-tier suppliers (FTs) operate as boundary-spanners between the focal firm and second-tier suppliers (STs) in extending sustainability-oriented supplier development (SSD) initiatives up the supply chain.Design/methodology/approachAn exploratory multi-case study approach in the apparel industry is adopted, comprised of four cases focused on occupational health and safety issues. The paper uses primary semi-structured interviews and observation data and secondary documents, and it is informed by the boundary-spanning and social capital theory.FindingsThe influence of downstream social capital on the upstream boundary-spanning actions of FTs is highlighted. More specifically, it is found that the cognitive and relational capital that exists in the downstream relationship between an FT and the focal firm affects whether the FT adopts compliance- or improvement-oriented boundary-spanning actions in their upstream relationships with STs. Particularly important aspects of cognitive and relational capital are highlighted while the phenomenon of FTs adding their own personal interpretation to sustainability requirements when fulfilling their boundary-spanning role is identified.Research limitations/implicationsA distinction is made between compliance- and improvement-oriented boundary-spanning actions. A deeper insight into the boundary-spanning role of FTs in extending SSD initiatives up the supply chain to STs is provided along with a deeper understanding of how this role is impacted by social capital.Practical implicationsFocal firms should seek to build adequate cognitive and relational capital with their FTs before deploying SSD initiatives to extend their reach further upstream in the supply chain. In doing so, it is also important to be cognisant of the social capital that exists between FTs and STs.Originality/valueThe paper contributes to the SSD literature by going beyond the buyer–FT dyad to examine the FT's boundary-spanning role in the wider buyer–FT–ST chain relationship. The study theoretically and empirically draws out the importance of relation-specific assets through the social capital lens.