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

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