Leveraging Normative Control for Embedding Sustainability in Supply Chains: A Strategic Approach to Green Purchasing and Supplier Engagement.

Abstract

Audits, certifications and codes of conduct remain central to sustainable procurement, yet their capacity to produce lasting change in supplier practices appears limited. This thesis asks how normative control which is governance through shared values, trust and socialisation might extend supplier engagement beyond compliance.

Semi-structured interviews with procurement, sourcing and sustainability professionals, across seven organisations and six sectors, were analysed through a grounded theory-inspired coding process yielding three aggregate dimensions.

Formal governance emerges as a necessary but insufficient foundation. Relational and developmental practices (trust, dialogue, diagnosis before sanction, supplier capability development) build on it and may support engagement beyond the minimum. How far they do so depends on context: supplier importance, buyer leverage, resources, business logic and external pressure. Notably, normative and commercial motivations coexisted in participants' accounts rather than competing.

The thesis proposes an empirically grounded framework in which normative engagement complements formal governance, its reach conditioned by the buyer–supplier relationship. It contributes to understanding how normative control travels across organisational boundaries, and offers practical guidance for procurement.