Managing sustainability in lower-tier suppliers: how to deal with the invisible zone

Purpose: The purpose of this paper is to illustrate how a focal firm can manage sustainability in its lower-tier suppliers which lie beyond the firm’s visible horizon. Design/methodology/approach: This paper presents a new approach to managing sustainability in multi-tier supply chains with an illustrative case study that analyzes how electronic equipment firms make efforts to verify that they are not using conflict minerals. Findings: The nexus supplier (smelters in the electronics supply chain) plays a relevant role in increasing visibility and tracing the source of minerals, thus guaranteeing sustainability upstream in the supply chain. Research limitations/implications: The paper is based on a specific supply chain (i.e. electronics supply chain) and therefore its conclusions might be only partially generalized to other sectors. Practical implications: Firms in complex supply chains need to make efforts to identify and manage nexus suppliers to extend sustainability upstream in the supply chain, especially beyond their visible horizon. Originality/value: The paper focuses on management of sustainability in the invisible zone of the supply chain, which has been neglected in previous literature and is increasingly important to the managerial world in an economy with a growing number of global supply chains.