Reversing the role of the customer: the new ‘customer-as-a-supplier’ supply chain principle for the circular context

This paper evaluates the relevance and sufficiency of a suite of six established supply chain principles for uncertainty reduction in circular supply chains, focusing on plastics in the construction sector. Using a structured intervention-based research approach, two trials with industry consortia designed and implemented closed-loop models for mortar tubs and aggregate packaging, incorporating higher recycled content and new reverse logistics arrangements. Findings confirm that original principles remain relevant but insufficient in circular contexts. We propose an additional principle ‘Customer-as-a-Supplier (CaaS)’ to address uncertainties in quality, timing, and volume of returned materials, and the changing role of customers in closed loop supply chains. CaaS emphasises communication, incentives, convenient return logistics, contamination control, and retailer engagement to enable high-quality material recovery. This extends the existing framework and highlights the active, and changing, role of customers. Future research should test the generality of CaaS and existing principles across diverse closed-loop supply chains.