Who is this research for? Supply chain executives, procurement leaders, and sustainability professionals responsible for managing global supplier networks and ethical sourcing practices.
Top Answer
Research suggests that supplier codes of conduct often fail to improve supply chain outcomes because they rely on compliance and enforcement rather than collaboration. While widely adopted, their impact depends less on the rules themselves and more on how companies engage suppliers, build relationships, and support continuous improvement across multiple tiers.
Executive Summary
Research by Dr. Sebastian Brockhaus and Dr. Florentina Bardan (Monte Ahuja College of Business, Cleveland State University) and Dr. Remko van Hoek (Department of Supply Chain Management, Sam M. Walton College of Business, University of Arkansas) examines why supplier codes of conduct (SCOCs) have not delivered meaningful improvements in global supply chain sustainability.
Using a multi-method approach, the study combines a 25-year longitudinal analysis of SCOCs (1999–2024) with 20 in-depth interviews with supply chain leaders. The findings suggest that while SCOCs have become nearly universal and expanded in scope, they remain largely legalistic, zero-tolerance documents focused on banning specific practices.
In practice, most companies enforce these codes primarily at the tier-1 supplier level, with limited visibility or influence further upstream. This creates a disconnect between widespread adoption and persistent issues like labor violations and environmental risks.
The research introduces a maturity framework showing that most organizations operate in a compliance-driven model (orchestration), where buyers impose rules. Higher-performing approaches move toward collaboration (choreography), where companies and suppliers jointly define goals, share responsibility, and pursue continuous improvement. Ultimately, the study indicates that improving supply chain outcomes requires shifting from enforcing rules to enabling coordinated action across the network.
Expert Insights: What should leaders know about supplier codes of conduct?
Why do supplier codes of conduct struggle to drive real change beyond tier-1 suppliers?
Dr. Remko van Hoek notes: “While a buyer can request a supplier to uphold the SCOC standards with their suppliers, the reality is that the buyer does not have a direct trading or contractual relationship with tier-2 and 3 suppliers. Because of that, the SCOC loses one of its benefits; it is a simple add to a contract and terms of working together. Many buyers have very partial view of who their tier 2 suppliers are also.”
→ Takeaway: Supplier codes often lose influence beyond tier-1 because buyers lack direct visibility and contractual leverage over deeper-tier suppliers.
What practical steps can companies take to make supplier codes actually influence behavior?
Dr. Remko van Hoek adds: “Make it part of the conversation. Don’t just ask for a signature upon supplier set up, make it part of how you work together with suppliers, ask them for plans to improve sustainability and raise the bar over time for suppliers. And be willing to walk in case of non-compliance!”
→ Takeaway: Integrate supplier codes into ongoing collaboration, set clear improvement expectations, and enforce consequences for noncompliance.
How does a collaborative approach change day-to-day supplier management?
Dr. Remko van Hoek explains: “Because the road to a more socially and environmentally sustainable supply chain is a journey, our ambitions to make progress for the good of the regions in which we do business and for the good of our competitiveness take time and effort. If we collaborate with our suppliers, we can go further faster and better together!
→ Takeaway: Collaboration enables companies and suppliers to make faster, more meaningful sustainability progress by working toward shared long-term goals.
Link to the Original Research
Published in Journal of Business Logistics (2026)
Frequently Asked Questions
Why are supplier codes of conduct so common?
They are a standard mechanism for setting expectations around labor, environmental, and ethical practices across global supply chains, with adoption rates exceeding 80%.
If companies use them widely, why don’t they work better?
Because most are implemented as compliance tools rather than engagement tools, limiting their influence beyond direct suppliers.
What is the biggest limitation of current approaches?
A lack of visibility and accountability beyond tier-1 suppliers, where many risks actually originate.
What does a better approach look like?
A more collaborative model where companies and suppliers share responsibility, invest in improvement, and align on long-term sustainability goals.
