Public defence in Logistics, Martin Zistler, MSc.

The doctoral thesis of Martin Zistler, MSc. "Managing water in supply chains: Essays on risk signaling, responses and water rivalry," will be publicly examined at the Aalto University School of Business on Friday, October 30, 2026.

Water risks can disrupt operations and supply chains, yet firms often overlook water threats. Resilience requires action beyond reporting.
Water shortages, floods and pollution can stop production far from a company’s headquarters—and the disruption can travel through global supply chains. Martin Zistler’s doctoral thesis shows that water should be treated not merely as an environmental indicator, but as a strategic resource affecting business continuity, investment decisions and relationships with suppliers, partners, communities and nature.

The thesis asks how companies compete for water, respond to water risks in their supply chains and signal those risks to stakeholders. The results show that voluntary water disclosures can help distinguish water-resilient companies from vulnerable ones. Concrete water investments and supply-chain actions provide the most credible signals. Also, companies do not compete for scarce water only with other firms. Households and nature are also rivals, although they often have less bargaining power. Regulators and civil-society organizations can reshape this competition through permits, allocation rules, pricing, campaigns, collaboration and lawsuits. Firms overlooking competition for water with these actors may face higher costs, protests, reputational damage, legal disputes or even loss of license to operate. Finally, firms also show a worrying investment pattern: as the expected financial size and time distance of a supply-chain water risk increases, firms invest proportionally less in addressing it. Companies may therefore remain especially exposed to the largest and most distant threats.

The thesis adds new knowledge across an entire supply chain management lifecycle from recognizing water’s importance to water consumption, identifying and assessing water risks, responding and investing, as well as monitoring and reporting. The findings are timely for companies, investors, lenders, suppliers, regulators and civil society. Firms are advised to map water risks beyond their own facilities, including sub-suppliers and distant water basins, to consider the needs of communities and ecosystems and to prioritize concrete supply-chain actions. Investors and business partners can use water disclosures as screening information, while recognizing that disclosures signal exposure and resilience rather than exact forecasts. Policy makers can use the findings to design and enforce allocation, permitting and reporting systems that prevent powerful users from shifting costs and negative impacts to households and nature.

“The thesis shows that water-related disruptions can emerge anywhere in a supply chain, and distant risks are often disregarded. Water resilience requires more than reporting. Firms need proportionate investment, engagement with suppliers and stakeholders, and decisions that account for households and nature. Supply chain water management must be a source of resilience and credibility rather than vulnerability,” states Martin Zistler.

Key words: Supply Chain Management, Water, Risks, Signaling, Factor Market Rivalry, Cumulative Prospect Theory

Opponent: Professor Martin C. Schleper, Neoma Business School and University 
Custos (Chairperson): Professor Katri Kauppi, Aalto University School of Business

Contact information: martin.1.zistler@aalto.fi
Martin Zistler https://www.linkedin.com/in/martinzistler/

Thesis available at: https://aaltodoc.aalto.fi/handle/123456789/50
Thesis available for public display 7 days prior to the defence