Table 1.

Relevant characteristics of six supply strategies: direct tender, purchasing from the world market, stockpiling, domestic production, innovation, and loaning; as used in our model

	Direct Tender	Purchasing from the World Market	Stockpiling	Domestic Production	Innovative Supply Strategy	Loaning
Definition	Decision-makers can place orders with suppliers using accelerated processes and without competition [25]	Decision-makers can order products from suppliers from the world market. The English health system is in competition with other health systems [25]	Decisionmakers can implement and operate stockpiles with critical medical supplies. In England, Public Health England created a PPE stockpile designed for an influenza [25]	Decision-makers reached out to companies to start the production of critical medical supplies [25]	Individuals or companies produce critical medical supplies in small batches, such as highlighted in the article by [48]	Decision-makers can loan critical medical supplies from other sectors if they fit in the context. In England limited to ventilators from private medical sector [24]
Production Capacity	Assumption that production capacity equals 5% of production capacity of suppliers reached through world market. Production capacity can be increased with increasing demand [49]	Highest production capacity compared to other supply strategies. Production capacity is based on sources where possible. Production capacity can be increased with increasing demand [49]	Limited to the inventory stored in the stockpile. Initial values were derived from [25]	Assumption that production capacity equals 60% of suppliers reached through direct tender for PPE. Concerning ventilators,”ventilator challenge” in England is used as a base [24]. The initial production capacity is 0 and increases over time	Production capacity is small per project and increases over time as more products are approved. Assumptions based on information about single projects [48, 50] or on information on the”ventilator challenge” [24]	Limited to the availability of critical medical supplies in other sectors. In England, 1200 ventilators were loaned private medical sector [24]
Shipment Time	Shipment time is assumed to be 1.5 months, varies between 1 and 3 months [51]	Usual shipment time around 3 weeks. During height of the COVID-19 pandemic, shipment times of up to 9 months [51]	Shipment within 5 days [52]	Shipment within 5 days Based on information about PPE delivery times by [52]	Shipment within 5 days	Shipment within 5 days
Vulnerability	Share of unusable critical medical supplies purchased [25]	Export restrictions Delayed shipment times [25]	unknown	unknown	unknown	unknown
Input of Decision-Makers	Setup time Order buffer	Setup time Order Buffer	Equipment of stockpile Operations of stockpile	Setup time Order Buffer	Setup time Government support Order buffer	Setup time