In recent decades, lean and globalized supply chains have shown considerable improvements in inventory levels, lead times, and service levels, but a global disruption like COVID-19 pandemic has exposed the hidden vulnerabilities of these supply chains. The pandemic has shown that supply chains need to be assessed on the scale of survivability or viability. Viability in supply chains is the ability to adapt dynamically and make structural changes to survive during disruption and secure the needs of the market and society. Resilience and survivability are two aspects of viability addressed through studies 1 and 2 respectively.
A global pandemic is unique because disruption timelines vary for different geographical regions. Study 1 expands on previous literature by comparing synchronous and asynchronous reopening of facilities at different echelons in a global supply chain with the help of a multi-period discrete event simulation model with varying demand and production capacities. The simulation experiments show that for low demand upon reopening, asynchronous reopening gave better supply chain performance than the synchronous reopening of facilities at different echelons.
In study 2, we use a dynamic ecosystem model to demonstrate the emergence of viability in the supply chain. By viewing a 3-echelon supply chain consisting of suppliers, manufacturers and retailers as a dynamical system, we attempt to define the viability kernel in terms of the strategy sets available to each echelon. Through numerical experiments, we examine the impact of demand disruption on the dynamic system and provide an insight into how stakeholders in the supply chain can expand their strategy set to ensure the viability of their supply chain.