Stress-testing a supply chain network

Each company holds a buffer of inventory, and each link is a flow of goods or transport from a supplier to its customer. A shock eats into buffers. When a company is disrupted, the suppliers that ship to it book a loss on those flows, and a supplier whose buffer runs out passes the loss on to its own suppliers, so disruption climbs the chain toward the raw materials one tier per round. That is the Propagation engine. A second engine, Fulfillment node, instead solves for the orders every company can still fill at the same time; in this sample it gives the same or a milder picture for every preset.

To see a cascade, search for Distribution Center France #2, set Shock this node to −100% and press Apply. Then press play in the results panel to watch the disruption spread upstream over six rounds to 34 companies. The presets under Data & scenario work differently: a macro shock such as a port strike hits many companies at once, so most of its damage is there from the start. Switch between the two engines to compare them, and press Score, then untick Color by scenario, to color every node by its disruption score.