This is an illustrative sample. It describes the method a GARI briefing uses to trace a supply disruption rather than any event: nothing below refers to a real shock, route or region.
A network briefing starts by naming the node that moved and the hop structure around it. The first hop is the part everyone already sees, usually priced within days. The second hop — the substitution, the re-routing, the change in a downstream input cost — is slower and quieter, and it is the one that lands in a budget. A briefing earns its place by describing the second hop while it is still forming.
The engine treats a disruption as a change in one place and reports what recalculates elsewhere. The output is a set of paths with a band around each, and the width of the band is itself the finding: a narrow band after a shock says the network absorbed it, a widening band says it has not yet. A briefing states which of the two it is seeing, and how strongly.
The closing section is written for the reader's own position: which of the second-hop paths a given cost base sits on, and what would have to be true for that to change. It is dated for the same reason every briefing is dated — so the reading can be checked later against what actually happened.