# Map supply routes and private-sector dependencies before a disaster > Include suppliers, transportation modes, access constraints, and alternative routes in continuity planning before normal supply flow is interrupted. - Canonical URL: https://update.dsesecurity.com/updates/map-supply-routes-and-dependencies/ - Publisher: Detection Systems & Engineering (DSE Security) - Author: DSE Security Editorial Team - Published: 2026-08-25T21:34:30+00:00 - Modified: 2026-08-26T13:27:46+00:00 - Last reviewed by DSE: 2026-08-25 - Resource type: Playbook - DSE priority: Important - Topics: Business Continuity - Reading time: 3 minutes ## What you need to know Include suppliers, transportation modes, access constraints, and alternative routes in continuity planning before normal supply flow is interrupted. ## Potentially affected Organizations that depend on time-sensitive fuel, food, medical, technology, repair, or other physical supplies ## DSE recommendation Map critical supply chains with partners, plan alternate routes and modes, and exercise information-sharing and access decisions. ## Article A purchase order does not show whether a critical supply can reach the site after roads, ports, warehouses, fuel, staffing, or access-control procedures change. Continuity planning needs the physical and organizational path behind the supplier contract. ## Source fact: [FEMA’s Supply Chain Resilience Guide](https://www.fema.gov/sites/default/files/2020-07/supply-chain-resilience-guide.pdf) describes a process for understanding and strengthening supply chains before and during disasters. Its approach includes mapping and analyzing supply chains, engaging stakeholders, taking action, assessing results, and refining the work. The guide emphasizes collaboration with private-sector partners whose operational knowledge is necessary to understand how goods move. The guide calls attention to normal and alternative transportation routes and modes, access and re-entry considerations, and the information needed to support supply-chain decisions. The method is iterative: changing hazards, markets, facilities, and partner capabilities require continued assessment. Mapping can reveal dependencies and options; it cannot guarantee that stock, transport, staff, or infrastructure will be available during a particular incident. ## Boundary FEMA’s guide is planning guidance, not a supplier assurance, traffic authorization, or substitute for emergency-management authorities. Sharing maps, inventories, forecasts, and vulnerabilities can expose commercially or operationally sensitive information, so governance is needed. A named alternate supplier may depend on the same upstream manufacturer, warehouse, carrier, route, power system, or communications service as the primary. ## Applicability questions - Which supplies have a maximum tolerable interruption shorter than their realistic replenishment time? - What upstream facilities, carriers, routes, ports, fuel sources, labor, permits, and communications support delivery? - Which alternatives are contractually available, geographically separate, and technically compatible? - How will delivery vehicles and personnel receive current access and re-entry information? - What information may be shared with public agencies and partners, by whom, and through what protected channel? ## DSE recommendation: Select a manageable set of operationally critical supplies and map them from point of use through local inventory, distributors, carriers, warehouses, and known upstream sources. Record lead time, consumption, substitutions, transport modes, route constraints, minimum staffing, cold-chain or handling needs, and replenishment triggers. Ask partners to validate the map without demanding proprietary detail that is not needed for decisions. Identify shared choke points and develop layered options: increased or redistributed stock, compatible substitutes, alternate suppliers, alternate delivery locations, different modes or routes, and demand reduction. Coordinate access and re-entry assumptions with the relevant authorities before an event. Establish contact roles and a situation-update format. Exercise a disruption that removes the normal route and one major supplier simultaneously, then update contracts and plans from the result. ## Verification and evidence Keep the dated dependency map, partner validations, consumption and lead-time evidence, contracts or letters supporting alternatives, access assumptions, contact tests, exercise injects, decisions, and remediation owners. Confirm at least one alternate by a real order or bounded logistics test where practical. Mark uncertain upstream dependencies explicitly; absence of supplier disclosure is not evidence of diversity. ## Official references - [FEMA Supply Chain Resilience Guide](https://www.fema.gov/sites/default/files/2020-07/supply-chain-resilience-guide.pdf) ## Primary reference - Name: Supply Chain Resilience Guide - Authority: Federal Emergency Management Agency - URL: https://www.fema.gov/sites/default/files/2020-07/supply-chain-resilience-guide.pdf - Source publication date: Not stated by the source ## Citation and use Preferred citation: “Map supply routes and private-sector dependencies before a disaster,” DSE Security, https://update.dsesecurity.com/updates/map-supply-routes-and-dependencies/ Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/ Usage and citation policy: https://update.dsesecurity.com/usage/ Copyright © 2026 Detection Systems & Engineering. All rights reserved.