Build a Second-Source Contingency File: Dependencies, Gaps, and Switch Conditions

A second-source contingency is not a backup supplier you have already found. It is a record you own: what you currently depend on one supplier for, where a second source is not yet qualified to take that work, and the conditions under which you would actually move it. Preparing it now means a disruption becomes a decision you execute rather than a search you begin.

This article gives you the file structure and a blank worksheet to copy. It is editorial guidance for buyers, not legal, customs, or regulatory advice.

A named alternative is not the same as a usable one

Most buyers can name another factory. Far fewer can say which parts of the job that factory is cleared to take. A second source only helps when the scope is already written down; otherwise the early days of a disruption go to discovery — drawings, tooling, finishes, packaging, approvals, and shipping arrangements that lived only with the original supplier.

Treat the second source as a set of capabilities to be proven, not a company to be found.

Part one: map what you actually depend on

Work through these groups and record only what you can point to in your own records. Leave the rest marked unknown.

• Product definition — drawings, revision level, tolerances, materials, finishes, colour or appearance standards, and any customer-specific requirements you have documented.
• Tooling and fixtures — moulds, dies, jigs, and test fixtures; who owns them, where they sit, and what duplicating or moving them would involve.
• Inputs and sub-suppliers — components, resins, coatings, and packaging, including anything your supplier buys from a sole source of its own.
• Approvals and test records — what was approved, whether it was a sample or a production run, what the approval covers, and who holds the reports.
• Packing, labelling and shipping — packing specification, carton marks, labelling, and the documents your receiving side expects.
• Commercial terms — price basis, payment terms, currency, minimum quantities, lead-time commitments, and any capacity understood to be held for you.

Shipping terms deserve their own line: an Incoterms rule describes delivery responsibilities, and it does not by itself establish quality requirements or payment terms. Record quality and payment separately.

Part two: record the qualification gaps

For each dependency, write today's state next to what a second source would have to prove before taking it over. Mark each gap as verified by you, claimed by the supplier, or unknown. Unknown is a legitimate answer and a useful one, because it shows where the real work sits.

Dependency	Current supplier today	Second source: verified / claimed / unknown	What would prove it

Gaps tend to appear in predictable places: tooling that would need duplicating, materials that need a true equivalent rather than a substitute, sample approval that has never been repeated at production scale, test reports you do not hold yourself, packaging that was never specified in writing, and capacity that exists but is not reserved for you.

Part three: write the switch conditions before you need them

A contingency nobody can trigger is decoration. Distinguish review triggers from move triggers.

• Review triggers — signals that mean open the file and re-check it: a missed commitment, a quality escape at incoming inspection, a slow or unclear response, a change to the price basis, a country or partner risk flag, or a change in your own volumes.
• Move triggers — conditions under which named work actually transfers, and how much of it transfers.

Condition / signal	Who decides	What moves	Must be true first	How hard to reverse

Keep the must-be-true-first column honest. If a precondition is that a second source has passed a production-scale run, write that down. That precondition is your real contingency timeline, and it is better recorded than assumed.

What public due diligence research can and cannot tell you

Country research and company or partner risk research are a reasonable part of filling the file. The Perform Due Diligence guidance from the U.S. International Trade Administration covers country and company or partner risk research and links to official screening resources and commercial guides.

Read the output carefully. A screening or research result is a check, not a certification: it does not certify a supplier's capability, quality system, financial condition, or conduct, and it belongs alongside your own verification rather than in place of it. Any certificate a supplier offers should be recorded with its issuing body and scope, and checked against the work you actually intend to give it.

Questions about legal, customs, or regulatory obligations are outside the scope of this article; confirm them with your own qualified adviser.

Keep the file owned and current

These are suggestions, not requirements. Give the file a named owner rather than leaving it with whoever is free. Re-check it when the product, the supplier, or the shipping arrangement changes. Store it where purchasing and quality people can both reach it. Treat any entry marked claimed or unknown as open work rather than a closed item.

Where Sourcing Desk fits

Keep the dependency and gap sections with your draft buyer brief and identify which missing evidence would change your switch decision. The on-site Sourcing Desk worksheet does not submit a request or qualify a second source. Any supplier claim, quotation, qualification outcome or timeline needs separate confirmation.

Next step

Open a blank document, copy the tables above, and fill in only what you can source from your own records today. Mark everything else unknown rather than guessing. The unknowns are the real scope of your second-source work, and that list is the most useful thing you can send for review.