Classify the dependency
Document the business purpose, service owner, data involved, system access, subcontractors, critical deadlines, alternatives, and impact if the service becomes unavailable. A low-cost tool can still create high operational or information risk.
NIST guidance treats supply-chain cybersecurity as part of broader enterprise risk management. The depth of review should be proportionate to the dependency and consequences.
Ask for evidence that answers the risk
- Identity, ownership, financial and reputational checks appropriate to the engagement.
- Security, privacy, access, incident, backup, continuity, and subcontractor information.
- Service levels, support path, implementation responsibilities, and acceptance criteria.
- Insurance, licenses, references, or certifications when relevant and independently verified.
- Contract, renewal, pricing-change, termination, data-return, deletion, and transition terms for professional review.
Record the decision and the exceptions
Keep a dated decision record with reviewers, evidence, limitations, approved exceptions, compensating controls, open questions, renewal date, and accountable owner. Reassess material vendors when the service, access, ownership, control environment, or business dependency changes.