Vendor stability — how to assess long-term partner viability

5-year supplier relationship is worth 30-40% productivity gain (familiar specs, faster proofing, prepaid stocked items). Stability indicators: (1) 5+ year operating history. (2) Audited annual revenue $5M+ (minimum for stable cash flow). (3) Multi-currency invoicing capability. (4) ISO 9001/14001 certification. (5) Documented succession plan (founder dependency risk). (6) Diversified client base (not >40% from one client). (7) Insurance: $5M+ liability + cargo + product. (8) NDA enforcement track record. Red flags: only WhatsApp/Telegram, factory without verifiable address, prices below market by >30%.