Guide · 13 July 2026 · 4 min read
Evidence rots quietly
Case studies age, CVs drift out of date, accreditations expire. Untended, the proof library becomes a liability with a search box.
Bid evidence has a half-life. The flagship case study quietly becomes six years old. The named project director retired. The accreditation on page four lapsed in March. None of this announces itself; it is discovered by an evaluator, at the worst possible moment, on a bid you should have won.
Treat evidence like stock, not archive
A proof library needs the disciplines of inventory: every item owned by someone, dated, reviewed on a cycle, and scored for freshness and completeness. The items that win work are the ones with outcomes and numbers in them, client permission recorded, and a photograph that is not a rendering. Everything else is filler that dilutes the good material.
- Review dates on every item, with expiry alerts, not annual heroics
- Usage tracked: which evidence actually appears in winning bids
- Permission recorded, so reuse is never an awkward question
- Gaps listed by sector, so authorship is planned, not improvised
Write evidence at the moment of victory
The best time to write the case study is the month the job finishes, while the metrics are fresh and the client is pleased. The worst time is the night before a deadline, which is when it usually happens. A standing rule, one page within thirty days of completion, costs little and compounds for a decade.