A MIL-HDBK-781A 20% consumer risk reliability demonstration test calls for demonstrating a lower test MTBF of 1000 hours, and is structured to accept on 2 failures, and reject on more than 2 failures
1. test length multiplier (of lower test MTBF)
2. actual MTBF that producer needs to also have a 20% risk
3. Discriminination ratio for producer's risk of 10%
4. Test length