Time-to-success logging for real-robot VLA comparisons
Robot labs comparing VLA policies should log every rollout as a completion time, hard failure, or safety stop, then report the time-to-success distribution with confidence intervals. PhAIL gives a concrete template: Kaplan-Meier CDFs, Human-Relative Throughput against same-fixture human teleoperation, and per-object KS tests for model comparisons.
This workflow addresses a common adoption blocker: two robot policies can show similar fixed-time success rates while one is much slower or has a worse failure tail. In PhAIL’s Franka FR3 benchmark, the best evaluated VLA was about seven times slower than the human reference by RMST ratio, and no inference model exceeded 19% Human-Relative Throughput on any object. A cheap first check is to reuse existing rollout videos and logs, add timestamps for task completion and unrecoverable failures, and see whether the ranking changes when success rate is replaced with the full completion-time distribution.