Most retries repeat the first run because nobody wrote down what actually went wrong. A vague memory ("agents found the summaries unreliable") cannot be tested. A measurable failure can. Before you touch the design, produce a one-sentence failure statement with a number, a unit and a source.
Good: "In the first pilot, 34 percent of 120 drafted responses were edited before sending, and supervisors logged 18 percent as factually wrong."
Bad: "The drafts were not good enough."
The distinction matters because the unit of work you measure must stay constant between the original run and the revised test. Practitioners who write pilot charters describe the evaluation unit as one comparable unit of completed work, and they insist on naming the baseline, its source and its window before launch, since a future target is not a baseline (pilot charter guidance). If the first pilot measured edits per drafted reply, the revised test must measure edits per drafted reply, on the same category of work, with the same review step.
Two habits make this concrete:
- Pull the raw numbers from the first run, not a slide that summarized them. If the first pilot had no baseline at all, write "unknown, discovery required" against that line rather than inventing precision.
- Separate the failure mode from its symptom. A high edit rate is a symptom. The failure mode might be "the model was given no product catalog, so it invented plan names." Your revision should be traceable to that specific mode.
A useful test of whether your failure statement is real: hand it to someone who was not on the first pilot and ask them what number would prove it fixed. If they hesitate, it is still a feeling, not a failure mode.



