Gate outputs

Put a check between what the component produces and what actually happens next. Sample its work, reconcile it against an independent source, or run cases whose correct answer you already know, so errors surface while they are still cheap to reverse.

Put a check between what the component produces and what actually happens next. Sample its work, reconcile it against an independent source, or run cases whose correct answer you already know, so errors surface while they are still cheap to reverse.

Example

Every Sunday you pull the calendar's next-week schedule and check five entries against the swim club and school sites, plus three past weeks whose real schedule you know. Two wrong entries in a row and nothing gets emailed until you look.