First-pass yield only helps if supervisors trust the count. When operators know the figure will be used to blame a shift, the count quietly softens.
Pick one primary line and define first-pass as parts that leave the final station without rework, repair, or hold. Count units, not lots, when lot sizes vary widely.
Use the inspection sheet already at the station. Add a single checkbox column for “passed without return.” Avoid introducing a new binder that sits empty after week two.
Review the weekly first-pass figure with the supervisors who own the line, not only with the quality office. Ask what constrained the number: tooling wear, incoming material, or staffing gaps on a particular shift.
Once the line team trusts the figure, expand to a second line. Spreading the method plant-wide before trust exists usually produces decorative charts.