The current process is 8+60+12+90+10=180 minutes, with 30 active minutes. Reducing only the printing wait from 90 to 45 yields 135 minutes overall. The improvement is 45/180=25%, not 50%. Whether it persists requires further observation.

Critical check: Do not invent observations, remove a quality check without replacement or confuse one queue improvement with total-process improvement.

Final project: Deliver the Fern improvement case: boundary, current map, cause hypotheses, trial plan and a cautious result/standardization decision.