root-cause-paretolisted

# Root-Cause Pareto A Pareto chart is easy; a Pareto that survives challenge in a management meeting is not. The difference is four disciplines applied before the chart exists. ## Workflow 1. **Pick the unit of measure deliberately.** Occurrences, minutes, or money - choose the one closest to the pain being managed and say why. Ranking breakdowns by *count* when one category costs 10x more *minutes* per event points the team at the wrong problem. When in doubt, show count and impact side by side. 2. **Enforce category hygiene before counting:** - Categories must sit at one granularity level (no "Mechanical failure" next to "Sensor S-114 misaligned") - "Other/Miscellaneous" must stay under ~15% of the total; if it is bigger, the categorization failed - split it before proceeding - Merge synonyms and near-duplicates (free-text logs always contain them; list the merges made) 3. **Normalize by exposure before comparing.** Line A with 3 shifts will "lead" any raw ranking against Line B with 1 shift. Divide by machine-hours, orders, or units produced when comparing across lines, shifts, or periods - state the exposure base used. 4. **Check stability.** A Pareto from one bad week is an anecdote. Compare the ranking across at least two comparable periods; only categories that stay on top deserve investment. Note rank changes. 5. **Rank, plot, and go one level deeper on the #1 category.** Break the top category into its own sub-Pareto or apply 5-why prompts to its most fre