Pareto Chart
A Pareto chart is a prioritized bar chart used in supply chain and manufacturing to rank categories by frequency, cost, time, or impact from highest to lowest. A cumulative percentage line overlays the bars, showing how much of the total effect is explained by the 'vital few' causes, helping teams target the dominant contributors to defects, delays, shortages, or service failures.
In a manufacturing plant, Pareto charts are fed by NCR logs, downtime records, receiving discrepancies, pick errors, material shortages, or supplier nonconformance codes, then sorted to reveal which failure modes dominate output loss. For example, if 40% of line stoppages stem from one component shortage, 25% from label mismatches, and 15% from late replenishment, the chart immediately makes the shortage the first corrective-action target instead of treating all causes equally. Warehousing teams apply the same logic to order accuracy, damage, mispicks, and receiving delays, focusing labor and slotting changes on the highest-impact categories. Procurement uses it to identify the small share of suppliers, SKUs, or spend categories driving most cost exposure, supporting targeted sourcing and vendor development. The cumulative percentage line signals when about 80% of the total effect has been reached, marking the dominant causes.
What data types are appropriate for a Pareto chart in inventory control?
Nominal categories with frequency, cost, time, quantity, or impact measures, such as stockout reasons, defect codes, late-receipt causes, or supplier nonconformance counts.
Why is descending order required?
The descending order visually isolates the largest contributors first, which is what makes the 'vital few' analytically obvious.
What does the 80% line mean operationally?
It marks the point where the cumulative categories explain most of the observed impact, so action can be concentrated on the causes left of that threshold.