Reliability Engineering

Pareto Analysis

Pareto analysis ranks problems by their contribution to total loss so teams can focus on the few causes creating the greatest impact.

What this term means in maintenance

Pareto analysis ranks problems by their contribution to total loss so teams can focus on the few causes creating the greatest impact.

How Pareto analysis works

Failures or losses are grouped by a consistent category and ranked from largest to smallest.

Possible measures include:

  • Failure count
  • Downtime
  • Maintenance cost
  • Production loss
  • Repeat work
  • Safety events
  • Spare-parts usage

Practical example

A plant records 200 hours of breakdown downtime. A Pareto chart shows that three failure categories account for 125 hours. Improvement work can focus on those categories first.

Choosing the correct measure

The ranking changes depending on whether the team uses event count, downtime, cost, or consequence. A frequent low-impact problem may rank highly by count but low by downtime.

Data quality

Useful Pareto analysis requires consistent failure codes and meaningful categorization. Large “Other” or “Unknown” categories reduce its value.

Common mistake

The 80/20 rule is a useful idea, not a guaranteed mathematical result. Teams should act on the actual distribution in their data.

Keep exploring connected CMMS, reliability, and maintenance planning terms.

Glossary FAQs

What is the purpose of Pareto analysis?

It ranks problems by contribution to total loss so improvement can focus on the largest sources.

Should Pareto analysis use failure count or downtime?

Use the measure matching the business question. Count, downtime, cost, and consequence can produce different rankings.

Does Pareto always follow the 80/20 rule?

No. The rule is a useful principle, not a guaranteed distribution.

Turn Maintenance Definitions Into Action

MaintBoard helps plant and facility teams move from scattered maintenance records to organized work orders, preventive maintenance schedules, spare parts control, inspections, calibration, and audit-ready history.