Equipment Availability Calculator
Calculate Inherent, Achieved, and Operational equipment availability using MTBF, MTTR, and preventive maintenance downtime.
Core Formula
Availability = MTBF / (MTBF + MTTR) × 100%
Governing Standards
- ISO 14224 — Reliability data
- IEC 60050 — International Electrotechnical Vocabulary
Frequently Asked Questions
What is the difference between inherent and operational availability?
Inherent availability (Ai) considers only corrective maintenance time. Operational availability (Ao) includes preventive maintenance, logistics, and administrative delays.
What is considered good availability?
World-class manufacturing targets >95% availability. Critical infrastructure (power plants, refineries) often targets >98–99%.