How is the bearing life risk score calculated?

Multiply severity by 0.40, occurrence by 0.35, and detection by 0.25, then add them. Scores of 6, 4, and 3 give 2.4 + 1.4 + 0.75 = 4.55.

Why weight severity higher than detection?

A catastrophic bearing seizure that trips a critical compressor matters more than one you can catch early on a spare pump. The 0.40 weight makes consequence the dominant driver.

What is a high bearing risk score?

On this 1-10 scale, scores above about 6 warrant immediate condition monitoring or replacement planning. The default 4.55 is moderate — watch it, but it is not an emergency.

Is this the same as an FMEA RPN?

It is a weighted variant. Classic RPN multiplies all three (giving 72 here), which over-punishes middling ratings. This weighted average keeps scores on the same 1-10 scale and easier to compare.

How do I score detection for a bearing?

Low detection scores mean you catch wear early via vibration or temperature trending; high scores mean failure arrives with little warning. The default 3 reflects decent monitoring coverage.

Does this replace L10 bearing life calculation?

No. L10 predicts fatigue life from load and speed; this ranks risk for prioritization. Use L10 to size bearings and this score to decide where monitoring effort goes.

Pump, Compressor & Rotating Equipment Assembly calculator

Bearing Life Estimate Calculator

The Bearing Life Estimate is a weighted risk score that ranks how much attention a bearing on a pump, compressor, or motor deserves before it fails. Reliability engineers and rotating-equipment planners use it to triage which machines need vibration monitoring or a proactive replacement. Rather than a raw multiplicative RPN, it blends severity, occurrence, and detection with fixed weights so consequence dominates but early-warning capability still counts. It turns three quick judgments into a single comparable number you can sort a fleet by.

What this calculator does

The Bearing Life Estimate is a weighted risk score that ranks how much attention a bearing on a pump, compressor, or motor deserves before it fails.
Use it when bearing life estimate in pump, compressor and rotating equipment assembly needs a defensible ranking against other pump, compressor and rotating equipment assembly risks for the next review.
It computes a weighted bearing risk score: severity times 0.40 plus occurrence times 0.35 plus detection times 0.25.

Formula used

Bearing Life Estimate risk score = severity × 0.40 + occurrence × 0.35 + detection × 0.25

Inputs explained

Failure severity if bearing fails:
Likelihood of early bearing wear:
Ability to detect bearing degradation:

How to use the result

Use it during FMEA reviews or maintenance-strategy setting to prioritize which bearings get condition monitoring first.
Scores are judgment-based inputs, not measured L10 life — calibrate ratings against real failure history to stay honest.

Current U.S. benchmarks

Industrial electricity averages 8.66 cents per kWh across the U.S. (EIA, Apr 2026), up 5.5% from a year earlier. Energy-intensive steps carry this directly into unit cost.
Manufacturing hourly earnings average $30.27 (BLS, Jun 2026), up 4.4% from a year earlier. Median machinist pay is $28.24/hr (OEWS 2025), with state medians on each state page. Manufacturers have 529k open positions nationally (BLS JOLTS).
Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).
The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).

Common questions

How is the bearing life risk score calculated? Multiply severity by 0.40, occurrence by 0.35, and detection by 0.25, then add them. Scores of 6, 4, and 3 give 2.4 + 1.4 + 0.75 = 4.55.
Why weight severity higher than detection? A catastrophic bearing seizure that trips a critical compressor matters more than one you can catch early on a spare pump. The 0.40 weight makes consequence the dominant driver.
What is a high bearing risk score? On this 1-10 scale, scores above about 6 warrant immediate condition monitoring or replacement planning. The default 4.55 is moderate — watch it, but it is not an emergency.
Is this the same as an FMEA RPN? It is a weighted variant. Classic RPN multiplies all three (giving 72 here), which over-punishes middling ratings. This weighted average keeps scores on the same 1-10 scale and easier to compare.
How do I score detection for a bearing? Low detection scores mean you catch wear early via vibration or temperature trending; high scores mean failure arrives with little warning. The default 3 reflects decent monitoring coverage.

Last reviewed 2026-05-12.