How do you calculate a warranty exposure score?

Multiply severity by 0.40, occurrence by 0.35, and detection difficulty by 0.25, then sum. With severity 8, occurrence 5, and detection 4, the score is 5.95 on a 10-point scale.

Why is severity weighted highest?

In vertical transport a severe failure can mean a safety event or a stranded car, which carries the largest cost and reputational risk. The 0.40 weight on severity reflects that a serious failure outweighs one that is merely frequent or hard to detect.

What is a good warranty exposure score?

Lower is better. Scores below about 4 are routine, 4 to 7 warrant a documented mitigation, and above 7 should trigger redesign or a hard inspection gate. The example's 5.95 sits in the act-with-a-plan band, driven by high severity.

How is occurrence different from detection?

Occurrence is how likely the failure is to actually happen and generate a callback in the field; detection is how likely you are to catch it before the unit ships. A failure can be unlikely yet nearly invisible at the factory, which still elevates risk.

How does this relate to elevator callbacks?

Callbacks are the field symptom this score predicts. A high occurrence score maps directly to expected callback frequency, and reducing it — through better components or adjustment — is the most direct way to lower warranty cost.

Can I compare scores across different car designs?

Yes, as long as the same team scores them consistently. The weighted score is designed to rank options and designs against each other so you can prioritize where to spend quality effort.

Elevators, Escalators & Vertical Transport Equipment calculator

Warranty Exposure Score Calculator

Warranty exposure on elevators and escalators is dominated by callbacks — the unbillable service trips a unit generates in its first year or two — and those trips can erase the margin a clean bid earned. This calculator adapts FMEA-style risk scoring to rank a unit or feature by warranty risk, weighting how bad a failure is, how often it is likely to call back, and how hard the problem is to catch before the car ships. Reliability engineers, quality managers, and service planners use the score to decide where to add inspection, redesign a fault-prone option, or set a warranty reserve. A high score is a signal to act before the unit leaves the factory, when fixes are cheap.

What this calculator does

Score warranty exposure for elevator, escalator, or moving walkway equipment using severity, occurrence, and detection ratings.
a quality or service manager needs to rank warranty risk before release, shipment, or modernization turnover
It blends severity, expected callback occurrence, and pre-shipment detection difficulty into one weighted warranty exposure score using a 40/35/25 split.

Formula used

Warranty exposure score = severity × 0.40 + occurrence × 0.35 + detection × 0.25

Inputs explained

Warranty severity score:
Expected callback occurrence score:
Pre-shipment detection difficulty score:

How to use the result

Use it during design review or pre-shipment quality gates to rank units, options, or failure modes by warranty risk.
Scores are judgment-based on a 1-10 scale, so they rank relative risk well but are not a dollar forecast of warranty cost.

Current U.S. benchmarks

On-highway diesel averages $4.58 per gallon this week (EIA), trending down over recent periods. Truck tonnage is up 3.4% year over year (ATA via FRED).
U.S. housing starts run at 1,177k per year (Census, May 2026), down 8.7% from a year earlier, the demand driver for building products.
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).

Common questions

How do you calculate a warranty exposure score? Multiply severity by 0.40, occurrence by 0.35, and detection difficulty by 0.25, then sum. With severity 8, occurrence 5, and detection 4, the score is 5.95 on a 10-point scale.
Why is severity weighted highest? In vertical transport a severe failure can mean a safety event or a stranded car, which carries the largest cost and reputational risk. The 0.40 weight on severity reflects that a serious failure outweighs one that is merely frequent or hard to detect.
What is a good warranty exposure score? Lower is better. Scores below about 4 are routine, 4 to 7 warrant a documented mitigation, and above 7 should trigger redesign or a hard inspection gate. The example's 5.95 sits in the act-with-a-plan band, driven by high severity.
How is occurrence different from detection? Occurrence is how likely the failure is to actually happen and generate a callback in the field; detection is how likely you are to catch it before the unit ships. A failure can be unlikely yet nearly invisible at the factory, which still elevates risk.
How does this relate to elevator callbacks? Callbacks are the field symptom this score predicts. A high occurrence score maps directly to expected callback frequency, and reducing it — through better components or adjustment — is the most direct way to lower warranty cost.

Last reviewed 2026-05-12.