How do you calculate a scale-up risk score?

Multiply the severity, occurrence, and detection ratings together. With severity 6, occurrence 4, and detection 3 on a comparable scale, the risk score is the product of the three, shown here as 4.55 after scaling.

What is severity, occurrence, and detection?

Severity rates how damaging the failure is, occurrence rates how often it is likely to happen, and detection rates how likely you are to catch it before it escapes. Higher detection scores mean it is harder to catch.

What is a good risk score?

Lower is better. There is no universal threshold; teams set an action line for their scale. Any single factor that is extreme, especially severity, should trigger action even when the product is modest.

Why multiply instead of add the three scores?

Multiplying makes a risk that is bad on all three axes stand out sharply, and it is the standard FMEA RPN convention so results are comparable across teams and audits.

Can a high-severity risk hide in a low score?

Yes. A high severity paired with low occurrence and detection yields a small product, so many teams require action on any high-severity item regardless of the total. Do not rank on the number alone.

How is this different from the newer Action Priority method?

AIAG-VDA FMEA replaced RPN thresholds with an Action Priority table of high/medium/low. This tool uses the classic multiplicative RPN, which is simpler for quick scale-up triage but should not override severity judgment.

Production Ramp, Scale-Up & Launch Readiness calculator

Scale-Up Risk Score Calculator

The Scale-Up Risk Score turns three judgment ratings, how bad a failure would be, how likely it is, and how hard it is to catch, into a single prioritization number for launch and volume ramp. Launch engineers, quality leads, and PFMEA teams use it to rank the risks of moving a process from pilot to full-rate production and to decide where to spend limited de-risking effort. It matters because scale-up surfaces failure modes that never appeared at low volume: thermal drift, tool wear, supplier variation, and operator load. Scoring each risk consistently on the same scale lets a cross-functional team argue about the right things instead of gut feel.

What this calculator does

Estimate scale-up risk for production ramp, scale-up and launch readiness using production-ready inputs so teams can rank risks and decide which issue needs containment, controls, or escalation first.
Use it when scale-up risk in production ramp, scale-up and launch readiness needs a defensible ranking against other production ramp, scale-up and launch readiness risks for the next review.
It multiplies severity, occurrence, and detection scores into a single risk priority number, the same structure as an FMEA RPN, for a given scale-up failure mode.

Formula used

Scale-up risk score = scale-up risk severity score × scale-up risk occurrence score × scale-up risk detection score
Use the same scoring scale across comparable scale-up risk risks.

Inputs explained

Severity of scale-up failure impact:
Likelihood the scale-up issue occurs:
Ability to detect the issue before escape:

How to use the result

Use it during PFMEA reviews and scale-up planning to rank failure modes and decide which get containment or design action before ramp.
Multiplicative RPN can mask a high-severity risk behind a low product, so always flag any high-severity item for action regardless of its total score, and keep every item on the same rating scale.

Common questions

How do you calculate a scale-up risk score? Multiply the severity, occurrence, and detection ratings together. With severity 6, occurrence 4, and detection 3 on a comparable scale, the risk score is the product of the three, shown here as 4.55 after scaling.
What is severity, occurrence, and detection? Severity rates how damaging the failure is, occurrence rates how often it is likely to happen, and detection rates how likely you are to catch it before it escapes. Higher detection scores mean it is harder to catch.
What is a good risk score? Lower is better. There is no universal threshold; teams set an action line for their scale. Any single factor that is extreme, especially severity, should trigger action even when the product is modest.
Why multiply instead of add the three scores? Multiplying makes a risk that is bad on all three axes stand out sharply, and it is the standard FMEA RPN convention so results are comparable across teams and audits.
Can a high-severity risk hide in a low score? Yes. A high severity paired with low occurrence and detection yields a small product, so many teams require action on any high-severity item regardless of the total. Do not rank on the number alone.

Last reviewed 2026-05-12.