How do you calculate a supplier RPN?

Multiply the severity, occurrence, and detection scores using the same scale for every supplier. With severity 7, occurrence 4, and detection 5, the underlying product is 140, which the tool normalizes to a comparable risk score of 5.45.

What is a good supplier risk score?

Lower is better. There is no universal threshold, but you set an action line for your fleet - say, the top quartile of scores - and target those suppliers for audits or dual sourcing first.

What does a high detection score mean?

In FMEA convention, a high detection score is bad: it means the failure is hard to catch before it reaches the line. A bad bearing lot that passes incoming inspection unnoticed earns a high detection number and drives up the RPN.

Why use the same scale across all suppliers?

RPN is only meaningful for ranking. If one supplier is scored 1-10 and another 1-5, their numbers are not comparable, and you will mis-prioritize where quality effort goes.

Severity vs occurrence - which matters more?

Neither dominates in the formula; they multiply. But a high-severity, low-occurrence item (a rare failure that stops the whole line) often deserves attention even at a modest RPN, which is why you read the three scores, not just the product.

How is RPN different from a simple defect rate?

A defect rate only captures occurrence. RPN also weights how bad the failure is and how likely you are to miss it, so a low-defect supplier of a safety-critical, hard-to-inspect part can still rank as high risk.

Municipal Waste Sorting Equipment calculator

MRF Equipment Supplier Risk Calculator

The Supplier Risk score is an FMEA-style Risk Priority Number (RPN) that ranks the components and suppliers feeding a sorting line by how dangerous their failures are, how often they happen, and how hard they are to catch before they bite. It multiplies a severity rating, an occurrence rating, and a detection rating into a single comparable number. Supplier quality engineers and procurement teams use it to decide which vendors get audits, dual-sourcing, or incoming inspection first. When an undetected bad batch of conveyor bearings or eddy-current rotor magnets can take down a high-throughput line, ranking suppliers by RPN focuses scarce quality effort where it actually reduces downtime.

What this calculator does

Rank the risk of an MRF equipment supplier on severity, occurrence, and detection so the team knows which supplier needs an audit, dual source, or escalation.
Use it when ranking sorter, baler, conveyor, or spare parts suppliers for a procurement review or qualification audit.
It computes a single Risk Priority Number = severity x occurrence x detection, on a consistent scoring scale.

Formula used

Supplier risk score = severity score x occurrence score x detection score
Use the same scoring scale across all suppliers being ranked.

Inputs explained

Failure severity score:
Occurrence likelihood score:
Detection difficulty score:

How to use the result

Use it to triage suppliers and components for audits, dual sourcing, and incoming inspection during supplier qualification and periodic reviews.
RPN multiplies ordinal scores, so very different risk profiles can produce the same number; always look at the individual severity, occurrence, and detection ratings, not just the product.

Current U.S. benchmarks

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 supplier RPN? Multiply the severity, occurrence, and detection scores using the same scale for every supplier. With severity 7, occurrence 4, and detection 5, the underlying product is 140, which the tool normalizes to a comparable risk score of 5.45.
What is a good supplier risk score? Lower is better. There is no universal threshold, but you set an action line for your fleet - say, the top quartile of scores - and target those suppliers for audits or dual sourcing first.
What does a high detection score mean? In FMEA convention, a high detection score is bad: it means the failure is hard to catch before it reaches the line. A bad bearing lot that passes incoming inspection unnoticed earns a high detection number and drives up the RPN.
Why use the same scale across all suppliers? RPN is only meaningful for ranking. If one supplier is scored 1-10 and another 1-5, their numbers are not comparable, and you will mis-prioritize where quality effort goes.
Severity vs occurrence - which matters more? Neither dominates in the formula; they multiply. But a high-severity, low-occurrence item (a rare failure that stops the whole line) often deserves attention even at a modest RPN, which is why you read the three scores, not just the product.

Last reviewed 2026-05-12.