How do you calculate mix ratio error risk?

Multiply the severity, occurrence, and detection scores, each rated 1-10. With severity 9, occurrence 4, and detection 7, the raw product is 252, which this tool scales to a 6.75 risk score for easier comparison.

What is a high mix ratio error risk score?

Because severity for off-ratio cure is almost always high (8-10), any moderate occurrence combined with weak detection pushes you into action territory. Treat the 6.75 in the example as a clear flag for added ratio verification.

Why is detection weighted so heavily for adhesives?

Off-ratio adhesive often passes a visual and even a light touch test while being structurally deficient. If you cannot reliably detect a bad mix, the detection score is high and the overall risk climbs sharply regardless of how rarely it happens.

Severity vs. occurrence: which should I attack first?

You usually cannot lower severity, the consequence of a weak structural bond is fixed by the application. So you drive risk down by reducing occurrence with poka-yoke dispensing and improving detection with ratio checks or cure verification.

How do I lower the score after rating it?

Add a verified meter-mix ratio check, color-change or stoichiometry indicators, and lot-tracked cartridges. Each control either cuts occurrence or strengthens detection, both of which pull the multiplied score down.

Is this the same as a standard FMEA RPN?

It uses the same severity-times-occurrence-times-detection logic as an FMEA risk priority number, scoped specifically to adhesive mix-ratio failure so your bonding team can compare mix steps consistently.

Adhesives, Sealants & Industrial Bonding calculator

Mix Ratio Error Risk Calculator

Mix Ratio Error Risk is an FMEA-style risk priority number focused on the single most common failure mode in two-part adhesives: dispensing the resin and hardener off their specified ratio. An off-ratio mix can look and feel cured while having a fraction of its design strength, which makes it dangerous and hard to catch. Process engineers, bonding line leads, and supplier-quality teams use this score to decide which mix steps need poka-yoke, ratio checks, or supplier intervention before a part ships. It turns a gut feeling about a dispenser into a number you can rank and act on.

What this calculator does

Score risk from two-part adhesive mix-ratio errors using severity, occurrence, and detection weakness.
a process engineer needs to assess risk before approving a two-part adhesive mixing method
It multiplies severity, occurrence, and detection scores into a single risk priority number for adhesive mix-ratio errors.

Formula used

Mix ratio error risk score = severity score × occurrence score × detection score
Higher scores identify bonding issues that need engineering review, process controls, or supplier action before release.

Inputs explained

Off-ratio cure severity:
Mix error occurrence likelihood:
Detection weakness:

How to use the result

Use it during PFMEA, after a mix-related field failure, or when qualifying a new meter-mix dispenser or cartridge system.
The score is ordinal, not linear: a 6.75 is not literally three times worse than a 2.25, so use it to rank and trigger review, not as an absolute probability.

Current U.S. benchmarks

The producer price index for industrial chemicals stands at 344.336 (BLS, May 2026), up 16.1% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 11,391 plastics and rubber products establishments employing about 815,988 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate mix ratio error risk? Multiply the severity, occurrence, and detection scores, each rated 1-10. With severity 9, occurrence 4, and detection 7, the raw product is 252, which this tool scales to a 6.75 risk score for easier comparison.
What is a high mix ratio error risk score? Because severity for off-ratio cure is almost always high (8-10), any moderate occurrence combined with weak detection pushes you into action territory. Treat the 6.75 in the example as a clear flag for added ratio verification.
Why is detection weighted so heavily for adhesives? Off-ratio adhesive often passes a visual and even a light touch test while being structurally deficient. If you cannot reliably detect a bad mix, the detection score is high and the overall risk climbs sharply regardless of how rarely it happens.
Severity vs. occurrence: which should I attack first? You usually cannot lower severity, the consequence of a weak structural bond is fixed by the application. So you drive risk down by reducing occurrence with poka-yoke dispensing and improving detection with ratio checks or cure verification.
How do I lower the score after rating it? Add a verified meter-mix ratio check, color-change or stoichiometry indicators, and lot-tracked cartridges. Each control either cuts occurrence or strengthens detection, both of which pull the multiplied score down.

Last reviewed 2026-05-12.