How do you calculate a documentation risk priority number?

Multiply the severity, occurrence and detection scores together. With severity 6, occurrence 4 and detection 3, this model returns a documentation burden risk score of about 4.55 on its normalized scale, used to rank the gap against others.

What is a good documentation burden score?

Lower is better. There is no universal threshold, but items clustering at the high end of your scale should be worked first. The value matters mainly relative to your other scored gaps, not as an absolute pass/fail.

What do severity, occurrence and detection mean here?

Severity is how damaging the documentation gap is if it reaches the customer, occurrence is how often it happens, and detection reflects how easily you catch it before release — a high detection score means it is hard to catch, which raises risk.

Why multiply the three scores instead of adding them?

Multiplication makes any single high dimension dominate, so a catastrophic-severity gap that is also hard to detect scores far higher than three mediocre factors. That amplification is what makes RPN useful for triage.

How is this different from a general FMEA?

The math is identical FMEA logic, but it is scoped to documentation and records rather than hardware failure modes — the failure is a missing, wrong or unfindable document, which in a regulated fab still stops work.

Can I compare scores across different tool programs?

Only if both programs use the same severity, occurrence and detection scale definitions. Without a shared rubric the numbers are not comparable, which is why standardizing the scale is the first step.

Semiconductor Fab Equipment Manufacturing calculator

Documentation Burden Calculator

The Documentation Burden score applies FMEA-style risk priority numbering to the paperwork that ships with semiconductor fab equipment — installation manuals, process qualification records, ECN traceability and safety documentation. Quality engineers, technical publications leads and compliance owners use it to rank which documentation gaps most threaten a tool install or an audit. In a fab environment, a missing calibration record or an outdated interlock diagram is not a cosmetic issue; it can halt a qualification or fail a customer's SEMI S2 review. This calculator multiplies severity, occurrence and detection into a single comparable risk score so limited technical-writing resources go where the exposure is highest.

What this calculator does

Estimate documentation burden for semiconductor fab equipment manufacturing using production-ready inputs so teams can rank risks and decide which issue needs containment, controls, or escalation first.
Use it when documentation burden in semiconductor fab equipment manufacturing needs a defensible ranking against other semiconductor fab equipment manufacturing risks for the next review.
It multiplies severity, occurrence and detection scores into a documentation risk priority number for ranking gaps.

Formula used

Documentation burden risk score = documentation burden severity score × documentation burden occurrence score × documentation burden detection score
Use the same scoring scale across comparable documentation burden risks.

Inputs explained

Severity of a documentation gap:
Likelihood the gap occurs:
Ability to detect the gap before release:

How to use the result

Use it during documentation reviews, pre-shipment audits, or when triaging a backlog of manual and record defects across a tool program.
The score is only as good as the scoring scale; inconsistent rater judgment across reviewers makes cross-item comparisons unreliable.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
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 11,261 computer and electronic products establishments employing about 815,443 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate a documentation risk priority number? Multiply the severity, occurrence and detection scores together. With severity 6, occurrence 4 and detection 3, this model returns a documentation burden risk score of about 4.55 on its normalized scale, used to rank the gap against others.
What is a good documentation burden score? Lower is better. There is no universal threshold, but items clustering at the high end of your scale should be worked first. The value matters mainly relative to your other scored gaps, not as an absolute pass/fail.
What do severity, occurrence and detection mean here? Severity is how damaging the documentation gap is if it reaches the customer, occurrence is how often it happens, and detection reflects how easily you catch it before release — a high detection score means it is hard to catch, which raises risk.
Why multiply the three scores instead of adding them? Multiplication makes any single high dimension dominate, so a catastrophic-severity gap that is also hard to detect scores far higher than three mediocre factors. That amplification is what makes RPN useful for triage.
How is this different from a general FMEA? The math is identical FMEA logic, but it is scoped to documentation and records rather than hardware failure modes — the failure is a missing, wrong or unfindable document, which in a regulated fab still stops work.

Last reviewed 2026-05-12.