✓ Free · MIT License Manufacturing Healthcare Quality

FMEA Builder

Every process has failure modes nobody has written down yet. FMEA finds them before a customer does. Severity × Occurrence × Detection scored, RPN calculated, actions prioritized. Any unobserved control gets [NEEDS GEMBA].

⬇ Download Skill How RPN works ↓

Problems This Solves

Three ways FMEA fails before this skill

Quality escapes that were predictable

The failure mode existed in the process. Nobody had ever written it down, scored it, or assigned an action. The customer found it first.

FMEA documents that were never updated

The FMEA was built at launch, filed, and never touched again. Every process change since then added failure modes that aren't in it.

No method for prioritizing corrective actions

The team has a list of failure modes but no system for deciding which ones to fix first. RPN makes the priority explicit, as a rough guide: rank severity first, and never close an item on an RPN cut-off alone.

The Formula

Risk Priority Number = S × O × D

Three independent scores, each 1–10, multiplied together. The product is the RPN, the number used to rank and prioritize corrective actions across all failure modes in the FMEA.

Severity

1 – 10

Occurrence

1 – 10

Detection

1 – 10

RPN

1 – 1000

Severity Scale

What the score means, not just a number

Severity scores the worst-case effect of the failure mode on the customer. It does not consider how likely the failure is, or whether you'd catch it. That's Occurrence and Detection.

9 – 10

Safety or regulatory impact: potential injury to operator or customer, or violation of government regulations

7 – 8

Product or service non-functional: customer cannot use the product for its intended purpose

5 – 6

Degraded function: product works but with reduced performance; customer dissatisfied

3 – 4

Minor defect noticed by most customers: fit, finish, or cosmetic issue; no functional impact

1 – 2

Effect unlikely to be noticed by the customer; detected only by discriminating inspection

Detection is inverted, and most teams score this wrong

A Detection score of 10 means no detection method exists. A score of 1 means the failure is mistake-proof: it cannot reach the next step. High detection scores are bad. If your team's scores cluster around 2–3, ask whether they're scoring it backwards.

Sample Output

What an FMEA Builder report looks like

Example: Injection Molding Process, 3 Failure Modes

Process: Fill → Cool → Eject. Three failure modes scored and prioritized.

Process Step	Failure Mode	Effect	SEV	Cause	OCC	Current Control	DET	RPN	Recommended Action
Fill	Short shot	Part rejected, line stop	7	Low melt temp	4	Visual check at press	6	168	Add in-mold pressure sensor
Cool	Sink marks	Cosmetic defect, customer return	5	Insufficient cool time	5	None	8	200	Set min cool-time interlock; add control
Eject	Part sticking	Scrap, tooling damage risk	6	Draft angle insufficient	3	Operator pull-check	4	72	Review tool design; plan action

RPN interpretation

Sink marks (RPN 200) ranks highest despite lower severity than Short shot, because there is no current detection control (D=8). The skill calls this out explicitly: high Detection scores are the most actionable lever when Occurrence and Severity are fixed.

Action tiers

Three bands. Three responses.

RPN alone doesn't tell a team what to do next. The skill translates the number into a required action tier so every failure mode has an explicit owner and timeline. These are this toolkit's working bands on the older RPN method (AIAG FMEA-4), not an industry standard. The 2019 AIAG and VDA handbook replaced RPN with a separate Action Priority table, so rank severity first, and never close an item because it fell under a cut-off.

Immediate Action

RPN > 100

Assign an owner and a due date before the FMEA session ends. Do not leave this as a to-do list item.

Plan Action

50 – 100

Add to the corrective action log. Review at the next quality review cycle.

Monitor

RPN < 50

Document in the FMEA. Revisit if occurrence data changes or a new control is removed.

RPN > 100 with a Severity of 9 or 10

A safety or regulatory failure mode with any significant occurrence or detection gap requires immediate action regardless of the final RPN. The skill flags these separately. A Severity 9 failure mode is never just "monitor."

Examples

Manufacturing and clinical processes both supported

🏭 Manufacturing

🏥 Healthcare

Injection molding PFMEA: 4 process steps (fill, cool, eject, inspect), 11 failure modes scored. Process was last FMEAed at product launch 3 years prior. Engineering review added 6 new failure modes.

Process: Injection Molding — Gear Housing
Steps: Fill · Cool · Eject · Inspect
Failure modes identified: 11
High-priority (RPN > 100): 3 — all assigned owners before session closed
New modes added vs. original FMEA: 6
[NEEDS GEMBA: confirm current detection controls for Cool and Eject steps]

Medication administration PFMEA for a hospital pharmacy workflow. The skill adapts vocabulary: "customer" becomes "patient," "scrap" becomes "adverse event." Severity 9–10 modes trigger a separate patient-safety callout regardless of RPN.

Healthcare note

Wrong medication and wrong dose failures that can reach a patient usually score at the top of the severity scale, though the scale is your team's to set (healthcare FMEA methods score severity differently). The skill ensures high-severity items are never collapsed into a "monitor" bucket by RPN alone. They surface at the top of the action list with a required immediate response.

What you get

A real run on the sample data

Unedited output. The sample message at the top went to Claude Sonnet 4.6 (an earlier-generation model, so a newer one may word things differently) with this skill pasted in, the same way the steps below show, on September 29, 2026. Scroll inside the frame to read the whole reply.

Open the full image

Installation

Describe the process. Get the FMEA.

Copy the skill. Open fmea-builder.md, select all the text and copy it.

Paste it into Claude. In claude.ai, start a new chat and paste it as your first message, or paste it into a Project's instructions so it's there every time. The free plan works, and free accounts can keep up to five Projects.

Say what's in front of you, in your own words, with any data you have (leave out names). For example, "build an FMEA for [process name]," or paste an existing SOP or process map. Add "just draft it" to skip the questions and get the whole deliverable now. Paste numbers, not a picture of a chart: language models can misread figures. If your plan lets you switch on Code execution in Claude's settings, turn it on so the arithmetic is run, not estimated, and spot-check any number you plan to act on.

See a finished example first (optional): the worked examples are in the download, in the resources/examples folder.

Related Skills

FMEA leads to mistake-proofing and root cause

Once you have a ranked FMEA, the next question is: can we eliminate the highest-RPN failure modes entirely? Mistake-proofing answers that. If a failure has already occurred, root cause finds why.