Free RCA tools
Eight live tools and 63 downloadable templates. Built by a quality engineer, for anyone who has to work out what went wrong — whatever the job title. No signup, no downloads, nothing leaves your browser.
All eight sit on one line: the calculator says whether the problem is worth a formal investigation, the selector says which method fits, and the rest run it. Use them one at a time for quick analyses, or chain them from spotting the pattern to preventing recurrence.
Each tool is a standalone browser app: opens instantly, works offline after the first load, saves your progress locally.
01
Put a dollar figure on the problem: rework, scrap, customer escapes and the firefighting hours nobody books. The output is the business case for fixing the root cause.
02
Write a clear, factual, quantified problem statement for 5 Whys, 8D, A3 or any RCA. Live validation catches blame, solution language, vague words and missing numbers.
03
Not sure which method fits your problem? Four questions — timing, evidence, stakes, audience — and you get the right method, what to pair it with, and whether it needs an 8D or A3 wrapper.
04
Apply the 80/20 rule to any count data. Auto-sorted bars, cumulative percentage line, 80% threshold marker, and vital-few highlighting.
05
Build an Ishikawa cause-and-effect diagram across 6M, 6P, or custom categories. Canvas-based, with sub-causes and clean PNG export.
06
Ask “Why?” five times to drill from surface symptom to verifiable root cause. Step-by-step wizard with input validation and expert tips at every level.
07
Score failure modes on Severity × Occurrence × Detection. Automatic RPN, Pareto-ranked review, CSV and PNG export.
08
Build a customer-ready 8D report across disciplines D0–D8. Used in automotive and aerospace supply chains to answer supplier complaints.
Pick the tool that matches the shape of your problem and the time you have. Most serious investigations chain two of these together.
| Tool | Use when | Output | Time | Export |
|---|---|---|---|---|
| Problem Statement | Before any investigation — write a factual, quantified base that 5 Whys / 8D / A3 / FMEA can hang on | Problem statement in 3 formats | 5–10 min | Copy · TXT · PNG |
| 5 Whys | One incident, one team, you need the root cause before the next shift starts | Linear causal chain | 15–45 min | PNG · text |
| Fishbone | Mixed-perspective team brainstorm; you need to map every possible cause before narrowing | Branching cause map | 45–90 min | PNG |
| Pareto | You have defect / complaint / failure counts by category and need to decide what to fix first | Sorted chart with 80% line | 10–20 min | PNG |
| FMEA | Pre-launch risk assessment for a design or process; regulated industries | Ranked RPN worksheet | 2–8 hours | CSV + PNG |
| A3 | Internal Lean problem-solving and coaching; one-page canvas for PDCA thinking | Single-page structured report | 1–4 weeks | — |
| 8D Report | Formal customer-facing response to a non-conformance; automotive supply chains | D0–D8 report document | 1–5 days | PDF · JSON |
Need help choosing? Read the full RCA tools comparison for side-by-side trade-offs and a decision flowchart.
How practitioners actually chain these together in the field.
Recipe A · 30–60 minutes · small team
Best for: single-system outages, individual customer complaints, production line stops.
Recipe B · 2–3 hours · 4–8 people
Best for: recurring defects, quality audits, post-mortem reviews that span multiple departments.
Recipe C · 1–2 weeks · cross-functional
Best for: Lean / Six Sigma projects, ISO 9001 corrective actions, Kaizen events.
Yes. All tools on 5xWhys.com are free to use with no signup, no subscription, and no paywall. Your analysis data never leaves your browser — we don't store or transmit it.
No account needed. Open any tool and start working immediately. Your in-progress work is saved to your browser's localStorage so you can resume if you close the tab, but nothing is sent to a server.
Yes. Every live tool supports PNG export. FMEA Calculator also supports CSV download for Excel and Google Sheets. 8D Report Generator exports a print-ready PDF in the layout customers expect, plus a JSON file you can save and reload.
Yes. Every tool is responsive and has been tested on iOS Safari, Android Chrome, iPad, and common tablet breakpoints. The Fishbone and Pareto canvas exports adjust resolution automatically for mobile screens.
For a single incident, start with 5 Whys alone. For a recurring quality problem, start with Pareto to identify the vital-few defect categories, then Fishbone to map possible causes for the top category, then 5 Whys to drill into the most likely branch. For a design or process risk assessment, use FMEA. For formal customer-complaint resolution, use the 8D Report framework.
Yes. All analysis happens in your browser. We do not transmit, log, or store your problem descriptions, diagram contents, or analysis results on any server. We use Google Analytics to measure anonymous page traffic only, with full consent-mode controls.