Three live tools — 5 Whys, Fishbone Diagram, Pareto Chart — and two more in active development. Built by quality engineers, for quality engineers. No signup. No downloads. Nothing leaves your browser.
Use the tools individually for quick analyses, or chain them together for a complete investigation — from spotting the pattern to preventing recurrence.
Each tool is a standalone browser app — opens instantly, works offline after first load, saves your progress locally.
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.
Build an Ishikawa cause-and-effect diagram across 6M, 6P, or custom categories. Canvas-based, with sub-causes and clean PNG export.
Apply the 80/20 rule to any count data. Auto-sorted bars, cumulative percentage line, 80% threshold marker, and vital-few highlighting.
Score failure modes on Severity × Occurrence × Detection to prioritize risk. Color-coded thresholds and recommended action tiers.
Build a formal 8D problem-solving report across disciplines D0–D8. Used widely in automotive supply chains and supplier complaint resolution.
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 |
|---|---|---|---|---|
| 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 Dev | Pre-launch risk assessment for a design or process; regulated industries | Ranked RPN worksheet | 2–8 hours | CSV |
| 8D Report Dev | Formal customer-facing response to a non-conformance; automotive supply chains | D0–D8 report document | 1–5 days |
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.
30–60 minutes · small team
Best for: single-system outages, individual customer complaints, production line stops.
2–3 hours · 4–8 people
Best for: recurring defects, quality audits, post-mortem reviews that span multiple departments.
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. The site is funded by non-intrusive display ads and optional affiliate links on our recommended-books page. 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 of the finished diagram or worksheet — suitable for presentations, reports, or sharing with your team. 5 Whys analyses can also be printed as text. FMEA and 8D Report (both in development) will add CSV and PDF export.
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. See the three workflow recipes above.
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 and Microsoft Clarity to measure anonymous page traffic only, with full consent-mode controls.
Open the 5 Whys tool and start a real analysis in under ten seconds — no signup, no downloads, no setup.