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Root Cause Analysis Decision Tree
Which method fits the problem in front of you, how far to dig, and the tests that tell a root cause from a convenient stopping point.
Free to use, change and copy inside your own organization. Editable Word, plus a fillable PDF you can complete on screen.
The problem it solves
Most investigations stop at the first answer that sounds like a cause: operator error, did not follow the procedure, tooling wear. The action that follows fixes a symptom, the nonconformance comes back, and the record says it was closed. This guide walks an investigation from problem statement to a confirmed root cause and escape cause, picks the method that fits the problem, and gives the tests a cause must pass before anyone writes an action against it.
Who uses it, and when
Quality engineers, supervisors and anyone leading or reviewing a cause investigation. At the start of every corrective action, and again at the review where the root cause is accepted.
Part of
CAPA Command Kit.
Clause references: 10.2.1 (with 8.7). Clause numbers only; the standards text is not reproduced, use your own licensed copy.
A management aid, not certification or a registrar audit. Using it does not by itself show conformity to AS9100D or any other standard.
Page 1 of the PDF. Every resource includes a worked example.
Related resources
workbook · Excel · fillable PDFRoot Cause Analysis Worksheet
A structured investigation in one place: problem statement, is / is-not, every candidate cause tested against the data, a 5 Whys chain with evidence, the six root cause tests, the escape cause, and a conclusion that reads Not yet until the work is done.
Free download →
template · Word · fillable PDFFive Whys Investigation Template
A why chain where every answer carries the evidence behind it, a stop test that tells you when you have reached a cause you can change, and a second chain for why the problem got out.
Free download →
workbook · Excel · fillable PDFFishbone (Ishikawa) Analysis Worksheet
Run a cause-and-effect session that ends with tests, not opinions: candidate causes across the six categories, each with how it will be tested, by whom and by when, the result and its status, counted for you and laid out as a printable cause map.
Free download →
workbook · Excel · fillable PDF8D Problem-Solving Workbook
One tab per discipline, D0 to D8, rolled up to a status page: an is / is-not table, containment that is verified, root and escape causes confirmed with data, an effectiveness criterion set before the actions go in, and prevention carried to similar processes.
Free with your email →
worksheet · Excel · fillable PDFCAPA Effectiveness Verification Worksheet
Prove a corrective action worked, not just that it was done: separate containment, correction and corrective action, set a measurable criterion before the action goes in, and hold the record open until the evidence is in.
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These tools help you run the work by hand. When you want the whole picture of your quality system from the records you already keep, that's what the AeroAssure Audit Defense Pack and the IA9100 Transition Gap Analysis do.