Operations Mapping tool

Root Cause Tree Analysis

Maps evidenced conditions that explain the problem and shows which can be changed.

A cause tree decomposes an observed problem into possible contributing conditions and checks each branch against evidence. This is a general cause-tree analysis, not a proprietary diagnostic system or a decision-selection tree.

Core question

Which evidenced conditions explain the problem and which can we usefully change?

Plan Method guide

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Participants: 2-8 participants
Time: 60–120 minutes initial tree; evidence checks separately

Paper illustration for Root Cause Tree Analysis

Problem
Problem
Record expected state, actual state, period and extent.
Causal branches
Causal branches
Branch possible direct conditions and ask how they arose.
Branch review
Check branches
Check each causal claim using logs, documents, observations or a targeted test.
Actions
Countermeasures
Act on confirmed influenceable conditions and distinguish prevention from immediate correction.

New evidence changes branch status; judge countermeasures only after implementation and suitable observation time.

A good fit when

For recurring or bounded failures with accessible event data.

Ideal for

Incidents
Quality Problems
Complex Troubleshooting

Not good for

Small known defects
Groups without data access

Outputs

Reviewed cause tree
Cause tree with supported, rejected and open branches plus actions on confirmed influenceable conditions.
Action with impact review
The action plan names owners, a date, and the later effectiveness check. Open branches of the cause tree remain visible for further investigation.

Root Cause Tree Analysis· worksheet

Fictional example

Top event

Which concrete deviation is being explained?

Fictional: 12 course registrations received no confirmation within ten minutes on Tuesday.

Tree and links

Record direct conditions, subcauses and joint prerequisites with IDs.

E0 missing confirmation ← H1 sending fails OR H2 message is discarded. H1 ← H1a token expired AND H1b sending uses that token. H1a ← H1a1 expiry reached AND H1a2 no timely renewal.

Evidence status

Which source supports or rejects each branch?

Fictional logs confirm expiry and use of the old token. Stored queue entries reject H2. The operating plan lacks a renewal process, supporting H1a2.

Actions and review

What corrects the event and what prevents recurrence?

Renew token and resend twelve confirmations in a controlled way. Jan adds expiry alerting and renewal ownership; simulate the next expiry in a test.

All example details are fictional and illustrate the application.

US Department of Energy: Root Cause Analysis Guidance

First step

Specify problem, period and deviation from expectation; preserve timeline, logs and affected people as sources.

Open the method guide

Good to do first

DevOps

Blameless Postmortem

Supplies the incident's event data that gets linked in the cause tree.

Where to go next?

Operations

Standard Work Analysis

Anchors the confirmed countermeasure as the new binding work standard.

Operations

Kaizen Event

Implements the confirmed countermeasure in a focused improvement workshop.

Deep dive

Purpose

For a problem with several suspected causes, the method builds a causal structure instead of a mere list. It makes visible how causes connect and where the strongest points of leverage lie.

How it works

Branches are built out from the visible effect until the deeper conditions become recognizable. Every link stays testable, so hypothesis and evidence don't drift apart. The tree structure sharpens the view on paths with high impact and high plausibility.

In detail

Root Cause Tree Analysis structures causes as a branching landscape of hypotheses instead of forcing a linear explanation. Every branch needs a connection to evidence, uncertainty, and testability. A tree becomes cause work once the strongest paths lead to targeted tests and countermeasures. Weak branches stay marked instead of being smoothed over.

Facilitation

Put the visible symptom at the top and only allow branches whose causal link is justified or testable. The tree gives the most when unknown connections stay openly marked instead of being prematurely smoothed over. End the session with tests for the strongest branches and a plan for missing evidence.

The method guide walks execution through 4 phases, timing, 4 pitfalls, and clear stop criteria.

Open method guide

Your perspective

Does this method help with your work?

Your feedback helps shape the next improvements to methodatlas.

Sources and topics

Topics

Root cause Tree Incident Quality

Sources

US Department of Energy: Root Cause Analysis Guidanceenergy.govArchived primary RCA guidance on causal factors, evidence and corrective actions; not current compliance guidance. Editorial tree representation.

Artifact templates

Root Cause Tree Analysis: WorksheetSpecify problem, period and deviation from expectation; preserve timeline, logs and affected people as sources.

markdown

root-cause-tree-analysis-working-template.md

Specify problem, period and deviation from expectation; preserve timeline, logs and affected people as sources.

Root Cause Tree Analysis: Worksheet

Question

To be confirmed

Desired outcome

To be confirmed

Scope

Complete cycle Time: 60–120 minutes initial tree; evidence checks separately

Complete this worksheet on paper or in your own document during the work.

Preparation for this scope

Method setup

Materials: Timeline, logs, tree workspace, evidence register and action list.
Roles: Process experts, affected operators, data experts and independent facilitator.
Advance information: Specify problem, period and deviation from expectation; preserve timeline, logs and affected people as sources.
Overall time needed: 60–120 minutes initial tree; evidence checks separately
Setup: Place the event at the top; branch causal hypotheses below with IDs and evidence status beside each branch.