Complete firstBounded subject
The scope and purpose of MORT Analysis are stated as a concrete question.
Without scope, MORT investigation record becomes arbitrary.
Method guideOperations
MORT Analysis
A practical method guide: clarify prerequisites and materials, understand the complete process, and look up outputs, pitfalls, and stop criteria.
ComplexityHigh
TimeMehrere Tage bis Wochen
Participants2-6
FormatWorkshop + async
MaturityEstablished
01
Prerequisite
What needs to be finished first
Complete firstAccess to relevant perspectives
secured event chronology, interviews and artefacts, MORT diagram and definitions manual and domain decision makers are available.
Without these perspectives, central claims in MORT investigation record remain unsupported.
02
Preparation
What needs to be ready before start
Materials
secured event chronology, interviews and artefacts, MORT diagram and definitions manual, shared workspace, source links, and decision log.
People / roles
Lead investigator · safety/domain experts · worker representatives · management liaison
Pre-read
Collect secured event chronology, interviews and artefacts, MORT diagram and definitions manual in advance and mark open assumptions.
Time needed
Several days to weeks
Setup
Prepare MORT tree with evidence-based branch assessment and causal linkage visibly and calibrate assessment terms before starting.
03
Core question
The one question this method answers
Which barrier, task, and management factors enabled or failed to prevent the event?
04
Flow
Phases with goal, actions, output and pitfall
MORT is a comprehensive fault tree for events and management systems. Analysts test branches against evidence and mark adequate, less-than-adequate, or not applicable.
MORT investigation record
Fictional worked example
MORT tree with evidence-based branch assessment and causal linkage as a precise working structure with a fictional example.
Top event
Event · loss · boundary
Pump damage, six-hour shutdown.
MORT branch
Path · definition · status
Bypass control: LTA.
Evidence
Source · finding · uncertainty
Register without owner; interview + document.
Correction
System change · owner · effectiveness test
Bypass tag + review; audit after 30 days.
The example demonstrates the domain logic of MORT Analysis; worksheets remain blank.
- 1
Establish event
Establish event
Goal
Produce event basis so the core question “Which barrier, task, and management factors enabled or failed to prevent the event?” can be answered with stronger support.
Inputs for this step
- secured event chronology
- interviews and artefacts
- MORT diagram and definitions manual
Actions
- Secure top event, losses, chronology, and scope.
- Record source, rationale, and open uncertainty directly in event basis.
Output
event basis
event basis · source · uncertainty · next decision
Quality check
Are facts, statements, and interpretation separated?
Pitfall
MORT branches are rated from conjecture or completed without a risk-relevant scope. Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
Timing: 10–20 minutes
- 2
Select branches
Select branches
Goal
Produce analysis tree so the core question “Which barrier, task, and management factors enabled or failed to prevent the event?” can be answered with stronger support.
Inputs for this step
- event basis
- interviews and artefacts
- MORT diagram and definitions manual
Actions
- Select relevant barrier, task, and management branches.
- Record source, rationale, and open uncertainty directly in analysis tree.
Output
analysis tree
analysis tree · source · uncertainty · next decision
Quality check
Is every branch defined through the manual?
Pitfall
MORT branches are rated from conjecture or completed without a risk-relevant scope. Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
Timing: 10–20 minutes
- 3
Evaluate
Evaluate
Goal
Produce rated MORT so the core question “Which barrier, task, and management factors enabled or failed to prevent the event?” can be answered with stronger support.
Inputs for this step
- analysis tree
- interviews and artefacts
- MORT diagram and definitions manual
Actions
- Rate branches as adequate, LTA, N/A, or unknown with evidence.
- Record source, rationale, and open uncertainty directly in rated MORT.
Output
rated MORT
rated MORT · source · uncertainty · next decision
Quality check
Does every rating have a source and rationale?
Pitfall
MORT branches are rated from conjecture or completed without a risk-relevant scope. Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
Timing: 10–20 minutes
- 4
Correct system
Correct system
Goal
Produce corrective plan so the core question “Which barrier, task, and management factors enabled or failed to prevent the event?” can be answered with stronger support.
Inputs for this step
- rated MORT
- interviews and artefacts
- MORT diagram and definitions manual
Actions
- Cluster causal paths and verify systemic corrections.
- Record source, rationale, and open uncertainty directly in corrective plan.
Output
corrective plan
corrective plan · source · uncertainty · next decision
Quality check
Do actions address barrier and management system?
Pitfall
MORT branches are rated from conjecture or completed without a risk-relevant scope. Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
Timing: 10–20 minutes
05
Artifact
What comes out at the end
Sketch: what the artifact looks like
Form
Versioned MORT investigation record with date, sources, owners, and next review.
Versioning / ownership
Retain date, source, assumption state, and decision for every version of MORT investigation record.
Tool alternatives
- MORT investigation record as board or document
- Source and evidence register
- Decision and action log
mort-analysis-working-template.md
Plan MORT Analysis around its domain steps and the concrete decision question.
MORT Analysis: Worksheet
Question
To be confirmed
Desired outcome
To be confirmed
Scope
Full initiative Time: Several days to weeks
Complete this worksheet on paper or in your own document during the work.
Preparation for this scope
Method setup
- Materials: secured event chronology, interviews and artefacts, MORT diagram and definitions manual, shared workspace, source links, and decision log.
- Roles: Lead investigator · safety/domain experts · worker representatives · management liaison
- Advance information: Collect secured event chronology, interviews and artefacts, MORT diagram and definitions manual in advance and mark open assumptions.
- Overall time needed: Several days to weeks
- Setup: Prepare MORT tree with evidence-based branch assessment and causal linkage visibly and calibrate assessment terms before starting.
Prepare for the work steps
Establish event: Establish event
- secured event chronology
- interviews and artefacts
- MORT diagram and definitions manual
Select branches: Select branches
- event basis
- interviews and artefacts
- MORT diagram and definitions manual
Evaluate: Evaluate
- analysis tree
- interviews and artefacts
- MORT diagram and definitions manual
Correct system: Correct system
- rated MORT
- interviews and artefacts
- MORT diagram and definitions manual
MORT investigation record
Top event
Event · loss · boundary
...
MORT branch
Path · definition · status
...
Evidence
Source · finding · uncertainty
...
Correction
System change · owner · effectiveness test
...
Enter only real input, sources, and decisions.
U.S. Department of Energy: MORT User's Manual
Establish event: Establish event
Expected artifact: event basis
event basis · source · uncertainty · next decision
Entry:
...
- Are facts, statements, and interpretation separated?
Select branches: Select branches
Expected artifact: analysis tree
analysis tree · source · uncertainty · next decision
Entry:
...
- Is every branch defined through the manual?
Evaluate: Evaluate
Expected artifact: rated MORT
rated MORT · source · uncertainty · next decision
Entry:
...
- Does every rating have a source and rationale?
Correct system: Correct system
Expected artifact: corrective plan
corrective plan · source · uncertainty · next decision
Entry:
...
- Do actions address barrier and management system?
Open questions and next steps
...
Method guide: https://methodatlas.meierhoff-systems.de/en/methods/mort-analysis/run-sheet
06
Example output
Concrete filled scenario, fictional example
Fictional example for orientation. Counts and timings describe this case and are not universal requirements.
mort-analysis-beispiel.md
Concrete filled scenario, fictional example
Top event: pump damage and six-hour shutdown. Barrier: interlock bypassed during maintenance without a visible tag. Task: restart check lacked a removal step. Management: bypass register had no owner or review. Corrections address tagging, check, and governance; individual blame is not treated as the system cause.
07
Pitfalls
Recognize symptoms and steer against them
Quick overview, the full text is in the matching phase in the flow
- Establish eventMORT branches are rated from conjecture or completed without a risk-relevant scope.View in phase
- Select branchesMORT branches are rated from conjecture or completed without a risk-relevant scope.View in phase
- EvaluateMORT branches are rated from conjecture or completed without a risk-relevant scope.View in phase
- Correct systemMORT branches are rated from conjecture or completed without a risk-relevant scope.View in phase
Trap
Establish event
Symptom
MORT branches are rated from conjecture or completed without a risk-relevant scope.
What to do
Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
Trap
Select branches
Symptom
MORT branches are rated from conjecture or completed without a risk-relevant scope.
What to do
Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
Trap
Evaluate
Symptom
MORT branches are rated from conjecture or completed without a risk-relevant scope.
What to do
Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
Trap
Correct system
Symptom
MORT branches are rated from conjecture or completed without a risk-relevant scope.
What to do
Stabilise chronology and evidence register first, prioritise branches, and use unknown rather than invented ratings.
08
Stop criteria
When to pause, resolve prerequisites, or choose another approach
MORT investigation record answers the core question with traceable evidence or explicitly marked uncertainty.
Owners, next actions, and review dates are named for open points.
Finished the method guide?
Go to the profile for purpose, similar methods, and sources or continue to the next method in the catalog.