Operations Analysis method

MORT Analysis

Analyzes accidents systematically through the Management Oversight and Risk Tree, barriers, and management factors.

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.

Core question

Which barrier, task, and management factors enabled or failed to prevent the event?

Plan MORT Analysis Method guide

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Participants: 2-6
Time: Mehrere Tage bis Wochen

MORT Analysis uses MORT tree with evidence-based branch assessment and causal linkage. Assessments remain justified and context-bound.

Paper illustration of MORT Analysis with its method-specific working model.

Establish event
Establish event
Secure top event, losses, chronology, and scope.
Select branches
Select branches
Select relevant barrier, task, and management branches.
Evaluate
Evaluate
Rate branches as adequate, LTA, N/A, or unknown with evidence.
Correct system
Correct system
Cluster causal paths and verify systemic corrections.

Update after new evidence or a material context change and retain the previous version.

A good fit when

For serious events with sufficient investigation authority and a trained analysis team.

Ideal for

Severe incidents
Safety and facility investigations
Audits with a claim to completeness
Systemic weakness analysis

Not good for

Quick wins
Small everyday disruptions
Teams without MORT experience or coaching

Outputs

MORT investigation record
MORT investigation record with traceable sources, assumptions, and domain decisions.
Decision and review trail
Owners, dates, and next review for MORT investigation record.

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

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.

U.S. Department of Energy: MORT User's Manual

First step

Start with the core question: Which barrier, task, and management factors enabled or failed to prevent the event?

Open the method guide

Good to do first

Operations

Causal Factor Analysis

Supplies the reconstructed event chain that is checked here along the control branches.

Where to go next?

Operations

Barrier Analysis

Examines the protective barriers identified as gaps in detail for effectiveness.

Operations

Fault Tree Analysis

Models an identified critical gap as a fault tree for deeper analysis.

Deep dive

Purpose

For a safety-relevant event or a system with high protection requirements, the method examines where controls failed. It exposes both technical and organizational gaps.

How it works

The event is mirrored against a reference model of barriers, controls, and management assumptions. This shows whether the failure arose from individual gaps or from overlooked systemic weaknesses. The analysis is especially strong when several layers of protection could fail at the same time.

In detail

MORT Analysis systematically checks controls, barriers, and management assumptions against each other for complex damage events. Careful fact-gathering and disciplined work on the reference tree are central. The method pays off when systemic oversight gaps become visible that simple root-cause analyses would miss.

Facilitation

Secure evidence, control assumptions, and the protection model early, so the view of the event is not glossed over afterward. The benefit grows when missing barriers are cleanly distinguished from poorly managed conditions. Close with strengthened layers of protection, responsibilities, and a clear statement of which gap gets closed first.

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

Open method guide

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Sources and topics

Topics

Root cause Safety Systemic Incident

Sources

Noordwijk Risk Initiative Foundation: NRI MORT User's Manual (2nd edition)nri.eu.comActively maintained MORT User's Manual by the Noordwijk Risk Initiative Foundation; workflow and limitations are original teaching material.

Artifact templates

MORT Analysis: WorksheetPlan MORT Analysis around its domain steps and the concrete decision question.

markdown

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.