A Single Source of Truth (SSOT) is the principle that an organisation should have a clearly defined, authoritative source for a particular type of information so that users and connected systems work from the same controlled data.
In aviation maintenance and engineering, the term is often associated with the Maintenance & Engineering (M&E) system. The M&E system typically acts as the primary operational system of record for aircraft maintenance status, configuration, component history, work orders and other continuing-airworthiness information.
However, a Single Source of Truth does not necessarily mean that every piece of aircraft information must exist in one software platform.
What does Single Source of Truth mean in aviation?
Modern airline engineering environments contain several specialised systems.
An M&E system may control aircraft maintenance history and configuration, while:
an electronic technical log records flight and defect information;
an ERP system manages purchasing and financial information;
OEM platforms contain technical publications;
engine-health systems provide condition-monitoring information;
reliability applications analyse fleet performance;
external MROs and suppliers create additional operational records.
Each system may be authoritative for a different part of the aircraft information landscape.
The important question is therefore:
Which system is the controlled source for each type of information, and how does that information remain consistent when it is used elsewhere?
Single Source of Truth vs One System for Everything
A common interpretation of SSOT is that all operational data should be consolidated into one central system.
In aviation, this is rarely practical.
Specialised systems exist because different operational functions require different capabilities. An engine-health platform, M&E system and ERP system perform different roles and may all contain information that Engineering needs.
A more useful approach is to establish clear systems of record for different information domains and maintain reliable connections between them.
For example, aircraft configuration may be controlled in the M&E system while an OEM remains the authoritative source for its technical publications.
The objective is consistency and traceability across those sources rather than replacing every specialised system with one database.
Why does a Single Source of Truth matter?
When ownership of information is unclear, different teams can begin maintaining separate versions of the same data.
This may lead to:
duplicate data entry;
conflicting aircraft or component records;
locally maintained spreadsheets;
repeated reconciliation between systems;
uncertainty over which record is current;
additional verification before engineering decisions.
These problems become particularly visible when information needs to move between Engineering, CAMO, Maintenance Planning, Technical Records and external partners.
Single Source of Truth and System Integration
System integration helps maintain consistency between authoritative sources without requiring users to recreate the same information manually in several places.
EXSYN's Data Exchange & Integration solution connects M&E, ERP and specialist aviation environments while allowing each system to remain the owner of the information for which it is responsible.
Information can be mapped, transformed and validated before it enters the receiving environment, while exceptions identify where differences need to be investigated.
Single Source of Truth and Aviation Data Continuity
Defining an authoritative source is only part of the challenge.
Aircraft information continues to change and move throughout the aircraft lifecycle. Components are replaced, OEM information is revised, maintenance events update aircraft history and information is exchanged between operators and partners.
The information therefore needs to retain its meaning and relationships as it moves beyond its original system.
EXSYN describes this broader principle as Aviation Data Continuity: keeping aircraft information clean, connected and trusted across systems, organisations and the aircraft lifecycle.
In this environment, the goal is not necessarily one database containing everything. It is a controlled information landscape in which teams know where authoritative information originates and can rely on that information when it is used elsewhere.
