Enterprise Architecture for Banks: BIAN, DORA and Where to Start
A bank starts with its capabilities, its applications and their owners. BIAN serves as a reference for comparison; the DORA chain then connects critical or important functions to ICT third-party providers and contracts.
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Where a bank starts
A bank establishing its enterprise architecture starts from what it is able to do: its capabilities. Lending, payments, account management and customer onboarding are described with their processes, the applications supporting them and the people accountable for them. An unknown owner is recorded as unknown until someone is assigned.
Systems accumulated over several decades, and the integrations between them, make every change expensive. A capability supported by several applications signals duplication worth examining. The first scope can stay narrow, such as an online lending request, then widen as owners confirm their objects.
BIAN as a reference for comparison
The Banking Industry Architecture Network, BIAN, is an independent, member-owned, not-for-profit organisation founded on 29 April 2008. Its members include banks, software vendors and consultancies. Its Service Landscape categorises and organises Service Domains, each describing a bounded business function.
The Service Landscape is released in versions. Version 14.0, published in February 2026, rationalises definitions and renames, removes or adds Service Domains, particularly for payments. BIAN also publishes semantic APIs describing the exchanges between these domains.
A Service Domain belongs to the industry reference; it does not replace one of the bank’s capabilities. Business owners compare scopes and record matches, differences and the version consulted. A reference API does not prove that an existing interface is compatible: its data, rules and errors need detailed review.
TOGAF describes a method for developing enterprise architecture. BIAN provides a banking-specific reference to compare with the bank’s own architecture. The two work together: in ArchiLU, the architecture document follows the TOGAF approach, and the bank records its BIAN mappings in the same repository.
The DORA chain
Regulation (EU) 2022/2554, DORA, has applied since 17 January 2025 to credit institutions and the other financial entities within its scope. Each entity maintains a register of information on its contractual arrangements with ICT third-party service providers. In Luxembourg, the CSSF and the Commissariat aux Assurances are the competent authorities, each for the entities it supervises.
To maintain the register, the bank connects each critical or important function to its processes, the applications serving them, the ICT services, their providers and their contracts. In ArchiLU, each function carries its DORA criticality, and exposure analysis traces a provider up to the functions that depend on it. A missing link stays visible. The chain documents the dependencies the register needs; it does not establish compliance.
Getting started in ArchiLU
An instance’s foundation can start from your own repository, a reference catalogue or a dataset. An industry model such as BIAN for banking loads through the import workbook; a licensed reference is flagged as such.
The capability map shows, for each capability, the applications supporting it, directly or through a process. Redundancy stands out when several applications support the same capability. Each owner declares the exercise state of their capability. For practice, a fictitious mid-sized bank installs in an instance, with its repository, its board and its audit.
In ArchiLU
Frequently asked questions
- What is BIAN?
- The Banking Industry Architecture Network is a member-owned, not-for-profit organisation founded in 2008. It publishes the Service Landscape, which organises banking Service Domains, as well as semantic APIs.
- Does BIAN replace TOGAF?
- No. TOGAF describes a method for developing architecture; BIAN provides a banking-specific reference. A bank can follow the TOGAF approach and compare its objects with the Service Domains.
- Where should a bank start its enterprise architecture?
- With a scope whose owners can confirm the objects: a few capabilities, their processes and their applications. BIAN helps compare descriptions, and the DORA chain builds on the same objects.