Superannuation Fund Consolidation: Data Migration Across a Major Fund Merger

One of Australia's largest superannuation funds embarked on a landmark transformation to consolidate three separately operating funds — each with its own administration platform, data architecture, and operating model — into a single, unified entity. With over $100 billion in funds under management and more than one million members combined across all platforms, this represented one of the most complex and high-stakes data migrations undertaken in the Australian superannuation industry.

Desda was engaged from the outset to design and lead the data migration stream. Working across three phases over three years, our team brought deep superannuation domain expertise, technical data migration capability, and a structured delivery approach to ensure every member record was migrated accurately, completely, and with minimal disruption to the people who depend on these funds for their retirement.

$100B+

Funds under management

1M+

Members across all phases

Legacy systems consolidated

<10

Members quarantined post go-live

The Challenge

The client operated three distinct superannuation funds — each running separate registry systems, business processes, and member data stores. The fund consolidation required migrating all member, financial, and insurance data from three legacy platforms into a single modern administration system (Sonata Alta), without disruption to the millions of Australians whose retirement savings were under management.

Three source systems, each with distinct data models and migration challenges:

Acurity — the primary registry for the largest fund, serving ~800,000 heritage members in the second phase
Bluedoor — the registry platform for the third fund, requiring an intrafund transfer (IFT) migration approach
Legacy Sonata — an earlier iteration of the target platform, requiring careful data transformation to align with Sonata Alta's schema

Key Complexities

No single source of truth — member records were fragmented across three independent systems with different data definitions and quality standards
Large-scale financial data — migration required carrying 3–5 years of transaction history, open balances, insurance history, and all member notes and correspondence
Regulatory obligations — any data loss, inaccuracy, or member impact would carry significant compliance risk in a regulated industry
Phased program structure — three phases over three years, each with distinct source systems, timelines, and go-live pressures
Multiple technology and business stakeholders — coordination required across the program team, Line 2 Risk, the platform vendor (Bravura), and business product owners

Our Approach

Desda developed the Data Migration Playbook — the foundational strategic document for the entire program — which defined the migration approach, architecture, data quality strategy, and delivery model for all three phases. This playbook became the single reference for how data would be extracted, transformed, and loaded across the program.

Strategy & Playbook

Developed the Data Migration Playbook defining the end-to-end migration strategy, source-to-target architecture, assumptions, dependencies, and phase-by-phase delivery plan. Established a data quality framework addressing issues at source, during migration, and post-migration.

Source-to-Target Mapping

Mapped all data fields from each source system (Acurity, Bluedoor, legacy Sonata) to the Sonata Alta target schema. Collaborated closely with Bravura — the platform vendor — to validate transformation rules and data mapping documentation.

Data Quality Management

Implemented a multi-stage data quality strategy: resolving known issues at the source system prior to extraction, applying transformation rules during the ETL process, and establishing a mechanism to manage residual issues post-migration. Historical data requirements were designed to carry 3–5 years of transactions, insurance history, and all member notes and complaints.

Iterative Trial Conversions

Ran multiple iterative migration cycles, official trial conversions, and full dress rehearsals prior to each go-live. Each cycle produced reconciliation reports, which were reviewed by the Program data team, Insurance team, Finance team, and Desda to progressively close out data gaps.

Reconciliation Framework

Built a comprehensive reconciliation framework covering financial fields (member balances, opening balances, transactions) and non-financial fields (member demographics, insurance details, employer data). Independent data reconciliation testing was performed across 32 critical data fields between source and target systems.

Controls & Quarantine

Designed and implemented a multi-layered control framework to validate every member record before it was committed to the target system. Records failing validation rules — due to data quality exceptions, mapping gaps, or tolerance breaches — were automatically quarantined rather than migrated with errors. Each quarantined record was logged, categorised, and assigned for resolution, ensuring only clean, validated data reached the live system. Of over one million members migrated, fewer than 10 required quarantine at go-live, and all were resolved swiftly in the post-implementation period.

Governance & Assurance

Participated in weekly data working groups, Line 2 Risk reviews, and Transformation Hub briefings. Supported PwC's independent delivery assurance engagement, which reviewed and validated the data migration approach on behalf of the client's board and risk function.

Outcomes

After three years of structured, iterative delivery, the client successfully transitioned from three separate superannuation funds with disparate systems into a single, unified entity managing over $100 billion in retirement savings on a modern administration platform — with minimal disruption to its more than one million members.

Go-Live: Near-Zero Member Impact

Of over one million members migrated across all phases, fewer than 10 members were quarantined at go-live — a figure that reflects the depth of pre-migration validation
All quarantined members were identified immediately through the exception management process and resolved quickly in the post-implementation period, with no lasting impact to their accounts
The quarantine process ensured these members' records were held safely rather than migrated with errors, protecting their data integrity throughout
The go-live was executed on schedule, with the transition effectively invisible to the vast majority of the fund's membership

What Was Achieved

Three legacy administration systems (Acurity, Bluedoor, Sonata) replaced by a single modern platform, eliminating the operational complexity of running parallel systems across $100B+ in retirement savings
More than one million member records migrated across all phases, including approximately 800,000 in the second phase alone — one of the largest single data migration exercises in the Australian superannuation industry
Fewer than 10 members quarantined at go-live out of over one million migrated, with all exceptions resolved swiftly post-implementation
Independent assurance by PwC confirmed a structured reconciliation approach was in place, with all recommendations actioned prior to go-live
A robust, documented Data Migration Playbook retained by the client as an auditable record of migration strategy and decisions
Members now served by a single, consistent operating model — delivering improved service quality, reduced operational risk, and a platform for future growth

"There is a structured approach to present reconciliation results and track issues."
— PwC Independent Delivery Assurance

Independent Validation — PwC Delivery Assurance

PwC was engaged by the client to independently review the data migration approach and perform reconciliation testing across 32 critical data fields
PwC confirmed there was 'a structured approach to present reconciliation results and track issues' in place
All four recommendations raised by PwC were addressed by the program team, with three completed and one on track for completion prior to go-live
PwC's review provided the client's board and risk function with independent confidence in the data migration approach

Why Desda

Data migration in the superannuation sector is not a generic IT exercise — it requires an intimate understanding of how superannuation data is structured, regulated, and operationally consumed. Desda's consultants have spent careers in this industry, and that depth of knowledge is what makes the difference between a migration that works on paper and one that works in production.

Deep superannuation domain expertise — our team understands the data, the systems, and the regulatory context from first principles
Bespoke registry system knowledge — hands-on experience with Sonata, Acurity, and Bluedoor means we understand the quirks, edge cases, and transformation complexity of each platform
Proven delivery approach — from playbook to production, we bring structure, rigour, and accountability to every phase of the migration lifecycle
Track record at scale — Desda has helped migrate some of Australia's most significant superannuation funds, giving us pattern-recognition and risk foresight that cannot be replicated without lived experience