Our Approach
The implementation was delivered in approximately 6 months, using a phased approach designed to minimize risk and build trust with local finance teams.
Phase 1 – Design and Foundation (6 months)
Conducted a series of detailed workshops with group finance, treasury, and regional teams to define the target Net Interest Income (NII) model, including product structures, rate types, and reporting requirements.
Analyzed existing Excel models, ALM systems, and core banking data to design a standardized dimensional model and driver-based framework within OneStream.
Defined the strategy for handling multiple interest rate types (8–9 types), including:
- Identification of rate sources
- Handling different frequencies (daily vs monthly)
- Designing transformation logic
Designed and established the data architecture:
- External database for rate staging
- Mapping across product, region, scenario, and time
Agreed a phased delivery roadmap focusing on:
- Core NII calculations
- Foundational reporting
- Advanced analytics (Cost of Funds and Transfer Pricing) in later stages
Phase 2 – Build and Integration (7 months)
Configured OneStream cubes to support:
- Multi-entity
- Multi-region
- Multi-currency
- Driver-based NII calculations
Implemented data integration:
- Loaded actuals from core banking and GL systems
- Integrated balances and volume data
Developed advanced interest rate integration framework:
- Built external database to store rate data
- Developed custom Connect Business Rules to fetch and transform rates
- Converted daily rates into monthly usable formats
- Loaded structured rates into the cube
Implemented complex business rules to:
- Dynamically select appropriate rates
- Apply product and region-specific logic
- Enable scenario-based calculations
Recreated and enhanced reporting within OneStream, including:
- Net Interest Income reporting
- Cost of Funds (Scenario vs Scenario and Period over Period)
- Transfer Pricing (Scenario vs Scenario and Period over Period)
Phase 3 – Parallel Run and Go-Live (5 months)
Executed multiple parallel cycles with OneStream running alongside legacy Excel-based processes.
Used differences identified during parallel runs to:
- Fine-tune mapping rules
- Improve data quality
- Optimize complex rate calculation logic
Validated outputs across:
- Products
- Regions
- Scenarios
Trained finance, treasury, and regional teams focusing on:
- Data submission
- Validation processes
- Report consumption
Successfully transitioned to full production with OneStream as the single source of truth.
Post go-live, continued stabilization ensured:
- Smooth user adoption
- Optimized performance
- Enhanced reporting based on business feedback
The solution was designed to centralize data, standardize calculations, and provide full transparency into NII drivers