Validation Services

Validation Services – Statistical Decisions

Services / Scoring

Model Validation Services

Independent, rigorous, and business-aware validation of credit scoring, rating, and risk models — aligned with the ECB and EBA regulatory framework.

Credit Risk Models IRRBB Models Liquidity Models IFRS 9 / CRR3 ECB / EBA Aligned

Regular validation of Scorecards and Rating Models is vital for the optimal functioning of decision tools. The operating environment of models is not stable — changes arise from systems, policies, processes, customer profile shifts, behavioural patterns, the economic environment, competition, and marketing initiatives.

The 2008 Financial Crisis triggered increasing supervisory scrutiny of model development and validation practices. The subsequent adoption of IFRS 9 and the full roll-out of CRR3 have further reinforced the importance of a holistic, independent, and multi-layered validation framework. Independence of the Validation Function is now a regulatory prerequisite, encompassing internal Validation Units, Internal Audit, and independent external validators.

Regulatory Framework for Model Validation

StatDec’s validation methodology is fully aligned with the current ECB and EBA regulatory framework. Institutions subject to SSM oversight must ensure validations cover both quantitative performance and qualitative governance dimensions, across all three lines of defence.

Latest — July 2025 ECB Revised Guide to Internal Models (28 July 2025)

The most comprehensive revision of the ECB’s supervisory guide since TRIM, incorporating CRR3 (effective 1 January 2025). Key validation implications for Significant Institutions:

  • Refined internal validation and audit expectations, explicitly integrated with the EBA IRB Validation Handbook
  • New section on ML models — explainability, bias testing, and higher-frequency audit for complex models
  • Senior management and management body directly accountable for model quality and ECB submission readiness
  • LGD Reference Value elevated to an active validation challenge requiring documented action when weaknesses appear
  • IRB permissions now granted at exposure class level (CRR3) — institutions must document clear model strategies
  • 3-month implementation deadline for material model changes post-ECB permission; outsourcing does not exempt from validation
  • ECB announces increase in proactive internal model investigations in areas of high supervisory attention
  • Market risk split into separate CRR2 and CRR3 chapters reflecting phased FRTB implementation
  • EBA/GL/2023/01Guidelines on Internal Model Risk Management — overarching governance, documentation, and periodic review obligations for all internal models.
  • EBA IRB Validation HandbookEBA’s supervisory handbook on IRB rating system validation, now explicitly incorporated into the ECB’s revised July 2025 Guide.
  • EBA/GL/2017/16Guidelines on IRB PD, LGD and EAD estimation — Full Validation requirements, backtesting standards, and Margin of Conservatism.
  • EBA/GL/2022/14Guidelines on IRRBB and CSRBB — model validation obligations for EVE and NII models, behavioural assumptions and stress scenarios.
  • EBA/GL/2020/02Loan Origination and Monitoring — validation of creditworthiness assessment models, including AI/ML tools used in origination.
  • CRR3 / Reg. (EU) 2024/1623In force January 2025 — selective IRB approach, revised roll-out and PPU rules, updated parameter floors and CCF treatment.

Full Validation vs. Ongoing Monitoring

Regulatory frameworks and sound model risk management practices distinguish between two complementary validation regimes. StatDec supports both with appropriate depth and rigour.

Periodic / Ongoing Validation

Annual or semi-annual performance reviews focused on stability, discrimination, and calibration accuracy. Designed to provide early warning of model drift and inform remediation decisions before a Full Validation cycle is triggered.

Components include:

  • Discrimination and rank-ordering (Gini, KS, AUC)
  • Population Stability Index (PSI) and characteristic drift
  • Calibration accuracy and backtesting
  • Exclusion and override analysis
  • Action plan tracking from prior validations

Post-Implementation Review

Conducted 6–12 months after deployment of a new or materially changed model. Verifies live performance and implementation accuracy, aligned with the ECB’s 3-month implementation deadline introduced in July 2025.

  • Implementation accuracy assessment
  • First-cycle performance benchmarking
  • Data pipeline and integration review
  • Early indicator monitoring setup

Targeted / Thematic Validation

Focused deep-dive on a specific dimension of model risk, commissioned in response to supervisory findings, audit observations, or specific business concerns.

  • Data quality and representativeness
  • Definition of default alignment (CRR3/EBA)
  • Margin of Conservatism (MoC) review
  • LGD Reference Value challenge
  • Override and exception policies

Validation Test Blocks

Validation tests are structured as independent blocks. When examined holistically, they provide a complete picture of both model health and underlying portfolio dynamics. Findings on systems, policies, marketing activities, and collections can be identified and presented as part of the validation output.

Qualitative Assessment
Quantitative Assessment
Score Inputs & Data Processing
Data Quality & Representativeness
Model Implementation Accuracy
Exclusion & Override Analysis
Definition of Default Review
Model Use & Governance Review
Documentation & Conceptual Soundness
Margin of Conservatism (IRB / IFRS 9)
Discrimination Power (Gini, KS, AUC)
Calibration Accuracy & Backtesting
Population Stability (PSI, CSI)
Concentration & Segmentation Analysis
Model Inputs Drift Analysis
Challenger Model Benchmarking
Stress Testing & Sensitivity Analysis
Long-Run Average & Downturn Estimates

Beyond Credit Risk: Non-Credit Model Validation

The regulatory validation mandate extends well beyond credit scoring. EBA guidelines and Pillar 2 requirements impose validation obligations on provisioning models, treasury risk models, liquidity models, and behavioural models integral to the institution’s risk management framework.

IFRS 9 / ECL Models
IRRBB Models
Liquidity Models
Other Risk Models

IFRS 9 ECL models carry direct P&L impact and are under increasing scrutiny from auditors and supervisors. StatDec provides independent validation covering all model components and the macro-economic overlay framework.

Stage Classification
SICR Models

Validation of Significant Increase in Credit Risk criteria for Stage 1→2 migration, including relative/absolute PD change approaches and qualitative backstop triggers.

PD / LGD / EAD
Lifetime ECL Component Models

Full validation of point-in-time PD term structures, downturn LGD estimates, and EAD/CCF models — including conversion from TTC to IFRS 9 PiT parameters.

Macro Overlay
Forward-Looking Information & Overlay Models

Assessment of macro-economic scenario design, probability weighting, and satellite models linking macro variables to PD and LGD.

Collective Assessment
Portfolio-Level & Collective ECL Models

Validation of grouping criteria, loss emergence period assumptions, and benchmarking of collective provisions against actual loss experience.

Governed by EBA/GL/2022/14 on IRRBB and CSRBB, institutions must validate models for interest rate risk in the banking book, including behavioural models critical for accurate EVE and NII sensitivity computation.

Behavioural
Non-Maturity Deposit (NMD) Models

Validation of core deposit volume stability, repricing assumptions, and behavioural maturity estimates, benchmarked against EBA supervisory outlier thresholds.

Prepayment
Loan Prepayment Models

Assessment of prepayment speed assumptions for fixed-rate retail and corporate loans, with sensitivity analysis across interest rate scenarios and credit quality strata.

Valuation
EVE & NII Sensitivity Models

Review of interest rate shock and stress scenarios (per EBA standard shocks), repricing gap methodology, and alignment with supervisory benchmarks.

Spread Risk
CSRBB Models

Validation of credit spread risk in the banking book, including spread sensitivity measurement and scenario design for securities portfolios.

Liquidity risk models underpin LCR, NSFR, and ILAAP requirements. Their validation ensures that stress outflow assumptions and behavioural parameters remain conservative and realistic.

LCR / NSFR
Regulatory Liquidity Ratio Models

Validation of inflow/outflow rate assumptions, HQLA haircut methodology, and classification of liabilities and committed facilities under stress conditions.

Stress Testing
Liquidity Stress Testing Models

Assessment of scenario design (idiosyncratic, market-wide, combined), survival horizon computation, and behavioural assumptions on deposits, credit lines, and collateral calls.

Behavioural
Deposit Run-Off Models

Validation of segmented run-off rates for retail, SME, and institutional deposits, reviewed against historical crisis observations and regulatory floors.

ILAAP
Internal Liquidity Adequacy Models

Independent review of ILAAP liquidity buffer sizing, risk appetite metrics, and models supporting internal liquidity transfer pricing.

StatDec’s validation expertise extends to the broader model inventory relevant to risk management and capital planning, including the ML-specific validation expectations introduced in the ECB’s July 2025 Guide.

Market Risk
Internal Models for Market Risk (IMA)

Validation of VaR, Expected Shortfall, and stress VaR models, including backtesting under FRTB/CRR3. Separate CRR2 and CRR3 treatment per ECB July 2025.

AI / ML
Machine Learning Models

Specialist validation of ML-based credit risk and fraud models addressing explainability (SHAP, LIME), bias testing, and governance — aligned with ECB July 2025 and EBA/GL/2020/02.

Capital
ICAAP / Stress Testing Models

Review of internal capital adequacy models, Pillar 2 add-on estimation, macroeconomic stress scenario design, and capital projection models.

Operational
Propensity & Behavioural Models

Validation of early warning systems, pre-approval propensity, customer lifetime value, and churn prediction models used in commercial decision-making.

Our Validation Approach

01
Regulatory Alignment

All validations are designed in full alignment with the ECB Guide (July 2025), EBA guidelines, and CRR3 requirements, ensuring defensible, supervisory-ready findings.

02
Business Perspective

Beyond statistical metrics, we assess whether models are being used properly, decisions are optimal, and risk estimates are fit for business purpose.

03
Customised Frameworks

Validation scope, tests, and reporting are tailored to the client’s existing framework, portfolio characteristics, and specific regulatory context.

04
Portfolio Insights

Validation outputs include portfolio-level findings — shifts in borrower behaviour, policy effects, and market changes — not just model-level statistics.

05
Independent External Validator

As a specialist external validator, StatDec satisfies the independence requirement under EBA/GL/2023/01 for institutions requiring a third validation layer.

06
Actionable Outcomes

Every validation concludes with a structured, prioritised action plan — with best practice recommendations extending beyond model changes to governance and process.

Commission an Independent Validation

Whether you require a Full Validation under the ECB’s July 2025 Guide, ongoing monitoring, or validation of IFRS 9, IRRBB, or Liquidity models, StatDec delivers expert, independent assessments of the highest quality.

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