Provisional Translation

Principles for Model Risk Management

November 12, 2021
Financial Services Agency of Japan

Contents
I.

Objective .................................................................................................................................................. 2

II.

Scope and Application ............................................................................................................................. 3
1) Scope of a Financial Institution ............................................................................................................ 3
2) Scope of a “Model” .............................................................................................................................. 33) Application ........................................................................................................................................... 4

III. Definition ................................................................................................................................................. 4(a) Model .................................................................................................................................................. 4(b) Model Risk .......................................................................................................................................... 4
IV. Key Concepts of Model Risk Management .............................................................................................. 5
1) The Three Lines of Defense .................................................................................................................. 52) Model Life Cycle ................................................................................................................................... 63) Risk-Based Approach ............................................................................................................................ 6
V.

Principles for Model Risk Management ................................................................................................... 7
Principle 1 – Governance ......................................................................................................................... 7
Principle 2 – Model Identification, Model Inventory, and Model Risk Rating ......................................... 8
Principle 3 – Model Development ........................................................................................................... 9
Principle 4 – Model Approval................................................................................................................... 9
Principle 5 – Ongoing Monitoring .......................................................................................................... 10
Principle 6 – Model Validation ............................................................................................................... 10
Principle 7 – Vendor Products and Use of External Resources .............................................................. 12
Principle 8 – Internal Audit .................................................................................................................... 121

I. Objective
Financial institutions have been extending the use of models to support their decision making, driven bytechnological advances and increasing broadness and complexity in their activities. By presenting
simplified representations of reality, models provide information that aid decision making in wide-ranging
activities from business and risk management to compliance. A model, however, intrinsically entails agreat deal of simplifications and assumptions. Modelling involves different possible choices ofmethodologies and assumptions, which could significantly alter the output of the model. Models may
even contain fundamental errors or be used inappropriately, and changes in the environment may turn aonce appropriate model into an obsolete one, resulting in the misuse of the model.
All of these give rise to the risk of inaccurate or misinformed decision making, consequently causing a
potential material damage on a financial institution's earnings, financial positions, or reputation. As wellas bringing about a potential merit in improving decision making, models present such risk (i.e., modelrisk) to financial institutions. Adverse consequences arising from a model could have far-reaching impacts
beyond the financial institution using the model; they may even result in system-wide financial instability,
for example, where the use of improper models could cause market-wide underestimation andaccumulation of risk, ultimately followed by a sudden market reversal.
If problems arising from models were to affect regulatory reporting or inputs to supervisory decisions, theintegrity of financial regulation and supervision could be seriously undermined. This is particularly
relevant for capital and other regulations where financial institutions’ internal models are used for
determining their own requirements. The need for adequate controls on such internal models has long
been recognized in the regulatory community: international standard setting bodies, such as the BaselCommittee on Banking Supervision, and national supervisory authorities, including the Financial Services
Agency (FSA), have been requiring the financial institutions to effectively manage the risk arising from theinternal models in question, as a precondition for the use of the model for regulatory purposes.
However, given the extent to which models pose the risk of wide-ranging adverse consequences, financial
institutions need to manage the risks stemming from all sorts of the models, regardless of whether themodels are used for regulatory purposes. The need for comprehensive model risk management is gaining
greater significance in light of the pervasive use of models in almost every aspect of financial institutions’activities. While models for previous decades have been extensively used in pricing/valuation of financial
products and risk measurement (e.g., credit, market, and operational risk), more recently models havebeen finding their ways in broader areas. To name a few, provisioning, anti-money laundering (AML), fraud
detection, and algorithmic trading are becoming increasingly model-based. Those models are often
harnessing the technological advancements, such as increasing computational power and development
in methodologies of machine learning and artificial intelligence.

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The elevated uncertainty surrounding financial institutions has also heightened their need to manage
model risk. Many of the models are designed to predict the future based on the past or estimate anunobservable object from what has been observed. The Covid-19 pandemic and the subsequenteconomic and market dislocation have reminded us of the fact that observed patterns in the past would
not necessarily hold in the future, highlighting the nature of the risk intrinsic to models. Effective andproactive model risk management is the key to exploiting the opportunities provided by the technologicaladvancements in the highly uncertain environment.
This document is intended to clarify the FSA’s approach to model risk management, thereby catalyzing
further development of the model risk management practices in the industry. The FSA is articulating its
expectation as a list of principles rather than prescriptive rules, acknowledging the evolving nature ofmodel risk management practice, while being mindful of the fact there would be no one-size-fits-all
approach.

II. Scope and Application
1) Scope of a Financial Institution
This document is relevant to a financial institution with systemic importance, namely:


G-SIBs (Global Systemically Important Banks) headquartered in Japan;



D-SIBs (Domestic Systemically Important Banks) designated by the FSA; and

Foreign G-SIBs’ subsidiaries in Japan that have obtained approval from the FSA on the use of a model
for regulatory purposes.

For the purpose of this document, these financial institutions are collectively referred to as “firms.” Where
warranted, the FSA may expand the scope of the application in the future.

2) Scope of a “Model”
Model risk management described in this document covers a broad range of models, without limiting its
scope to particular model categories. For example, the scope of a model could include, but is not limited
to, models used for pricing, risk quantification (credit risk, market risk, etc.), AML, and market surveillance.
This document is based on the view that risk should be managed for all sorts of models, as long as themodels present risk. It should also be noted that this document is not for the purpose of providing
guidance on the management of a particular model, but for setting out a general framework tocomprehensively manage the risk arising from any kind of models.

33) Application
In building and enhancing a model risk management framework, firms should establish appropriate
prioritization. The build-up of a comprehensive model risk management framework requires substantial
time and effort. Accordingly, firms may take roll-out approaches, such as starting from models that
potentially present material risk or from areas of higher priorities in terms of effectiveness, followed by
an expansion of the coverage. When adopting a roll-out approach, firms are expected to do so with anappropriate prioritization based on the potential risk of the model and their tolerance to model risk.
The FSA’s supervision and monitoring of model risk management focuses more on the functioning of themodel risk management framework as a whole, rather than checking compliance with each element of
the principles in isolation. Firms may customize the practical application of the principles in a mannerconsistent with the risk profile, the extent of the model use, the complexity of the models used, and theoverall risk management framework of the firm. Firms are expected not only to build a framework but
also continue to ensure its effectiveness through engagements of the board of directors and the senior
management.

III. Definition
For the purpose of this document, the terms “model” and “model risk” are defined as follows.

(a) Model
The term “model” refers to a quantitative process or a system of quantitative processes that apply
theories and assumptions to process data into an output(s) such as estimates, forecasts, scores orclassification. Models include a quantitative process whose inputs or outputs are wholly or partiallyqualitative or whose inputs are based on expert judgements.

(b) Model risk
The term “model risk” refers to the potential for adverse consequences resulting from misinformed
decision making based on inappropriate or misused models. Model risk could result in deteriorationin the prudential position, non-compliance with laws and regulations, or damages to the firm's
franchise. Generally, model risk occurs because of: (1) inaccurate output resulting from fundamental
errors of a model when viewed against its intended use; or (2) inappropriate use of a model, which
includes the use of the model outside its intended use or beyond the model’s limitation.
Uncertainty is a key characteristic of models. Whereas modelling involves various choices ofmethodologies and assumptions, the output of a model is highly sensitive to the choices made (i.e.,
uncertainty from modelling choices). Furthermore, the output of a model is an estimate of something4not directly observable, such as a forecast and parameter estimate, the nature of which inevitably entails
uncertainty (i.e., uncertainty from the nature of an output). These uncertainties bring about thepossibilities of erroneous decision making, thereby giving rise to model risk.

IV. Key Concepts of Model Risk Management
1) The Three Lines of Defense
A key to sound model risk management is to establish a framework to ensure effective review andchallenge. This should be grounded on the risk culture that welcomes challenge, transparency of andhealthy skepticism toward models, and efforts not to let models be “black boxes.”
As in other risk management, different roles of model risk management can be classified into the ThreeLines of Defense (the Three Lines Model) as the fundamental framework for ensuring an effective review
and challenge. In a model risk management framework, the Three Lines of Defense could typically takethe following forms:


The first line of defense (“1LoD”) consists of units or individuals who are responsible for theownership of models or have a direct stake in model development or usage (e.g., model owners,
model developers, and model users).



The second line of defense (“2LoD”) consists of units or individuals that control the model risk via
review and challenge to the 1LoD. Their roles include, but are not limited to, the maintenance of themodel risk management framework, the independent oversight of overall model risk and compliancewith the firm’s policies, and independent validation of models.



The third line of defense (“3LoD”) consists of internal audit functions that assess the overall
effectiveness of the model risk management framework of the firm.

In presenting the principles for model risk management, this document puts an emphasis on the ThreeLines of Defense as a way to promote effective review and challenge. Firms have various ways to design
their organizational architecture in terms of the Three Lines of Defense and assign roles andresponsibilities to each of the lines. There may also be cases where a complete separation of defense lines
is not practicable. Regardless of the model risk management framework that firms adopt, they should
consider how to ensure that an effective review and challenge takes place in their framework.

52) Model Life Cycle
Effective review and challenge should be ensured in every step of a model life cycle, a process along whichmodels evolve through the passage of time – from identification of models to risk rating, development,
use, change, and exit. For the purpose of illustration, this may take the following steps:

A firm defines and identifies “models” – the scope of model risk management. Models are recorded
in a comprehensive “model inventory,” a set of information on all models the firm has identified.

Each model is assessed for its risk and assigned a risk rating. Model risk ratings form the basis of therisk-based approach to model risk management and the key determinant of the level of controls forindividual models (e.g., rigor and frequency of validation).



In the development process, comprehensive model documents are developed. This is to ensure thatmethodologies, assumptions, and limitations of the model are sufficiently transparent to stakeholders.



Prior to their official use, models are tested by the 1LoD and independently validated and approvedby the 2LoD.



After a model goes into use, the model undergoes ongoing monitoring by the 1LoD and revalidationby the 2LoD. These are carried out to evaluate whether the model is actually performing as intended.
The 2LoD has the authority to restrict or reject the use of the model when material deficiencies are
identified.

When material changes are made to a model, additional validation is carried out on the model as
needed.

The 2LoD assesses the overall model risk of the firm. The results of model risk assessments arereported to the board of directors.

The 3LoD, the internal audit function, assesses the overall effectiveness of the model risk
management framework of the firm.

All of the processes above are articulated in policies and procedures, and outputs are documented ateach step.

3) Risk-Based Approach
The risk-based approach is essential for effective model risk management. For the purpose of thisdocument, the risk-based approach refers to assessing the risk of models, managing and mitigating therisk informed by the assessment.
Where firms identify high risk for certain models, they should appropriately address and mitigate the risk
as needed. If a model risk is identified as low, they may take actions accordingly. This will enable firms toefficiently allocate resources and effectively mitigate the model risk. The risk-based approach is not only

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about individual models. Firms should also take into account the risk of models in the aggregate (e.g.,interdependence of different models) in their model risk management and address the risk appropriately.
The risk-based approach should be aligned with the firm’s tolerance for model risk. Firms should have athorough understanding of their own model risk and mitigate the risk effectively to an acceptable level.

V. Principles for Model Risk Management
In building and implementing a model risk management framework, firms should have regard to thefollowing principles:
Principle 1 – Governance. The board of directors and senior management should establish a frameworkof comprehensive model risk management.
1.1. Board of Directors and Senior Management Responsibilities
The board of directors and senior management should establish a robust framework ofcomprehensive model risk management, as part of the firm’s overall risk management framework.
The board of directors may delegate its responsibilities to execute and maintain a model risk
management framework to senior management or relevant committees. In the same manner as forother risk stripes, the overall model risk and compliance with the policies should be periodicallyreported to the board of directors.
1.2. Model Risk Management Framework
The model risk management framework should be commensurate with the firm’s characteristics, risk
profile, nature of model risk, and tolerance for model risk. It should also be on a group-wide basis
and an appropriate level of consistency should be sought across entities, regions and jurisdictions.
The model risk management framework should also be built upon due consideration on soundindustry practice and lessons learned from incidents of model risk management failure inside oroutside the firm.
1.3. Policies and Procedures
Firms should set the policies and procedures to formalize the model risk management framework
and activities. Policies and procedures should cover all aspects of model risk management, including
model definition, roles and responsibilities, model inventory, model development, implementation,and model validation.

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Firms should also document the results produced by each process in the model risk management
activities. While the required level of documentation depends on the purpose of the document, theyneed to ensure that documentation is sufficiently detailed and granular in light of the purpose sothat the necessary information is clearly communicated to the stakeholders.
1.4. Roles and Responsibilities
Firms should clearly articulate the roles and responsibilities of relevant stakeholders in model risk
management. Whereas the roles and responsibilities vary depending on the model risk management
framework of the firm, these should include: (i) ownership of models, and (ii) control of model risk
by independent parties:(i)

For each model, a firm should designate a “model owner,” a unit or an individual who isaccountable for the use and performance of the model as part of the 1LoD.

(ii)

The risk should be controlled by a “model risk management function(s),” the 2LoD functions
responsible for the maintenance of the model risk management framework and the
independent oversight of overall model risk and compliance with the firm’s policies.

Principle 2 – Model Identification, model inventory, and model risk rating. Firms should identify models,
record them in a model inventory, and assign a risk rating to each of the models.
2.1. Model Identification
Based on the definition set out in their model risk management framework, firms should identify“models” – the scope of model risk management. Typically, the 1LoD should be responsible for
identification of models and the 2LoD should be responsible for assessment of a model and nonmodel.
2.2. Model Inventory
Firms should record information for models used, under development, or recently ceased to be used
in a model inventory. The model inventory should be sufficiently comprehensive and should containall the information necessary to support the model risk management activities of the firm. Whileeach line of business, entity, and department may maintain its own inventory, firms should maintaina firm-wide inventory and the 2LoD is responsible for the firm-wide inventory management.
2.3. Model Risk Rating
Each model in the inventory should be assessed for its risk and assigned a risk rating. Risk ratings
form the basis of the risk-based approach to model risk management and the key determinant of thelevel of controls for each of the models (e.g., rigor and frequency of validation). Whereas the8approach to risk ratings depends on the firm, the risk assessment of a model may take into accountfactors such as materiality, complexity, and usage of the model.

Principle 3 – Model development. Firms should have in place a sound model development process.
Firms should adequately develop model documents and carry out model testing.
3.1. Model Development
Firms should have a model development process in place to ensure that a model is appropriate forthe intended use, in terms of its conceptual soundness, and data quality and suitability for the model.
3.2. Model Document
In the model development process, the firms should develop a comprehensive model document. The
methodologies, assumptions, limitations, and weaknesses underlying the model should be well
documented so that each mechanism and feature of the model is transparent to the stakeholders.
Model document should be sufficiently detailed so that independent parties with the relevant
expertise (e.g., model validators) can understand how the model operates.
3.3. Model Testing
In the model development process, the 1LoD should carry out model testing before the official use
of a model. Model testing should evaluate various components and the overall functioning of themodel and assess potential limitations to determine whether the model is performing as intended.
Results of model testing should also be appropriately documented.

Principle 4 – Model approval. Firms should have a robust process of model approval at various stagesof a model lifecycle, e.g., at the inception, material changes, and revalidation of a model.
4.1. Model Approval
Prior to its official use and material changes of a model, the model should be subject to validationand internal approval by the 2LoD. Where a model undergoes revalidation, the model should beinternally approved for continued use. A model approver should have the authority to grant a
conditional approval (e.g., an approval with restriction on the use of the model) or reject the use of
the model.

94.2. Exception to Model ApprovalFirms may have a process for exception of model approval. Where a firm allows exceptions to use amodel without model approval, this should be temporary and subject to rigorous control by the 2LoD.
Such exceptions should be commensurate with the risk of the model.

Principle 5 – Ongoing monitoring. After a model goes into use, the model should undergo ongoing
monitoring by the 1LoD to confirm that the model is performing as intended.
5.1. Ongoing MonitoringOnce a model goes into use, the model should undergo ongoing monitoring. Ongoing monitoring istypically conducted by the 1LoD and aims to confirm on a regular basis that the model is performing
as intended.
While a firm verifies that a model performs as intended at inception, the model may subsequently
experience deterioration in its performance, due to changes in products, business activities, market
conditions or any other circumstances. Ongoing monitoring plays an essential part in evaluating if theobsolescence of a model has occurred and verifying if the model needs to be modified or
decommissioned.
5.2. Approach to Ongoing Monitoring
The methods and other approaches of ongoing monitoring depend on the purpose, nature, and riskof a model. Firms should choose the appropriate approaches of ongoing monitoring to ensure its
effectiveness. Ongoing monitoring should be a documented process: the approaches (e.g., thefrequency and method) and results should be adequately documented.

Principle 6 – Model validation. As an integral element of review and challenge by the 2LoD, models
should be subject to independent validation. This includes initial validation prior to use, validation ofmaterial model changes, and revalidation after a model goes into use.
6.1. Model Validation
Models should be subject to independent validation. Model validation checks the soundness of themodel design and concept, appropriateness of the model usage, and the need for restrictions on theuse of the model. The results of model validation should be adequately documented and considered
as an input for model approval. The 2LoD should have the authority to require the 1LoD to takeappropriate remedial actions (e.g., restriction on or suspension of the model use) when material
deficiencies are identified.

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6.2. Types of Model Validation
Model validation should take place at various stages of a model lifecycle. All models should undergo
initial validation prior to their official use unless an exception set out in 4.2. is granted. Where
material changes are made to a model, the 2LoD should consider the necessity of a validation. Aftermodels go into use, the models should be subject to revalidation to evaluate whether they are
actually performing as intended.
6.3. Methods and Scope of Model Validation
The methods and scope of a model validation depend on the purpose, nature, and risk of the model,
as well as the data availability and validation type. Firms should choose appropriate approaches ofmodel validations to effectively challenge the model. Where applicable, the methods of validation
should include outcomes analysis (a comparison of outputs with actual corresponding data⁠—e.g.,
backtesting).
The scope of model validation should cover evaluation of both model designs and control activities
by the 1LoD. This may include, but is not limited to, model documentation, methodology specification,
assumption, data, developmental evidence, model implementation, model usage, and ongoing
monitoring.
6.4. Independence of Model Validation
Firms should ensure a sufficient level of independence of those who undertake model validation fromthe 1LoD. Independence may be supported by separation of reporting lines and/or incentive
structures. Whereas in some cases model validation may be carried out by the 1LoD, such validation
work should be subject to a review by the 2LoD.
6.5. The Risk-Based Approach to Model Validation
The frequency, rigor, and scope of model validation should be commensurate with the risk of themodel. In particular, the frequency and prioritization of revalidation should be consistent with therisk rating of a model, and firms should also take into account factors such as changes in theenvironment, deterioration in model performance, and restrictions of model usage.
As part of the risk-based approach, revalidation of low risk models may be carried out on a nonregular basis e.g., where there has been a material change in the environment or a sign ofdeterioration in model performance.

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Principle 7 – Vendor products and use of external resources. Where firms use vendor products orexternal resources, the firms should have adequate controls in place over the use of those products andexternal resources.
7.1. Vendor Products
As many elements of vendor models and other third-party products (e.g., data and parameters used
in a model) are often proprietary, firms are likely to have limited access to product information, suchas the methodologies, assumptions, and data. Even with these constraints, the firms should manage
and mitigate the associated risk to an acceptable level under their overall model risk management
framework.
7.2. Risk Management of Vendor Products
The risk management of vendor models and other third party products involves approaches different
from those for in-house models and products. Examples of such approaches include: selecting
appropriate vendors and products; requesting vendors to provide information as detailed as possible
so that the firm could have a better understanding of the model’s limitations and assumptions;performing model validation based on the best available information; and developing contingency
plans for cases in which vendor products are no longer available.
7.3. Use of External Resources
Where firms use external resources in executing certain activities of the model risk management (e.g.,model validation and model review), they should be able to understand and evaluate the results of
the activities performed by the external service provider. Due diligence and other control processes
associated with outsourcing should be consistent with the firm’s existing third-party risk
management framework.

Principle 8 – Internal audit. As the 3LoD, internal audit functions should assess the overall effectivenessof the model risk management framework.
8.1. Roles of Internal Audit
Internal audit functions should independently evaluate and verify whether the model risk
management framework and the practice are comprehensive, rigorous, and effective. As part of thefirm’s overall internal audit activities, findings from internal audit related to model risk management
should be documented and reported to the board of directors or its relevant committees.

Published on November 12, 202112