Matrix Schema Tutorial

Presented at the:

IX European Banking SupervisorsXBRL Workshop & TutorialIn: ParisOn: 29th September 2008

By: Michele RomanelliMember of CEBS XBRL Network

Agenda

Introduction – What is a matrix schema

Change management approaches

A deeper view on matrix schemas

Conclusions

what business people ask for

what technical people deliver

what technical people say they’ve done

How to guarantee consistency among requirements, taxonomy and documentation ?

The problem: how to align business and technical view

• In COREP & FINREP contexts: A method to visualize a complex multidimensional taxonomy

• Based on a “matrix” where:

Row headers are the “concepts” to be reported

Column headers are the involved “dimension”

Cells determine: (i) if the dimension applies to the concept and (ii) what are the allowed/disallowed values for that dimension

What is a Matrix Schema?

An Example of a matrix schema

Column headers: Dimensions used in the template

Row headers: Primary items

Each row describes the breakdown structure of a primary item

Each cell contains a code that stands for the list of members allowed for the dimension in the primary item.

A sheet for each “extended link”

An Example of domain “sheet”

• Very “compact” format

• Useful as a tool to verify the “matching” between business requirements (normally expressed through templates) and technical implementation (XBRL taxonomy)

• understanding of COREP/FINREP taxonomies by supervised entities (hopefully) easier.

• Easy to build and to understand; for COREP & FINREP, it is automatically derived from XBRL taxonomies through a reverse-engineering software.

Main advantages

Taxonomy creation: the current path

From the business template

(presentation centric view)…

… to the taxonomy

(technical view) …

… to the matrix schema

(data centric view):

Reconciliation

Taxonomy creation: an alternative path

User view:

both business template and corresponding draft matrix schema

Taxonomy building:

no technical experts’ interpretation of business requirements

Matrix schema derived from the taxonomy

Reconciliation based on comparison between input and output matrix schemas

Change Management approaches

In the near future both FINREP and COREP need to be amended.

•Change the template only and build the taxonomy from scratch?

•What about a different approach?

Template vs. Matrix schema

• Templates are mainly concerned with the presentation layer

• Matrix schemas are mainly concerned with the data definition layer

The harmonisation should be sought at the data level

Transformations

Data structures

ReusableConcepts Taxonomy 4

Taxonomy 2

Taxonomy 3

Taxonomy 1

Matrix model: a layered, conceptual tool

• Domains (or Sets)– Example: the set of European Cities, or the set of Exposure

Classes • Members (or domain-members)

– Example: a single European city (Paris, Rome, …) or a single Exposure Class (Institutions, Corporates, …)

• Dimensions– A specific meaning of a Domain (example: the city of birth, the

city of residence, the city of work)• Measures (or primary-items)

– aspects we want to observe

Concepts in matrix model

Data Structures: Relationships among concepts

Primary Item Dimension

Domain Sub-Domain

Member

Is observed through

Is d

efin

ed o

n

Takes values in

Is a subset of

Contains Contains

hierarchies

Are

org

aniz

ed in

to

Are organized into

Building the Matrix schema

1. Think about what you want to observe: Primary Items

2. Think about break-down structures you are interested in: Dimensions

3. Ask yourself if these dimensions are new ones or existing ones; assign a name only to new ones;

4. Ask yourself which is the “general domain” of these new dimensions: is it an existing one? Do you need a new one?

Building the Matrix schema /2

5. Define members for newly created domains

6. Link appropriate dimensions to the primary item

7. Ask yourself if, in that relationship, the dimension is allowed to assume all the values of its “general domain”; if not, identify or define a sub-domain

8. Link the dimension to the general domain or one of its sub-domains as appropriate

Building the Matrix schema: complex issues

• Disallowing specific combinations

• Reporting a primary item for two (or more) different break-down structures

• Hierarchies of primary items (just for presentation?)

• Hierarchies of members (just for presentation? Or necessary to specify roll-up/drill-down operations?)

• Modelling tables with a non-evident distinction between measures and dimensions

Example of disallowed combinations and multiple break-down structures

Example of tables with non-intuitive distinction between measures and dimensions

Conclusions

• Matrix schema as a simple, conceptual tool

• Suitable to be automated

• Good chance to automatically generate the taxonomy from the matrix schema

• No reconciliation needs

• Shorter time-to-market

Questions?

Thank you

The XBRL Network of the

www.c-ebs.org

www.corep.info

www.finrep.info

Michele RomanelliE-mail: michele.romanelli@bancaditalia.it+39 06 4792 6218