1 Latest Progress of the BOJ’s XBRL Project Outline and Some Empirical Feedback December, 2007...

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Latest Progress of the BOJ’s XBRL ProjectOutline and Some Empirical Feedback

December, 2007

　 Yoshiaki Wada　 Financial Systems and Bank Examination Department

　 Bank of Japan

© 2007 Bank of Japan

16th XBRL International Conference

in

Vancouver

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1. Introduction of the BOJ

TokyoMaebashi

Fukushima

Sendai

Aomori

Kushiro

Sapporo

Hakodate

Akita

Niigata

Matsumoto

KanazawaOkayama

Kobe

MatsueHiroshimaShimonoseki

Kitakyushu

Fukuoka

Nagasaki

KumamotoKagoshima

OitaMatsuyama

Kochi Takamatsu

Osaka

KyotoNagoya

ShizuokaKofu

Yokohama

Naha

　 Central Bank of Japan, established in 1882　 32 branches nationwide


Head Office in Tokyo

Head Office in Tokyo

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2 ． Monitoring Coverage of Financial Service Institutions

Major Banks

Regional Banks

Shinkin Banks

Foreign Banks

Securities Firms, etc.Bank of Japan

Importance of efficient data gathering scheme

Monitoring data from about 570 FSIs

BOJ covers about 570 FSIs and gathers various daily, weekly, monthly and annual data for monitoring.

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2003 2004 2005 2006 2007

Preparation for testing Tool and taxonomy

development

Live Use

･ Release of the Monthly B/S Taxonomy on banking a/c･ Revision of the Monthly B/S Taxonomy ･ Release of the Taxonomy Setting Tool･ Release of the Monthly B/S Taxonomy on trust a/c･ Release of the Monthly Lending Rate Report Taxonomy

3 ． Project history

Three-phase test

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4 ． The BOJ’s XBRL based reporting scheme

②D/L of necessary taxonomy set

⑤ D/L of ＸＢＲＬ data

① U/L of taxonomy set to the library

FSIs

ＸＢＲＬ③ data creation and validation

Data　creation　tool

Error-free data files

BOJ

Error-free data files

IP-VPN

Database Database

Post data validation

Taxonomy　library

Taxonomy　setting　tool

Taxo2Ta xo3

Taxo1 Taxo2

Earlier data release for users

④ U/L of XBRL data

Select the taxonomy according to the report type

Develop the taxonomy set according to the report type

Excel XBRL

Check for errors using the function of Formula-Link and correct the file

XBRLXBRL

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5 ． Features of the BOJ’s XBRL reporting scheme (1)

1 ． All necessary tools, taxonomy, and data communication infrastructure are supplied by the BOJ for free.

⇒　 After receiving the necessary taxonomy set, FSIs can promptly generate XBRL data and report it to the BOJ.

2 ． FSIs can generate the XBRL instance file, without any third-party assistance.

⇒　 Data security is improved.

3 ． By using Formula-Link, data accuracy is improved.

⇒　　Cost of data handling can be minimized both for FSIs and the BOJ.

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6 ． Review of the last 20 months of live use (1)

⇒ Our XBRL tool has worked without fatal problems.

1. No down time

⇒ The reliability of the tool and availability of the total reporting workflow were confirmed.

2 ． All FSIs submitted monthly B/S data in XBRL format ⇒ Although XBRL was not mandatory in our reporting scheme,

all FSIs submitted data in XBRL format voluntarily.

⇒ FSI’s degree of recognition of the new reporting scheme increased steadily.

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7 ． Review of the last 20 months of live use (2)

3 ． Revision and re-distribution of the current taxonomy and the release of the new range of taxonomy

⇒ The taxonomies have been revised several times due to revisions to Japanese company law or the requirement for new data.

⇒ A new range of taxonomies, such as those for monthly B/S of trust accounts and lending rate reports, was released.

4 ． Enhancement of efficiency of FSIs’ reporting work and the BOJ’s data processing

⇒ Decrease in manpower required for data reporting in the FSIs and for database operation in the BOJ

⇒ Earlier release of the accurate data to the BOJ’s data users.

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8 ． Increased efficiency in the data reporting scheme (1)

No more post data correction via telephone

Excel

Template for data input

XBRL

Taxonomy –set A

Taxonomy setting tool

Data conversion tool (X-Port)

Formula-LinkFormula-Link

Error check

Error correction

From BOJ

To BOJ

Error- free XBRL

Taxonomy –set B

Taxonomy –set C

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Changes of the BOJ’s business flow on the Monthly B/S data processing

Report deadline

day X X+1 X+2~4 X+5 X+6day X X+1

X+5 X+6

Preparation of data U/L

Data U/L and validation within DB

Data processing within DB

Data release for BOJ users

Error correction

Data validation by XBRL, prior to data submission

Reduction of post validation costReduction of post validation cost

Data validation by XBRL, prior to data submission

Reduction of post-validation cost

Old Flow

Early data release（ 2 to 4 days)

Short cut!

New Flow


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Reduction of the required part-time manpower in the BOJ’s database team


020406080

100120140160180

April

MayJ u

ne J uly

Aug.

Sept.

Oct.

Nov.

Dec.

J an.

Feb.

Mar.

(FY2

004=

100)

2004FY2005FY2006FY2007FY

XBRL went live (Feb. 2006)

Dotted line : Before XBRL

Solid line : After XBRL


Three key factors for the better performance taxonomy;

9 ． Some empirical feedback from BOJ’s XBRL Lab.(1)

Proper taxonomy size

　 Proper combination of Formula-Link and Dimensions

　 Prototyping and performance tuning with bench mark test

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Proper taxonomy size:


• Within the BOJ’s reporting business model, there is a rule which limits every taxonomy volume to a certain size, for the following reasons:

Stress-free data transformation and validation using X-Port within the limited capacity of FSIs’ PC

Smooth delivery of taxonomy to the FSIs under the limited capacity of IP-VPN

⇒　 Currently, the zipped file size of each taxonomy set is limited to 2 MB

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Importance of proper combination of Formula-Link and Dimension-Link ;


Merits• Flexibility of taxonomy design

• Reduction of items, Presentation –Link and Definition-Link

• Easier setting of concepts

Demerits

• Complicated Formula-Link setting, caused by the unavailability of relative context ID for the item

• Increased process time for data reading and analyzing for Formula-Link

Merits & Demerits of Dimensions

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6 items

Deposit123456

Hypercube1Dimension1

ⅠⅡⅢ

Dimension2ABC:Q

＊＊

＊＊

＊＊


An example of Dimensions use case (1)

Original Reporting Form Flat Taxonomy Taxonomy with full Dimensions


Increase of Complexity

＊

＊

＊

＊

＊

＊

Deposit

ＡＢＣ・・・ＱＡＢＣ・・・Ｑ

A B C ・・・ Qa Aa Ba Ca ･･･ Qab Ab Bb Cb ･･･ Qbc Ac Bc Cc ･･･ Qca : : : ･･･ :b : : : ･･･ :c : : : ･･･ :

1

2

TableⅠ

TableⅡ

TableⅢ

312　items,　no　context

Increase of Process Time

Instant & Duration

DepositTable Ⅰ

Ⅰ1AⅠ2AⅠ3A

　：Ⅰ6Q

Table ⅡⅡ1AⅡ2AⅡ3A

　：Ⅱ6Q

Table ⅢⅢ1AⅢ2AⅢ3A

　：Ⅲ5C

Others

102 items

312　concepts2　context

102 items

102 items

6 items

Sum of ＊

32 items

102 context

32 facts 17 items

17×3×2

6+17+sum of ( ＊ & ＊＊ )

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An example of Dimensions use case (2)

Observed Result of Taxonomy Bench-Mark Test


(a)

Number

of

Concepts

(b)

Number

of

Member Item other than Concepts

(c)

Number

of

Contexts

(a)×(c)

Number

of

Facts

(a+b)×(c)

Number

of

Possible

Facts

Time for Data Read to X-Port

Tome for Data

Validation by

Formula-Link

Case1*

Flat taxo 306 6 2 612 624 23 sec 3 sec

Case2*

Taxo with full DM

6 26 102 612 3264 33 sec 15 sec

Case3*

Taxo with partial DM

51 9 12 612 720 22 sec 3 sec

Test Condition;

Tool : BOJ X-Port

CPU : Pentium M 2GHz, with 2GB memory

* Case1 to 3 were build on the same reporting format. The only difference is the use of dimensions.

+ 20 items

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Number of Items affects processing time

Increased dimension’s

member items affect

processing time!!

6 ｃｏｎｃｅｐｔ s

Deposit123456

Hypercube1Dimension1

ⅠⅡⅢ

Dimension2ABC:Q

＊＊

＊＊

＊＊

＊

＊

＊

＊

＊

＊

Deposit

ＡＢＣ・・・ＱＡＢＣ・・・Ｑ

A B C ・・・ Qa Aa Ba Ca ･･･ Qab Ab Bb Cb ･･･ Qbc Ac Bc Cc ･･･ Qca : : : ･･･ :b : : : ･･･ :c : : : ･･･ :

1

2

TableⅠ

TableⅡ

TableⅢ

312　items,　no　context

　　　　　　　　　　　　　　　　　 Number of Member Items Other Than Concepts

Flat Taxo Case : 6 (=sum of ＊ ) → Taxo with full Dimensions: 26 (=sum of ＊ & ＊＊＆ 17 ）

Original Reporting Form Taxonomy with full Dimensions

17 items

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How to make an efficient Taxonomy?


Complexity of Taxonomy (i.e. Number of Possible Facts) 　

Work-load of building taxonomy

Data processing time

Optimal point !

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How to find the optimal point?

Important 3 steps


1st. Measure the Number of Possible Facts of the flat taxonomy case = Basic Index

2nd. Design the structure of taxonomy with Dimensions so that the Number of Possible Facts can be small as the Basic Index level

3rd. Make a prototype, measure its performance by bench-mark test, and tune the structure

Some new treatment should be done in the Spec Level? 19


10 ． Next steps (1)

Advancement in taxonomy design

　 Version-up of current XBRL data conversion tool

　 Design of new XBRL database

⇒　 New version of taxonomy with Formula-Link and Dimensions

⇒　 Establish the more sophisticated tuning method

⇒　 Adaptation to Windows Vista and enhancement of processing power in the core engine of the tool

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Design of XBRL Database

Issues to be solved

How to manage the relation of XBRL instance and taxonomy

How to generate consistent time-series data from different instances and taxonomies

How to utilize the XBRL meta-data for efficient data analysis

How to reduce the cost of database operations

9 ． Next steps (2)

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For further information, contact

[email protected]

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Thank you for your attention.

1 Latest Progress of the BOJ’s XBRL Project Outline and Some Empirical Feedback December, 2007...

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