XBRL data modelling for government departments

1. Steven Baker DecisionSoft Ltd http://xbrl.decisionsoft.com/ XBRL data modelling for government departments

2. Introduction • DecisionSoft Ltd: • A background in XML data modelling and processing, • A leading role in creating the XBRL Specification, • Five years’ experience implementing online XML and XBRL processing systems, particularly for government   • Agenda: • Common and unique issues • Data modelling above the taxonomy • Capturing requirements • Taxonomy implementation • Versioning and metadata

3. Common issues • “Where do we start?” • Business experts may have little or no XBRL expertise • Standard taxonomies exist or are in draft: • http://www.xbrl.org/FRTaxonomyIndex/ • Comprehensive taxonomies are typically large • IFRS about 3200 items • UK GAAP about 3300 items • Rationalisation of requirements

4. Unique issues • UK Inland Revenue (HMCR) • Cannot mandate the corporation tax calculation • A company must be able to submit its own calculation with its own choice of data items • UK Companies House • Simple accounts using few items • Existing taxonomies excessively large • UK Financial Services Authority • Integration of similar requirements from 10 different perspectives • Many unique requirements (EG: staff training)

5. Modelling above the taxonomy • Not “what do we need in the taxonomy?” • But “what do we need reported?” • Free the reporting requirements from technological considerations • Enable business experts to lead the requirement • Creating the discoverable taxonomy set to meet the requirement should be the last step

6. An approach to capturing data • Define a robust process • Who knows the requirement? • How can they express it? • How do we transfer that requirement into XBRL? • Identify tools to support the process • Leverage existing skills • Usually use spreadsheets

7. A data capture process: • BA identifies the data items required • BA identifies the constraints upon and between items • BA evaluates how the requirement relates to other departments and standards efforts • Applicability of IFRS/UK GAAP • Review process • Must be BA-friendly • Business sign-off of items and rules, • Not taxonomies • Taxonomy implementation quality is a technical issue

8. Versioning and metadata: • Metadata • Data about data • Version numbers, author, publisher ... • Options: • Extend XBRL to encompass the required metadata • Put metadata in a higher-level model from which we generate taxonomies and documentation • Version control essential • Mechanism must be simple and unambiguous

9. Example spreadsheet

10. QA Spreadsheet model of business data Taxonomy schema Intermediate data structures (XML and other) Taxonomy linkbases Generation Generation Documentation (HTML, PDF …) Implementing the model:the Inland Revenue approach Business experts Published material

11. Conclusion • Process before tools • Reporting requirements before taxonomy creation • Business experts should not have to learn XBRL • Taxonomy creation is the last phase of the overall process