Progress report on INSTAT/XML

Transcription

1 COLLECTION OF RAW DATA TASK FORCE 3 OCTOBER 2001 Doc. CoRD 057 Progress report on INSTAT/XML For information

2 Abstract This paper gives a progress report on the development of an XML version of the INSTAT message used for Intrastat by Working Group 5 of EBES/EG6. The Intrastat business domain has been modelled as a UML class diagram, and a separate UML model for the INSTAT message has been based on this. Separate models are necessary to allow the introduction of new classes and relationships for implementation purposes. An XML schema for the message has been derived from the model, using rules and guidelines developed in the project. Mapping tables of INSTAT between XML and EDIFACT have been developed. These tables are used as another sort of validation and in order to help the declarants in the implementation of XML and administration who want to migrate to XML. A MIG (Message Implementation Guideline) of INSTAT/XML has been written in order to offer to the user a detailed documentation of the Intrastat declaration in XML. The XML message has been successfully trialed in a prototype XML message generator built into a version of IDEP/CN8, and a prototype XML message analyser that can receive and import the data to a database in February IDEP/CN8 including the XML generator is now being tested by the Member States. The distribution of this package to the companies will begin in January Following the requirement that XML documents developed in EEG6 must be ebxml compliant, specifications of INSTAT/XML have been sent in March 2001 to EEG6 for approval. EEG6/WG5 continues to develop the specifications of INSTAT/XML and waits for instructions of EEG6 in order to get a standardised XML message for the Intrastat declaration. 2/7

3 Context This study is developed within the framework of the EDICOM project for to the Intrastat system relating to statistics of trading of goods between Member States. The INSTAT message is the electronic format of the Intrastat declaration. Member States and Eurostat studied this message within the EEG6/Working Group 5 (European Board for EDI Standardisation / Expert Group 6 Statistics / Working Group 5 Foreign Trade statistics). The first implementation is the EDIFACT message CUSDEC/INSTAT used by more than 50,000 traders in the European Union. Need of the XML version of INSTAT Several National Administrations (CNAs) already implemented web forms for Intrastat in the Member States. Generating Intrastat declarations in XML is an important technical extension of web forms because XML is both a browser language at declarant side and a format taken into account by more and more database interfaces at CNA side. Software developers request a common format of the Intrastat declaration in XML that they can implement in their commercial packages. Adopted approach EEG6/WG5 began this study by gaining knowledge in XML and other linked techniques by prototyping Intrastat declarations in XML and XSL. Then the group studied the business case of "Intrastat and XML". In September 2000, EEG6/WG5 studied the first XML schema of INSTAT based on the EDIFACT CUSDEC/INSTAT Message Implementation Guideline but met problems about the definition of the information. So, the group decided: ½ to build a stable data model of Intrastat, syntax neutral, in which everyone involved in the specification could share the same view of the Intrastat system; ½ to derive any specification data exchange from this model, in particular the Intrastat declaration in XML, called INSTAT XML. Class diagrams of Intrastat in UML Two models In February 2001, EEG6/WG5 validated and approved two models of class diagrams of Intrastat in UML: ½ the business world of Intrastat called "Intrastat declaration reference model"; this model is the result of validation between Member States and Eurostat and provides a reference for the development of any information systems in that domain; for implementation purposes, new 3/7

4 Change requests models can be derived from this model by adding or ignoring elements as necessary; ½ the INSTAT message implementation called "INSTAT message, implementation model"; this class diagram is derived from the "Intrastat declaration reference model"; the purpose of this model is to provide a basis for the definition of a DTD or an XML schema of the Intrastat declaration. Every change request must be approved by EEG6/WG5 before updating these two class diagrams and their version. INSTAT/XML Derivation The DTD (Document Type Definition) and the XML schema of INSTAT/XML have been derived from the implementation model in UML. The derivation between a class diagram in UML and an XML schema is not an automated but a "handcrafted" process. EEG6/WG5 examined the derivation step by step between each class, attribute and relationship of the UML model and each element, attribute of the XML schema. A set of rules and guidelines to be followed when deriving has been developed. Change requests Every change request must be approved by EEG6/WG5 before updating the XML schema or DTD of INSTAT. Mapping between XML and EDIFACT XML-EDIFACT and EDIFACT-XML mapping tables have been developed. These tables show the correspondence of each information in INSTAT/XML and in the EDIFACT CUSDEC/INSTAT message. These tables are used as another sort of validation and in order to help the declarants in the implementation of XML and administration who want to migrate to XML. Message Implementation Guideline of INSTAT/XML The Message Implementation Guideline (MIG) of INSTAT/XML is a proposal of user documentation for the Intrastat declaration in XML. This document is structured in the following six sections: ½ INSTAT XML Diagram, representing the structure of the document; ½ Description of the prologue; ½ Description of the elements; ½ Document Type Definition; ½ XML Schema; 4/7

5 ½ Example of an XML Intrastat declaration using the INSTAT DTD. These specifications take into account the following standards: ½ Extensible Markup Language (XML) 1.0 (Second Edition), W3C Recommendation, 6 October 2000; ½ XML Schema Part 1: Structures, W3C Recommendation 2 May 2001; ½ XML Schema Part 2: Datatypes, W3C Recommendation 2 May XML implementation in IDEP/CN8 IDEP/CN8 is the Intrastat Data Entry Package developed by Eurostat, set-up and distributed by the CNAs to the declarants. INSTAT/XML specifications are the basis of XML tools developed for IDEP/CN8. These tools, presented in Figure 1, are: ½ the generator producing well-formed and valid INSTAT XML messages, ½ the analyser parsing INSTAT XML and storing the data in a database. IDEP/CN8 XML generator XML declaration XML Analyzer Database Figure 1: XML tools developed for IDEP/CN8 XML Generator in IDEP The INSTAT XML Generator is integrated into IDEP/CN8 for Windows (V4.1.0) and works in parallel with the EDIFACT generator. By using a new MS Parameter it is possible to choose between XML and EDIFACT generation. For the user of IDEP/CN8 for Windows this is transparent. 5/7

6 This tool developed as a prototype in February 2001 is now integrated in the version of IDEP/CN8 being tested by the Member States. Member States will begin the distribution of IDEP/CN8 including the XML generator to the companies in January Prototype XML Analyser The INSTAT XML Analyser Prototype is intended to illustrate the feasibility and ease of implementation of an XML analyser for the CNA. The analyser prototype is a standalone tool that is capable of analysing an INSTAT XML message and storing the data it contains in an MS-Access database. The prototype consists of: 1. A DTD independent parser that verifies the XML message and stores the data in a database. The XML parser is based on SAX. 2. A reference table describing where XML elements are stored in the database (and how they are stored). The above-mentioned parser uses this table. 3. A viewer that browses the resulting database. This module is not linked to the other two modules. It is simply there to verify the results visually. The first results of the prototype suggest a very high performance in processing the XML message. This performance gain must be offset against the size of the XML message that has much increased compared to an equivalent EDIFACT message. Standardisation process ebxml is the electronic business XML working group. UN/CEFACT and OASIS joined forces in this group for developing a worldwide project and standardising XML business specifications. In February 2001, XML documents developed in EEG6 were required to be ebxml compliant. In order to cope with this requirement, the following procedure of standardisation of INSTAT/XML was agreed during the last EEG6/XML Task Force in February 2001: First action: EEG6/WG5 submitted the class diagram of Intrastat in UML, the DTD, the XML schema and an example of INSTAT/XML to EEG6 for approval at the end of March 2001: ½ EEG6/WG5 sent the documents to EEG6 program Office and Chairman; ½ EEG6/WG5 asked to EEG6 to approve the documents via a written procedure. Results: WG5 received agreements and comments of WG1 and WG4. Second action: WG5 assisted in the review of the ebxml Core Components and Business Processes catalogues. Results: EEG6 received draft versions of the Core Components and Business Processes catalogues and organised a review in March Members of WG5 participated in this review. These draft versions of the catalogues were not complete and it has been very 6/7

7 difficult for the group to understand how to use these Core Components and Business Processes in messages developed for statistics. Third action: WG5 checked that INSTAT/XML is compliant with ebxml Core Components and Business Processes and submit change requests to ebxml, if necessary. Results: Another draft and incomplete version of the catalogue of Core components was reviewed in May It has been agreed not to change INSTAT/XML relating to this catalogue and to wait for the EEG6 meeting in September. WG5 continues to prepare and improve specifications of INSTAT/XML and waits for instructions of EEG6 in order to get a standardised XML message for the Intrastat declaration. 7/7