The ISO EXPRESS and Binary Data Project

1. The ISO EXPRESS and Binary Data Project January 2005

2. Agenda • Background • Survey of the state of the art • Requirements • Making the standard

3. Background : Need • STEP and related standard information models are written using the ISO EXPRESS language • There are standard implementation methods for Text and XML exchange of EXPRESS-driven data • There are also low level standard Java, C and C++ programming language interfaces for EXPRESS-driven data called SDAI • Based on experience in the STEP for Space TAS/NRF, Finite Element Analysis, Computational Fluid Dynamics and other fields, requirements for a more efficient exchange format have arisen

4. Background : VIVACE • Value Improvement through a Virtual Aeronautical Collaborative Enterprise • VIVACE EU project started January 2004 for four years • EXPRESS-driven Large Volume Binary Data Representation is defined as a VIVACE deliverable • Mats Lindeblad is VIVACE task leader from Volvo Aero • David Price is VIVACE technical resource from Eurostep Limited • Mats and David are proposed as the ISO SC4 Project Leader and Editor

5. Background : STEP Meetings • Mats set up initial discussions at ISO STEP in Poitiers, France October 2003 • Team has met at each of the three ISO STEP meetings in 2004 • Ft. Lauderdale : First announced meeting set out plan for Survey of technologies and requirements gathering • Bath : Reviewed technologies and requirements, created features analysis matrix • Seattle : Decided on HDF5 technology for first working draft and testing

6. Survey of State of the Art • Searched for binary data representations to find candidate technologies • Search found • ASN.1 : Abstract Syntax Notation 1 • HDF5 : Hierarchical Data Format • XML/Binary • Sun Fast Web Services • WAP Binary XML • Compact Binary XML • CGNS : CFD General Notation System • SDAI implementation by LKSoft

7. Gathered Requirements • At each of the ISO STEP meetings, requirements were gathered • 40-50 requirements have been identified • Based on requirements, a matrix of features was derived • Lists features needed by the proposed standard along with a simple priority • Measured HDF5 against those features and reviewed results in October 2004 at Seattle ISO STEP meeting • Based on this and knowledge of other candidates, those present decided HDF5 was the most suitable

8. HDF5 Technology • HDF5 is more than simple compression, contained data has structure

9. Making the Standard • The first working draft will be based on HDF5 per October 2004/Seattle decision • Assume an ISO 10303-20s series part that is a “profile” of HDF5 for use with EXPRESS • Plan should be for an open-source toolkit built on top of HDF5 that performs the EXPRESS/HDF5 mapping • Enforce EXPRESS base types, EXPRESS->HDF5 structure mapper, the mapper may need to be configured • Should this be a Engineer Object Level API for STEP APs? • A technical workshop is needed to create the working draft • A New Work Item ballot (NWI) or Preliminary Work Item project (PWI) are required by the ISO SC4 STEP procedures

10. PWI on “EXPRESS and Binary Data” • Evident industry need for complement to ISO10303-21/28Usage Domains: • Engineering Analysis, Manufacturing, Measurements and more • Represent EXPRESS-compatible data in an efficient, binary form • No standardized mapping from EXPRESS to binary exists • Support from participants representing: • Sweden, UK, US, Japan, Germany, France known • Financing: • Project Lead and Editor 2004-2007 from EU 6th FP project “VIVACE” • Mats Lindeblad • David Price • Proposed PWI for project within SC4/WG11 • Proposed to target ISO 10303 Implementation Method • Planned Project Milestones => Next slide

11. WG11: EXPRESS and Binary Data • Presentation and Discussion on Business Need for Standard • Review and Update of Gathered Requirements • Review of Potential Implementation Technologies from Survey • Defined and prioritised an initial set of features for comparison • Planned Project Milestones: • Jul 2004: PWI as SC4 Letter Ballot • Sep 2004: Release analysis of potential candidate technologies • Oct 2004 (Seattle SC4 meeting) • Decide on scope & Candidate technologies to include in CD document • Feb 2004 Release of first Working Draft for review and testing • Mar 2005 (Lillehammer SC4 meeting) • Hold walk through for ISO/SC4 community • Jun 2005: Release of CD document for ballot • Jul 2005 (Spain SC4 meeting) walkthrough and implementation reports • Fall 2005 (SC4 meeting): Hold CD ballot resolution work shop • Early 2006: Publish ISO TS document • … to be planned … • Nov 2007 : Published ISO International Standard of document(s)

12. Workshop needs • Produce a first working draft for implementors to do initial testing • Choose a subset of EXPRESS for prototyping • Not required for initial prototyping • rules/functions • abstract entity • complex numbers • Requirements • Entity and Attribute • Defined types of arrays • Enum • Select (some include both Entity and DT of array), • all simple datatypes • 3 level nested arrays of real • some redeclaration • Inverses • maybe derived and save results • lists are included

13. Workshop needs (2) • Choose a subset of EXPRESS for prototyping (2) • Structured grids? Part 50 more complex but would be in AP209 E2 • Configurability? • For each Entity.attribute specify the encoding • Simple datatype - specify the encoding at a global level • Transactions at the level of a “engineering or business object” level in the API • AP209 testing • Keith Hunten needs a higher level interface for application programmers that is even higher level than the AP209 schema • API is early bound to the schema, Keith would likely use C

14. Conclusion • Sufficient industry interest and need exists for the EXPRESS/Binary data representation standard • Good technology exists upon which to build a standard without inventing everything in ISO • Anyone with similar needs/interests is invited to participate in the standard or in implementations