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

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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

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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

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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

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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

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HDF5 Technology

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

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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-gtHDF5
  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

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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 gt Next slide

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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)

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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

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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

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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