1. Sept 06/IMechE LOTAR and the Long Term Retention of Digital Models Sean Barker, ARCS, CEng, MBCS, CITP BAE SYSTEMS Advanced Technology Centre © BAE SYSTEMS Aug 2006

2. Sept 06/IMechE Effects of Generation Change From PDES, LOTAR

3. Sept 06/IMechE The Business Issue Production Start Design CAD Obsolete CAD Forgotten Services Legal Liability Modifications 10 years2030405060 Spares © BAE SYSTEMS Aug 2006

4. Sept 06/IMechE LOTAR Focus by Objective Retention of product models for Aerospace Reuse Retain computer processable REPRESENTATION CAD - e.g. redesign PDM - e.g. configuration change... Certification and Legal Liability Chain of Evidence Digital Signatures Verification and Validation

5. Sept 06/IMechE LOTAR Focus by Level Keep Hardware out of scope Keep Data OAIS Repository Keep ModelLOTAR (EN 9300) Keep KnowledgeKIM project © BAE SYSTEMS Aug 2006

6. Sept 06/IMechE A Drawing Records, A Model Defines 200mm 150mm Drawings - Dimensions define a drawing Models - Dimensions are read from a model © BAE SYSTEMS Aug 2006

7. Sept 06/IMechE Use Representation Knowledge Presentation A set of pixels 20[W-]; W25B100W-; 98[W25BW98BW-]; W25B100W-; -W;; Knowledge Squares: Have Symmetry Corners are stress concentrations Bad for manholes Representation Ordered set of Vertices Assume algorithms for Boundaries Inside/outside Area LOTAR

8. Sept 06/IMechE LOTAR Focus by Objective Retention of product models Reuse Retain computer processable REPRESENTATION CAD - e.g. redesign PDM - e.g. configuration change... Certification and Legal Liability Chain of Evidence Verification and Validation Digital Signatures

9. Sept 06/IMechE Model Verification What Went In Is What Came Out ARCHIVE Prove we have retained the master From PDES, LOTAR

10. Sept 06/IMechE Archive Validation and Verification Design VerifyApprove Validate UseRetrieve Show the model has not changed © BAE SYSTEMS Aug 2006 Validation Properties

11. Sept 06/IMechE Smooth sampling point deviation calculation Sharp sampling point deviation calculation Cloud of points - Smooth and Sharp Points Shortest distance to imported surface Native ModelTarget Model Shortest distance to imported sharp edge Smooth Edge Sharp Edge Native ModelTarget Model Thanks to ITI, SNECMA

12. Sept 06/IMechE Face Sampling Points Example #2 CADIQ Smooth PointsCADIQ Sharp Points Thanks to ITI & SNECMA

13. Sept 06/IMechE Future More representations Systems Engineering Design Structure Matrices.... Validation properties PDM.... Virtual schema databases