LOTAR High Integrity CAD Data for Aerospace Sean

LOTAR High Integrity CAD Data for Aerospace Sean Barker BAE SYSTEMS Advanced Technology Centre DPC: Designed to Last - 1 BAE SYSTEMS July 2010 All rights reserved

BAE SYSTEMS BAE Systems is the premier global defence, security and aerospace company delivering a full range of products and services for air, land naval forces, as well as advanced electronics, security, information technology solutions and customer support services. Key Facts - 2 nd largest global defence company - 107, 000 highly skilled people - Global capability - Customers in over 100 countries - Annual sales exceed £ 22 billion - More than 100 new inventions every year DPC: Designed to Last - 2 BAE SYSTEMS July 2010 All rights reserved

Focus The retention of CAD models as – Retention of Business Knowledge Not – Technology for bits and bytes Key Question – How do we reliably retain detailed design knowledge encoded in CAD models? The question is about how a business uses IT to capture design knowledge, rather than IT itself DPC: Designed to Last - 3 BAE SYSTEMS July 2010 All rights reserved

Contents • • Drawings v. Models What is LOTAR? Validation and Verification Knowledge Retention DPC: Designed to Last - 4 BAE SYSTEMS July 2010 All rights reserved

Drawing v. Model Drawing PASSIVE, to display An Image tool translate bytes into pixels Model ACTIVE, to manipulate & query For a line, a CAD tool knows how to: • calculate its length • find the tangent • calculate where it crosses another line • etc DPC: Designed to Last - 5 BAE SYSTEMS July 2010 All rights reserved

Models Represent Knowledge Presentation (drawing) Representation (model) A set of pixels • 20[W-]; • W 25 B 100 W-; • 98[W 25 BW 98 BW-]; • W 25 B 100 W-; • -W; ; Rationale (knowledge) Ordered set of Vertices Assume algorithms for • Boundaries • Inside/outside • Area Squares: • Have Symmetry • Corners are stress concentrations • Bad for manholes LOTAR DPC: Designed to Last - 6 BAE SYSTEMS July 2010 All rights reserved

A Drawing Records, A Model Defines 200 mm 150 mm Drawings - Models - Dimensions define a drawing Dimensions are read from a model DPC: Designed to Last - 7 BAE SYSTEMS July 2010 All rights reserved

A Brief History of CAD Manual Drawing Computer as Electronic pencil Automated redrawing after small changes Part shape is modelled to produce drawings more easily Geometry Modelling Part model includes shape, materials, tolerances 1960's 1970's 1980's Product Modelling 1990's 2000's DPC: Designed to Last - 8 BAE SYSTEMS July 2010 All rights reserved

The Electronic Design World Requirement Functional Design n ut np uma i h om fr n ut np uma i h om Optimisation Shape Design fr ut an inp um h om fr Design is direct input to manufacture - Drawing is not the basis of manufacture t resul n ma to hu FE Analysis NC Part Program t resul n ma to hu Automated metrology t resul n ma to hu Operational Use Design is direct input to inspection - Drawing is not the basis of inspection DPC: Designed to Last - 9 BAE SYSTEMS July 2010 All rights reserved

Contents • • Drawings v. Models What is LOTAR? Validation and Verification Knowledge Retention DPC: Designed to Last - 10 BAE SYSTEMS July 2010 All rights reserved

An Example of Generation Change DPC: Designed to Last - 11 BAE SYSTEMS July 2010 All rights reserved

What is LOTAR? Joint European/US standard for best practice in long term data retention in the aerospace industry Driver for civil sector: Electronic certification by FAA and EASA Site web : http: //www. prostep. org/lotar/ DPC: Designed to Last - 12 BAE SYSTEMS July 2010 All rights reserved

LOTAR and Application Knowledge • NOT - is the data unchanged by the repository? • BUT - are BOTH the data AND the algorithms unchanged? DPC: Designed to Last - 13 BAE SYSTEMS July 2010 All rights reserved

LOTAR on a Page LOTAR identifies use cases for CAD Assemblies, PDM, etc LOTAR adds use case quality checks to OAIS Repository LOTAR sets use case integrity checks on recovered data DPC: Designed to Last - 14 BAE SYSTEMS July 2010 All rights reserved

LOTAR – Current status 1 Structure 2 Requirements (harmonised AIA ASD-STAN) 3 Fundamentals and Concepts 4 -7 Other basic Parts 10 -15 OAIS Processes 20 Preservation Planning 100 CAD Fundamentals 110 CAD Explicit Geometry 115 CAD 3 D Assembly Structure 120 CAD 3 D Explicit Geometry with PMI 200 Product Data Management Key Issued Balloted Developing DPC: Designed to Last - 15 BAE SYSTEMS July 2010 All rights reserved

Contents • • Drawings v. Models What is LOTAR? Validation and Verification Knowledge Retention DPC: Designed to Last - 16 BAE SYSTEMS July 2010 All rights reserved

STEP Standard for the Exchange of Product Data – – ISO 10303, in many parts, since 1980's AP 203 & AP 214 - standards for CAD Link geometry to product meta-data Provides Validation Properties • Surface Area • Volume • Cloud of Points Standard will be stable over the long term Provides "hooks" for validation and verification DPC: Designed to Last - 17 BAE SYSTEMS July 2010 All rights reserved

Validation – Cloud of Points what comes out is what went in Validate that the new software reads the old data correctly Example – CAD 3 D models and Cloud of Points: Are points still on the surfaces and edges? Image courtesy ITI & SNECMA DPC: Designed to Last - 18 BAE SYSTEMS July 2010 All rights reserved

Contents • • Drawings v. Models What is LOTAR? Validation and Verification Knowledge Retention DPC: Designed to Last - 19 BAE SYSTEMS July 2010 All rights reserved

Human v Computer LOTAR preserves models – but what about the knowledge needed to understand them? In the 1940's Geoff Wallace of the Ministry of Supply at Creekmoor, Poole had a problem Spitfire parts made in the US - right-handed parts came back left-handed - why? First Angle Projection Third Angle Projection What is the difference between the two drawings? DPC: Designed to Last - 20 BAE SYSTEMS July 2010 All rights reserved

Human v Computer - Dimensions and Tolerances Does the leader line end at a point in space, or point to a feature? What is a feature? Is the text simply lines on a drawing? A string of symbols? An assertion about a diameter What happens to the text when I move my view point? Image courtesy PDES Inc DPC: Designed to Last - 21 BAE SYSTEMS July 2010 All rights reserved

Human v Computer - Driving dimensions 55 50 30 115 Which dimension to shrink? 35 50 30 50 55 30 30 55 50 10 Dimensioning is driven by design rational DPC: Designed to Last - 22 BAE SYSTEMS July 2010 All rights reserved

Conclusions • LOTAR – a business standard for long term model sustainment – the business defines the key characteristics – it is not about IT functionality • • The problem is sustaining models, not drawings A model is data PLUS algorithms LOTAR validates AFTER data is read by the software There are open issues that need research: – Validation – Rationale integration with models – Knowledge recovery from old data DPC: Designed to Last - 23 BAE SYSTEMS July 2010 All rights reserved

backup DPC: Designed to Last - 24 BAE SYSTEMS July 2010 All rights reserved

Why Sustain Data? Time between CAD Versions: 6 months Life of CAD System: 10 years Life of Product: 70 years + time Production Services Spares Modifications CAD Obsolete CAD Forgotten Legal Liability 10 years 20 Image courtesy PDES Inc 30 40 50 60 DPC: Designed to Last - 25 BAE SYSTEMS July 2010 All rights reserved