STEP ARCHITECTURE Module 4 Estimated Viewing Time: 60 Minutes

1. STEP ARCHITECTUREModule 4Estimated Viewing Time: 60 Minutes STEP MANAGEMENT OVERVIEW

2. Sponsored By The NationalInstitute of Standards & Technology Developed Under Contract by: Product Data Integration Technologies, Inc. 100 W. Broadway, Suite 540 Long Beach, CA 90802

3. Topics for This Module Data Architecture • STEP’s underlying semantic “backbone” Representation Forms • The EXPRESS Modeling Language Document Architecture • The structure of the STEP Standards documents Application Protocols • An introduction the implementable portion of STEP

4. Design Principles behind STEP • Incorporate meaning of data into a data structure • Provide a formal and computer sensible data modeling language • Utilize a development process that allows subject area experts to focus on the meaning of the data to be exchanged • Retain independence of data (enterprise information) from implementation types (a single representation (or model) can be used across all types)

5. Data Architecture: Shareable and Extensible • The conceptual data models represent a consensus view of the data semantics commonly used in product data subject areas and understood by a category of application systems • The reuse of general ideas within different contexts is supported by levels of semantic abstraction (encapsulation) • The models are integrated into a single, conceptual schema using a consistent data architecture • The semantics are partitioned to permit extension and pruning (modular design)

6. STEP Data ArchitectureSimple Example Product Aircraft: B-2 Bomber, engine, radar system Formation (version) B-2 Bomber prototype design 1 As-Design definition, As-Maintained definition, Functional-design definition Life cycle definition Properties Shape, material property, design requirement, functional characteristics Representation Geometric model, chemical composition, textual description, measurements, numbers`

7. STEP Data ArchitecturePopulation Example Properties shape length=3 mm width=4.5 mm Parametric dimensional representation, geometric representation Representation high-performance aerodynamic shape Descriptive Geometry reference to a document Raster Image Wireframe Surface Solid curves and points planar surfaces, free form surfaces boundary rep, constructive solid geometry

8. STEP Data ArchitectureSemantic Extensions Examples Printed_circuit_assembly Product building_element Semantic Extensions Examples piping_component Formation (version) part_library definition Life_cycle definition functional_design definition manufacturing_planning definition

9. STEP DATA Architecture Product Examples of capabilities for the description of Properties and Representation Formation (version) Life cycle definition Shape Material Properties Parametric Surface Finish Representation Descriptive Structural Geometry Behavioral Raster Image Wireframe Surface Solid

10. EXPRESS • Declarative object-like, Pascal-like, information modeling language • Used to specify data semantics and structure for Data Architecture and other STEP specifications • Entities, Types, Rules and Functions are basic constructs of EXPRESS • Logical collections of data constructs are partitioned into Schemas • Formal syntax permits automated processing of EXPRESS models

11. product_version The EXPRESS Language of product product Graphical Representation SCHEMA product_definition; TYPE identifier = STRING; END_TYPE; TYPE label = STRING; END_TYPE; version first_equivalent of product product_definition second_equivalent first_related _definition second_related _definition product_category product_definition _equivalence product_definition _relationship SET [1:?] subcategories ENTITY product_category; name : label; subcategories : OPTIONAL SET [1:?] OF product_category; of_product : product; END_ENTITY; ENTITY product_version; ident : identifier; name : label; description : OPTIONAL text; of_product : product; END_ENTITY; Textual Representation

12. Application Protocols and Abstract Test Suites Parts 200+ & 300+ Conformance Methods Part 31 Conformance Testing Methods: General Concepts Parts 32-35 Reqs for Test Labs & Clients Test Methods for File & Data access method Description Methods Part 11 EXPRESS Framework Part 13 STEP Development Methodology Application Interpreted Constructs Parts 500+ Integrated Resources Application Resources Parts 101+ Generic Resources Parts 41-99 Implementation Methods Part 21 Physical File, Parts 22-29 Data access method STEPDocument Architecture

13. Integrated Resource Parts • General purpose product data specifications written in EXPRESS • Provide the "building blocks" or "vocabulary" for Application Protocols • Two classes: • General Resources (40 series) • Application Resources (100 series)

14. Generic Resources Product Description Fundamentals Shape Representation Structure Presentation Geometric Models Application Resources Draughting Finite Element Analysis Development of the Integrated Resources

15. Application Protocols • An Application Protocol defines the usage of STEP Product Data for a given application context. • An Application Protocol represents a measurable and shareable subset of STEP capability that is expressed in an industry’s or discipline’s terminology.

16. Generic Resources Product Description Fundamentals Shape Representation Structure Presentation Geometric Models Draughting Finite Element Analysis Application Resources Application Protocol Concept Required STEP Resources Application Protocol Requirements Mapping

17. Generic Resources Product Description Fundamentals Shape Common Resources Representation Structure Presentation Geometric Models Draughting Finite Element Analysis Application Resources Application Protocol #2 Requirements Application Protocol #1 Requirements Mappings Application Protocols ShareCommon Resources

18. Application Protocols: Re-use and Specialize Common Constraints -- Example A s s e m b l y S c h e m a t i c P i p i n g A s s y _ S t r u c t u r e S c h e m _ D i a g r a m P i p i n g _ R u n ( N e t w o r k Structure) ( N e t w o r k Structure) ( N e t w o r k Structure) N e t w o r k Structure M a t e r i a l V e r s i o n S h a p e P r o d u c t I d e n t i f i e r S p e c i f i c a t i o n Integrated Resources

19. AAM ARM AIM Elements of an Application Protocol • Application Activity Model A function model that describes the activities and processes of defined application context domain. This is a requirement document. • Application Reference Model An information model that describes the information requirements and constraints for an application context area. The model uses application-specific terminology and rules that are familiar to experts in the application area. • Application Interpreted Model An information model that describes the STEP data structures required for functional equivalence with the application contexts' AAM's and ARM's. • Conformance Classes Descriptions of the valid populations of the file, which serve to define conformant uses of the AP. AP Test Purposes

20. STEP Exchange Format • Part 21: Clear text encoding of the exchange structure • Is the algorithm used in the exchange of data via a physical file format. • Result is a sequential file of ASCII characters described in a computer-interpretable form. • Defines the mapping from EXPRESS into the exchange file: ENTITY product_category; name : label; subcategories : OPTIONAL SET [1:?] OF product_category; of_product : OPTIONAL product; END_ENTITY; ENTITY product_version; ident : identifier; name : label; description : OPTIONAL text; of_product : product; END_ENTITY; #1=product_category(“process vessel”,(#2),$) #2=product_category(“tank”,$,#3) #3=product(“fuel storage tank, 55 gals”) #4=product_version(“ver-001”,”Original Design”,$,#3)

21. Standard Data Access Interface - SDAI • Specifies a standard access mechanism to data- bases that can be specified in EXPRESS • Permits application system independence from data storage technologies • Has an object-oriented view of data, regardless of implementation • Implementations in a particular programming language require an interface language

22. Conformance Test Case (IGES or Part 21 files) Verdict Criteria Implementation Under test Validate IGES or Part 21 files Certification STEP Conformance Testing Conformance Test Case (hardcopy) Validate Hardcopy

23. STEP ARCHITECTUREEnd of Module 4