1. International Conference on Concurrent Enterprising TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 A Generic Approach to the Mapping Problems in Cooperative Design U. Wagner, Dr. P. Katranuschkov, Prof. Dr. R. J. Scherer TU Dresden, Germany Presentation at ICE 2001 Bremen, Germany, June 2001

2. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 Overview  The Problem Domain  The Model Mapping Approach  The Mapping System Mapping languageMapping language Mapping language parserMapping language parser Implementation of the mapping engineImplementation of the mapping engine ExampleExample  Conclusion

3. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 The Problem Domain  There are several differences b/n Building Construction and other industries : Lower profits, lower IT investment Lack of large key organisations as technology drivers Complex supply and communication chains  Therefore: Concurrent engineering & cooperative design have to deal with complex model transformations in a distributed non homogeneous model world  Such transformations may be needed e.g. for: Data exchange between major CAD-Applications Generation of views (presentation, documentation, pre- and post-processing) Coordinated change management Extracting of management information for control and monitoring etc.

4. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 The Problem Domain Architect Structural Engineer HVAC Engineer Controls Engineer Constr. Manager Facilities Manager Building Owner Civil Engineer SHARED PROJECT MODEL Architect Structural Engineer HVAC Engineer Controls Engineer Constr. Manager Facilities Manager Building Owner Civil Engineer Not fully sufficient The IAI Vision of Interoperability Not fully sufficient are also all known database integration approaches

5. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 The Model Mapping ApproachBackground: Underlying product modelling framework (IFC) Non fully harmonised domain / application models Distributed, a-priori non coordinated data Distributed C/S architecture with underlying shared data repositoryNote: Mapping is an alternative to full harmonisation/integration methods But: Model mapping supports and does not contradict to integration! Principal approach:  Consolidation of the project data only at discrete co-ordination points

6. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 The Model Mapping Approach T1T1 T0T0 Struct. Model S 0 map (A 0) MAPPING S 1 map (A 1) Arch. Model A 0 Matching Struct. Model S 1 merged Merging models are diff. Struct. Model S 1 local Arch. Model A 1 design changes models are semantically equivalent MAPPING coordination point T0T0 T1T1 TNTN process phase

7. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 The Mapping System  A mapping language - CSML  A generic parser - MaLaPaG  Explicit public operations enabling distributed C/S realisations  A set of implementation methods comprising the interoperability engine (server-side object-oriented methods based on set theory)

8. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 Characteristics of CSML  Declarative language  Mapping of two (full or partial) models  Context-free grammar  Recursively specified  the rules are directly realizable  Predefined mapping patterns for typical problems on class, instance and attribute level  Better suited to real-time distributed systems than EXPRESS-X  Less suited for model evolution and model migration  Still under development …

9. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 The Generic Parser (MaLaPaG)  Basically, instead of developing parsing rules for all language constructs, the language itself is used as input in the parser  More difficult to realize than a static parser  But: applicable for a class of similar languages  Easy to modify by changes in the language specification  Static vs. Generic Parser: Static Parser: statically integrated rulesstatically integrated rules designed for a specific languagedesigned for a specific language low development effortlow development effort high maintenance efforthigh maintenance effort Generic Parser: rules are externally stored suitable for different languages high development effort low maintenance effort

10. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 Hashing the Rule Map

11. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 Implementation of the Mapping Engine  Input data sets: The source and target schemas in EXPRESS The source model data The CSML specification providing the mapping rules for the translation of the source model data into the target model data  Processing: Parsing of the EXPRESS schemas Parsing of the CSML specification Recursive generation of the source & target data sets Compressing the target data by eliminating redundancies  Output data set: The target model data e.g. in the form of a STEP exchange file or as a XML document (see ifcXML)

12. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 Example Source Schema: Source Schema: Target Schema: SCHEMA shared_model; ENTITY circle; centre: point; centre: point; radius: REAL; radius: REAL; END_ENTITY; END_ENTITY; ENTITY Point; ENTITY Point; x, y, z: REAL; x, y, z: REAL; END_ENTITY; END_ENTITY; END_SCHEMA; END_SCHEMA; SCHEMA local_model; ENTITY circ; centre : point; centre : point; diameter : REAL; diameter : REAL;END_ENTITY; ENTITY Point; x_coord : REAL; x_coord : REAL; y_coord : REAL; y_coord : REAL; z_coord : REAL; END_ENTITY; z_coord : REAL; END_ENTITY;END_SCHEMA; (MAP local_model FROM shared_model CLASSES CLASSES ( MAP CLASS circ FROM circle ( MAP CLASS circ FROM circle ATTRIBUTES ATTRIBUTES (SAME centre) (SAME centre) (MAKE diameter FROM radius APPLY (MAKE diameter FROM radius APPLY (LAMBDA (X) (* X 2.0)))) (LAMBDA (X) (* X 2.0)))) DEPENDENT-CLASSES DEPENDENT-CLASSES (MAP CLASS point FROM point (MAP CLASS point FROM point ATTRIBUTES ATTRIBUTES (SAME x_coord y_coord z_coord AS x y z) (SAME x_coord y_coord z_coord AS x y z) ) ) Mapping Specification:

13. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 Parser Tree for the Example MAP : local_model FROM : shared_model CLASSES MAKE : diameter FROM : radius APPLY : (LAMBDA (X) (* X 2.0)) MAP CLASS: circ FROM : circle MAP CLASS: point FROM : point SAME: centre SAME : x_coord y_coord z_coord AS x y z ATTRIBUTES DEPENDENT- CLASSES ATTRIBUTES Schema mapping Class mapping Leaf nodes Attr. mappings

14. TU Dresden, Lst. für Computeranwendung im Bauwesen C Wagner, Katranuschkov, Scherer 27-June-2001 Conclusions  The modular mapping system provides greatest freedom for independent, parallel design work  The integration of a generic parser provides a high level of flexibility enabling easy re-adjustment of the environment  As a whole, the presented approach fulfils major interoperability requirements of a concurrent engineering environment in building design