1. from research .… to market
Pieter Pauwels, Ghent University
Walter Terkaj, ITIA-CNR
Advances in ifcOWL standardisation:
technical overview
Sustainable Places 2015
SAVONA, Italy, 17th September 2015

2. http://www.bimforum.lv/communities/6/004/012/741/086//images/4611848847.jpg
openBIM
2

3. Industry Foundation Classes
(IFC) by buildingSMART
represents an open
specification for Building
Information Modeling (BIM)
data that is exchanged and
shared among the various
participants in a building
construction or facility
management project. The
specification consists of the
data schema, represented as
an EXPRESS schema
specification (ISO 10303-11),
and reference data
represented as Step files (ISO
10303-21) or XML files.
“Use of existing technical standards”
Industry Foundation Classes (IFC)
3

4. buildingSMART specifications
4

5. The Semantic Web Approach
Key advantages offered by Semantic Web technologies:
• Represent a formal semantic representation of data (both
T-box and A-box)
• Efficiently model and manage distributed data
• Enhance the interoperability of different applications
• Exploit generic tools that can infer from and reason about
an ontology, bringing out new derived knowledge about
the concepts and their relationships, in addition to those
initially asserted
• Process data outside the particular environment in which it
was created
5

6. Resource Description Framework (RDF)
A model for data interchange ; Information as a list
of statements in the form of triples composed of
subject-predicate-object. Any type of information
can be virtually expressed.
Flip side: The expressivity and flexibility imply the need
to revise some classical data management problems,
including efficient storage and query optimization
IFC as a graph (both Tbox as Abox)
(e.g. P. Pauwels, D. Van Deursen, R. Verstraeten,
J. De Roo, R. De Meyer, R. Van de Walle, J. Van
Campenhout. A semantic rule checking
environment for building performance checking.
Automation in Construction 20: 506-518, 2011)
6

7. Literature on EXPRESS to OWL (2005-2015)
Diverse suggestions in academic research to make IFC available as an OWL
ontology to allow the usage of semantic web technologies
 Schevers and Drogemuller, 2005
 Beetz et al., 2009
General purpose initiative to convert EXPRESS schemas and STEP file to OWL
ontology, not focused on IFC
 Krima et al., 2009 (OntoSTEP)
 Barbau et al., 2012 (OntoSTEP)
From 2012 onwards, increasing uptake in research and developments
=> many different ifcOWL structures floating around
Need for formalisation and standardisation
=> combine efforts and proceed in a more formalised, standard fashion
=> role of standardisation bodies: W3C, BuildingSMART
buildingSMART – Linked Data Working Group
• Technical Summit March 2015 (London)
• Next Technical Summit October 2015 (Singapore)
7
http://www.buildingsmart.org/standards/standards-organization/groups/linked-data-working-group/

8. converting EXPRESS schema to OWL
IFC
Schema
Simple data type
Defined data type
Aggregation data type
SET data type --------
LIST & ARRAY data type --------
Constructed data type
SELECT data type --------
ENUMERATION data type --------
Entity data type
Attributes --------
Derive attr
WHERE rules
Functions
Rules
ifcOWL
Ontology
owl:class + owl:DatatypeProperty restriction
owl:class
owl:class
-------- owl:ObjectProperty restriction on ifc:hasSet
-------- indirect subclass of ifc:List
owl:class
-------- owl:unionOf ( owl:classes )
-------- one of ( owl:NamedIndividuals )
owl:class
-------- object properties
-
-
-
-
8

9. EXPRESS to OWL and IFC to RDF conversion
9
Ifc2x_all_lf.exp
IFC2X2_ADD1.exp
IFC2X2_FINAL.exp
IFC2X2_PLATFORM.exp
IFC2X3_Final.exp
IFC2X3_TC1.exp
IFC4.exp
IFC4_ADD1.exp
not supported
not supported
not supported
not supported
IFC2X3_Final.owl / .ttl
IFC2X3_TC1.owl / .ttl
IFC4.owl / .ttl
IFC4_ADD1.owl / .ttl
IFC to RDF converter: work-in-progress, will be completed as soon as the
recommended ifcOWL is published
http://www.buildingsmart-tech.org/future/linked-data

10. Examples of IFC model as RDF graphs
10

11. Data
Model
Semantic
Repository
Data &
Knowledge
1
2
3
Digital
tools
DESSim
ActivityPlanning
CAD3D
…..
Legacy
System
Data
Base
Data
Base
…..
Ontology-based software interoperability
11
Credits to: Virtual Factory Framework (VFF), 7FP European project

12. (Ontology-based) Software Tools
12
Data
ModelSemantic
Repository
Data &
Knowledge
1
2
3 Software tools
ARENA®
PlantSimulation
GIOVE-VF
…..
Legacy
System
Data
Base
Data
Base
…..
• The connector “knows” both the
common Data Model and the
proprietary data model adopted by
the software tool.
• The software tool must offer a way to
access and modify (if needed) its
internal data structures, typically an
Application Programming Interface
(API).
New or existing, commercial or non-commercial software applications that support the various
required business processes. These tools, usually based on internal proprietary data
structures, will need the development of a dedicated Connector that takes of I/O translation
with respect to the common data model, thus enabling the platform integration.
Development steps
1. Mapping the classes and properties of the Data Model to the internal data model of the SW tool.
• If necessary, the Data Mode can be extended.
2. Software development of the Connector. Depending on the language required by the API of the digital
tool, different programming libraries can be exploited.
3. Population of the shared semantic repository with data and knowledge. Such population can be
accomplished by means of Graphical User Interface (GUI) tools, or by transferring data from existing
databases or legacy systems or by integrating other digital tools in VFF.

13. General structure of semantic integration
13
Software Tool - Connector
(arbitrary programing language)
Semantic Repository (RDF store)
Software Tool
MS04
MtC
Object mapping
Internal model of
the SW Tool
SW Tool
functionality
Output
feedback to
repository

14. Semantic Repository (RDF stores, Triple Stores)
Purpose-built database that provides a mechanism to handle RDF data
Types of RDF stores :
• DBMS-backed Stores
• Native Stores
• Hybrid Stores
Recent trend: Moved away from
relational approach to ones better
suited for exploiting the graph form
of RDF data
14

15. Examples of RDF stores
Which RDF store to use? It depends on what you need in terms of: data sets size; query
performance; quick, easy up and running; distributed, scalable.
15

16. Application scenario – Sustainable Factories
16
Credits to Italian research project «Sustainable Factory Semantic
Framawork» (SuFSeF) and partners ITC-CNR, ITIA-CNR, IMATI-CNR.
Project funded by Progetto Bandiera “La Fabbrica del Futuro”
(Flagship project “Factory of the Future”)
Foster the interoperability between software applications with a particular focus:
• Assess the factory sustainability considering all the aspects related: Resources, Wastes,
Process, Products, Energy consumption, Comfort and Sustainability of production
plants;
• Assess the factory sustainability with clear, objective, and standardized methodologies;
• Provide tools functional to factory management.
IFC/ifcOWL limitations:
• Insufficient details in both building and
resources information modelling to
handle sustainability aspects.
• The resource state concept is not
formalized. Energy consumption varies
dramatically based on the state in which
the resource is (e.g., idle, busy and
failed).
• The performance measure concept is not
defined in details.

17. 17
Data Model architecture: Ontology Modules
• StatisticsOntology: basic concepts about probability distributions and descriptive statistics.
• fsm: basic concepts to model a finite state machine.
• FsmExtension: extensions to fsm and integration with StatisticsOntology
• IFC_ADD1: ifcOWL automatically converted from IFC_ADD1.exp
• ifcOWL_rules: add class expressions to ifcOWL derived from WHERE rules in IFC_ADD1.exp
• ifcOWL_extension: integration of modules and general purpose extensions of ifcOWL
• FactoryDomain: specialization of ifcOWL with definitions related to products, processes, and systems
• SuFSeFFactory: specialization of ifcOWL and Factory concepts related to industrial building
sustainability.

18. Statistics Ontolology
18
- Lightweight ontology
- No commitment to upper ontologies
- Representation of basic probability distributions via semantic characterization of key
parameters
- Representation of descriptive statistics
- Focus on easy instantiation and integration with other ontologies
- Developed by W. Terkaj
Key differences vs STATO ontology
(http://stato-ontology.org/)

19. FSM Ontology
19
- Ontology representation of UML Statechart defined in OMG Unified Modeling Language (OMG UML),
Superstructure, Version 2.2
- Developed by Peter Dolog (http://people.cs.aau.dk/~dolog/fsm/)
Integration with Statistics Ontology and extensions:
- Addition of restrictions as class expressions
- Definition of the concept of State Frequency to be used to characterize an object history

20. ifcOWL
Industry Foundation Classes (IFC) by buildingSMART represents an open
specification for Building Information Modeling (BIM) data that is exchanged
and shared among the various participants in a building construction or
facility management project. The specification consists of the data schema,
represented as an EXPRESS schema specification (ISO 10303-11).
20
Automatic generation using a converter based on the pattern suggested by Pauwels&Terkaj:
- http://www.buildingsmart-tech.org/future/linked-data/linked-data
- https://www.w3.org/community/lbd/2014/12/12/ifcowl-ontology-file-added-for-ifc4_add1/

21. ifcOWL rules
Conversion of some EXPRESS WHERE rules into OWL Class Expressions to support direct instantiation
of ifcOWL and CWA/OWA validation/consistency check:
- Typing relationship between subclasses of IfcObject and IfcTypeObject
- Relationship between pre-defined property sets and subclasses of IfcObject/IfcTypeObject
21
IfcProductIfcTypeProduct
IfcElement
IfcBuildingElement
IfcElementType
IfcBuildingElementType
IfcWindowIfcWindowType
IfcTypeObject IfcObject
IsTypedBy only
IfcRelDefinesByType
RelatingType only RelatedObjects_of_IfcRelDefinesByType
only
Types only
Types only (RelatedObjects_of_IfcRelDefinesByType only IfcWindow)
IsTypedBy only (RelatingType only IfcWindowType)
SubClassOf
SubClassOf
SubClassOf
SubClassOf
SubClassOf
SubClassOf
SubClassOf
SubClassOf
Terkaj, Sojic (2015) Ontology-based representation of IFC EXPRESS rules: An enhancement of the ifcOWL ontology. Automation in
Construction, in press.

22. ifcOWL extension and Factory Domain
22
IfcProduct IfcProductState IfcProductHistoryFsmStateFrequency
hasStateMachine only hasStateFrequency onlyhasState only
IfcShapeRepresentation
IfcAxis2Placement
IfcProductDefinitionShape
hasObjectPlacement only
hasRepresentations only
hasStateRepresentationonly
IfcLocalPlacement
hasRepresentation only
hasRelativePlacement only
hasRelativePlacement onlyhasPlacementRelToonly
IfcRelAssignsToControlhasAssignments only hasRelatingControl only
IfcNormalizedRatio
Measure
hasStayRatio only
Extension and integration of ifcOWL, FSM and StatisticsOntology:
• ProductHistory is associated with changing states (state frequencies), placements
• ProductState is associated with representations
• StocastichQuantity to represents quantities that are related to probability distributions.
• Addition of restrictions to represents explicit/implicit constraints in IFC EXPRESS
Ontology module that adds further specialization for the industrial domain, in particular manufacturing:
• MachineTool, MachineToolType, Buffer, BufferType as specializations of IfcElement and
IfcElementType from ifcOWL
• MachineToolHistory as specialization of ProductHistory ifcOWL_extension
• MachineToolState as specialization of State from fsm
• Subclasses of IfcTask and IfcTaskType to represent manufacturing processes.

23. SuFSeF Factory
23
Ontologies that imports the previous general purpose modules and add further specialization for the
assessment of industrial buildings:
Focus on the data required to apply Protocollo ITACA, a methodology for the certification of
environmental sustainability of different building types (new or renovated), i.e.:
• Residential building
• Office building
• Commercial building
• Industrial building (http://www.itaca.org/documenti/protocollo_itaca/PROTOCOLLO%20ITACA%202011_I_070512.pdf)
• School building
ITACA is promoted by Italian regions and supported by iiSBE Italia and ITC-CNR.
For example, it’s needed to represent indicators such as the average mobile shields use (FSH indicator),
i.e. the weighted fraction of the time during which the solar shading is in use, and the shadowing factor
due to horizontal elements (HorizontalFin), i.e. the fraction of effective incident solar radiation due to
permanent horizontal elements shading the window (e.g. a balcony).
Indeed, these properties are used to define, for each building window, the total solar energy
transmittance (gt), that is then used to compute the ITACA indicator Effective average solar
transmittance of window/shading components.
http://www.itaca.org/valutazione_sostenibilita.asp

24. SOFTWARE TOOL for Layout Planning
GIOVE–VF
24
GIOVE-VF is a virtual reality collaborative environment to
support the factory layout design. Developed by ITIA-CNR onto
the C++ library GIOVE (Graphics and Interaction for
OpenGL-based Virtual Environments).
• Visualization of building, resources, etc.
• Placement of production resources
• Definition of main process plans
• Placement of human operators
• Visualization of simulation data
• Layout drawing import (DXF 2D)
• Multi user shared Virtual
Environment
• Checking and setting of distances

25. SOFTWARE TOOL for DES Simulation
Rockwell ARENA
25Corresponding author: Dr. Marcello Urgo, Politecnico di Milano (marcello.urgo@polimi.it)
ARENA module
MS04
MtC
Rockwell ARENA Simulation Environment
ARENA COM Interface
Automatic
Generation of
simulation model
Run
simulation
experiments
Collect and
analyze
simulation
results
ARENA-VF Connector
(based on C++ VfConnectorCpp Library by ITIA-CNR)
Repository containing VFDM-compliant Factory Projects
Ref: Dr. Marcello Urgo, Politecnico di Milano
(marcello.urgo@polimi.it)
The commercial simulation software tool ARENA has been integrated into VFF by
developing the Arena VF Connector that can be used to automatically generate simulation models
and then estimate main performance indicators such as throughput, resource utilization, average
system time, etc. (by Politecnico di Milano – Dipartimento di Meccanica)

26. SOFTWARE TOOL for Modeling Production Systems
OntoGui
26
ONTO-GUI is a tool providing a graphical user interface for managing the ontologies
that contain factory libraries or projects. The main window of the tool represents a
control panel that allows creating and exploring ontologies (by ITIA-CNR)
Location of
data repository
Available Ontology
Modules (projects
and libraries)
Characteristics of
the loaded
Ontology Module
Available
software tools

27. SOFTWARE TOOL for Modeling Production Systems
OWL Individual Manager tool
27
OWL Individual Manager allows exploring and generating OWL individuals that populate an
ontology. The interface of OWL Individual Manager is automatically reconfigured and generated
according to the content of the loaded Data Model, so that relations between individuals can be
easily defined (by ITIA-CNR).
Selectable OWL classes
Individuals belonging to
the selected OWL class
Explore the relations
involving the selected
individual. Feasible
relations are defined in
the Tbox.
Relations create a link
between the individual
and another individual
or a literal value.
Create and individual of the selected OWL
class in the specified RDF model

28. SOFTWARE TOOL for Modeling Production Systems
System Design and Performance Evaluation tools
28
System Design tool is an OntoGui module that
supports the design of a production system and
in particular the definition of part types, process
plans, machines and buffers. The process plans
can be decomposed into process step
characterized by precedence relations. Moreover,
the process steps can be assigned to the elements
of the production systems (by ITIA-CNR).
Performance Evaluation tool is an OntoGui
module that applies approximate analytical
methods to evaluate the performance of
production systems (by Politecnico di
Milano – Dipartimento di Meccanica)

29. 29
Industrial/Research Case – Demanufacturing Plant
Management, Monitoring and Reconfiguration
Area Carico scarico
1,20
4,40
2,80
2,00
In-Circuit
and
Boundary
Test
2,00
2,00
Functional+
AOI+PCB
remove
1,50
1,00
0,50
1,50
Stazione
Disassemblaggio
Meccatronico
3,00
4,00
Test
Funzionale
ECU
1,50
1,00
NastriLoad/
UnloadECU
PCB Warehouse
3,00
1,50
SMT Auto
Rework
1,50
2,00
Rework
PTH
1,50
1,00
Rework
Connectors
1,50
1,00
0,50
1,50
0,50
1,50
3,80
4,20
Triturazione e separazione materiale
0,50
1,50
0,50
1,50
De-Resinatura
2,00
1,40
50 Pallet
Unità Semi-automatica
Unità Automatica
Unità Manuale
Trasporto a Pallet
Trasporto a Nastro
Legenda
0,50
1,50
0,50
1,50
0,50
1,50
0,50
1,50
0,50
1,50
0,50
1,50
0,50
1,50
0,50
1,50
Nastro trasportatore PCB
0,50
1,50
0,50
1,50
0,50
1,50
0,50
1,50
Accessomanutenzione
Components
warehouse
1,50
1,00
OperatingUnit
X
1,50
1,00
OperatingUnit
Y
1,50
1,00
OperatingUnit
Z
1,50
1,00
TrasportocomponentiAGVaereo
Cella Futura
1
2
3
4
5
6
7
8
9
10
Reusable
boards
End-Of-Life
Reusable
Components
Reusable
Materials
De-Manufacturing: the
processes which comprehend
the disassembly, re-
manufacturing, recycle and re-
use of products and
components.
In 2011 ITIA-CNR started the
conception of the De-
Manufacturing factory by
realizing a demonstration pilot
plant for the integrated EOL
management of PCBs.
Consumers
IT &
Telecom
IPC, PLC,
Drivers…
White
Goods…

30. 30
Cell 1
Robotic disassembly
Cell 2
testing, repair
disassembly.
Transport System
PCB conveyor
Cell 3
shredding
separation
Industrial/Research Case – Demanufacturing Plant
Management, Monitoring and Reconfiguration

31. 31
Industrial/Research Case – Demanufacturing Plant
Management, Monitoring and Reconfiguration

32. Energy consumption prediction via DES
Cataldo, R. Scattolini, T. Tolio (2015) An energy consumption evaluation
methodology for a manufacturing plant. CIRP Journal of Manufacturing Science and
Technology, in press.
• A methodology (CSM) for transport energy behaviour prediction.
• CSM can be easily applied to other manufacturing systems.
• De-manufacturing transport line Discrete Event Simulator formulation.
• Validation of CSM through simulations and real plant experiments.
32
Pallet transport line power simulation and measurement results.

33. from research .… to market
Pieter Pauwels, Ghent University
Walter Terkaj, ITIA-CNR
Advances in ifcOWL standardisation:
technical overview
Sustainable Places 2015
SAVONA, Italy, 17th September 2015