=Paper=
{{Paper
|id=Vol-2900/WS8Paper4
|storemode=property
|title=Pathways to CP(P)S Modelling & Architecting
|pdfUrl=https://ceur-ws.org/Vol-2900/WS8Paper4.pdf
|volume=Vol-2900
|authors=Georg Weichhart,Hervé Panetto,Wided Guédria,Gash Bhullar,Néjib Moalla
|dblpUrl=https://dblp.org/rec/conf/iesa/WeichhartPGBM20
}}
==Pathways to CP(P)S Modelling & Architecting==
https://ceur-ws.org/Vol-2900/WS8Paper4.pdf
Pathways to CP(P)S Modelling & Architecting
Georg Weichharta, Hervé Panettob, Wided Guérdiac, Gash Bhullard and Néjib Moallae
a
PROFACTOR, Im Stadtgut A2, 4407 Steyr-Gleink, Austria
b
University of Lorraine, CNRS, CRAN, BP 70239 - F54506 Vandoeuvre-les-Nancy Cedex, France
c
Luxembourg Institute of Science and Technology (LIST), 5 Avenue des Hauts Fourneaux, L-4362 Esch/Alzette,
Luxembourg
d
Control 2K Limited, Waterton Technology Centre, Bridgend, South Wales, CF31 3WT, United Kingdom
e
University of Lyon II, DISP Laboratory, 21 Avenue Jean Capelle O, 69100 Villeurbanne, France
Abstract
Enterprise Interoperability is getting more important in a world where enterprises are
digitalizing everything. Interoperability is an extension to integration by aiming at loose
coupling of systems and see integration as a continuous process. In manufacturing the trend in
digitalization is aiming at Cyber-Physical Production Systems (CPPS). In this short paper, we
are looking for pathways representing different stages to Interoperable Cyber-Physical
(Production) Systems.
Keywords 1
Cyber-Physical Systems, Enterprise Modelling, Enterprise Architecture, Enterprise
Interoperability, Enterprise Integration
1. Introduction
Enterprise Systems today are connected information systems. The term information system is used
in a very general sense, which includes humans and artificial agents (including software), providing
and consuming information. Many sensors across the enterprise are generating data that is used by
human decision makers through decision support applications. Decisions trigger information and
control flows in the other direction and actuators translate that information into physical action.
Smart Sensors, Virtual Sensors, Industrial Internet-of-Things (IIoT) are technology trends with
respect to sensing. Business Analytics, Business Intelligence, together with cloud computing, edge
computing technologies provide the infrastructure and tools for supporting decision making. Cloud
Robotics and Additive Manufacturing are two examples where information systems control physical
aspects (in the manufacturing enterprise).
Taking an information systems perspective we can describe the data flows between information
processing systems (including human and artificial agents). This point of view excludes any physical
aspect.
A Cyber-Physical Systems (CPS) point of view is needed. A CPS is a system that integrates physical,
computational sub-systems that are connected through a network [1]. Here, a CPS is not a traditional
embedded system or real-time system [2]. CPS integrate cyber and physical parts in every sub-system.
The network is an integral part of the CPS. These two properties are the basis to have a system that is
dynamically reconfigurable. High degrees of automation allow self-organization and adaptation to
reach higher performance [2]. To handle complexity and scalability of large networked CPS a systems-
of-systems approach is taken. In such systems, the cyber and the physical systems are physically
distributed but still must be interoperable in one larger system [3].
Proceedings of the Workshops of I-ESA 2020, 17-11-2020, Tarbes, France
EMAIL: georg.weichhart@profactor.at (Georg Weichhart); herve.panetto@univ-lorraine.fr (Hervé Panetto); wided.guedria@list.lu (Wided
Guédria); gbhullar@control2k.co.uk (Gash Bhullar); nejib.moalla@univ-lyon2.fr (Nejib Moalla);
ORCID: 0000-0002-1405-5825 (Georg Weichhart); 0000-0002-5537-2261 (Hervé Panetto); 0000-0003-4806-0320 (Nejib Moalla)
©️ 2020 Copyright for this paper by its authors.
Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
CEUR Workshop Proceedings (CEUR-WS.org)
A Cyber-Physical Production Systems (CPPS) takes this paradigm of connected and distributed
systems and puts it into a manufacturing context [4]. It allows to discuss distributed, large scale, and
complex CPS from a supply chain and shop floor point of view [5].
Among other topics, interoperability in such distributed and dynamic systems is a key research
challenge that needs to be addressed from a technological, semantic and organizational perspective [5],
[6], [7].
2. Pathways
In order to map different possible routes for Enterprises (and Researchers) to a vision for
Interoperable Cyber-Physical (Production) Systems, we use a method called pathways. This method
builds on work by EFFRA (European Factories of the Future Research Association) Public Private
Partnership organization. This method maps different levels towards a vision.
The following image gives an example. It was created by EFFRA, and shows the Autonomous Smart
Factory Pathway. Level 1 is defined as a situation where individual office software application used. In
this phase, data acquisition is manual and application specific. Level 2 is a situation where the data is
automatically collected and used for planning. However, the data is used in isolation. Level 3 is about
connected software. In level 4 situation optimization of plans happens before production runs (offline
optimization). Level 5 is online optimization reacting to changes immediately.
On a general level, the pathways method allows different levels at the same time in subsystems. It
does not define a strict one-way route. It has also to be mentioned, that while level 5 is the most
advanced with respect to the given vision, it strongly depends on the situation if reaching that level does
make sense. Complexity and associated costs will increase from level to level.
Figure 1: EFFRA Autonomous Smart Factory Pathways (www.effra.eu)
As can be seen the pathways follow a simple schema. We will use that schema to discuss
interoperability of cyber-physical (production) systems.
3. Interoperability of Cyber-Physical Systems
For the analysis of pathways to CPS modelling and architecting, we first take a look at three levels
of analysis taken from enterprise interoperability (EI) [5]. EI uses a systemic perspective [8]. It
addresses the enterprise as a system-of-systems [9]. Organizations are physical systems and EI
discusses interoperability between information systems, data models and physical systems.
The used, simplified framework, discusses enterprise interoperability on three levels. The
technology level includes data structures, programming interfaces, technological standards that allow
to have multiple technical systems interact. The semantic level, discusses tools and approaches that
allow systems and humans to understand the meaning of data/information. The third level is the
organizational level, where interoperability issues arise if different organizations have, for example,
different processes or rules with respect to information access (security, privacy, etc.).
From level I to level IV the pathway moves from an isolated system over simple exchange of
data/information/knowledge flows to a level where high dynamics and self-organization among human
and artificial agents is possible. The different levels give the different stages a name but are not
normative. Level V supports self-organization of systems, which are connected and exchange
information with an agreed semantics of the exchange.
Table 1
Pathways for Interoperability of Cyber-Physical Systems
Aspect Level I Level II Level III Level IV Level V
Technology Closed Systems System specific Open APIs Standards Infra-structure for Self-
API2s Organization of
systems-of-systems
Semantics Data Silos Semantic Onto-logical Open Data Advanced
Description Data Sets Reasoning and Planning
Structures of Agents
Organizational Isolated Group Hierarchies Process Agile Teams Enterprise as Complex
of People Management Adaptive System
4. Cyber-Physical (Production) Systems Modelling & Architecting
Based on the above point of view, we propose these pathways for Modelling and Architecting of
Cyber-Physical (Production) Systems. It addresses the different needs of systems that range from
isolated systems to dynamic systems-of-systems (SoS) capable of self-organization.
Table 2
Pathways for Cyber-Physical (Production) Systems Modelling & Architecting
Aspect Level I Level II Level III Level IV Level V
System Isolated Adaptive Connected System-of- Cyber- Physical
System System Systems system SoS
Model Static Model Dynamic Heterogeneous Distributed Agent-based
of a system Model / models Systems modelling and
Simulation modelling negotiation
Interoperability Compatible Tight Standard Loose Federated
Environment Integration Interfaces Integration Interoperability
2
Application Programming Interface
The systems aspect describes the relationship of the system to other systems. As such it includes an
abstract view on the complexity. The model aspect takes a look on the model in general with respect to
dynamics. Interoperability is seen on a continuum. Compatible is a level, where multiple systems are
not working together, but simply do not disturb each other. Tight integration is often the result of one-
off modelling and implementation efforts, where the systems are coupled in a way that makes them
strongly dependent on each other. Standard interfaces provide an initial way to a loose coupling were
individual systems can be exchanged with other systems. Loose Integration refers to a situation where
exchange of systems is the norm not the exception. Federation means that interoperability and interfaces
are communicated / negotiated at runtime rather at design time. Level IV and V need a supportive
environment and general standardized system services that allow to maintain a loose coupling over
time.
5. Conclusions and perspectives
We have used the pathways method to sketch different levels of interoperability in Cyber-Physical
Systems. The sketched pathways are used as initial input in order to start a scientific discussion on how
to enable loose integration (aka. Interoperability) of such systems.
We hope the discussion will bring forward technologies and methods that make cyber-systems,
physical-systems and cyber-physical systems interoperable. Organizational aspects and production
technologies and physical production process need to be included not only information systems and
software systems perspectives.
6. Acknowledgements
The research described in this paper has been partially funded by the European Union and the state
of Upper Austria within the strategic economic and research program “Innovative Upper Austria 2020"
and the projects "Smart Factory Lab" and "DigiManu". It also has been supported by Pro2Future (FFG
under contract No. 854184). Pro2Future is funded within the Austrian COMET Program - Competence
Centers for Excellent Technologies - under the auspices of the Federal Ministry for Climate Action,
Environment, Energy, Mobility, Innovation and Technology (BMK) and the Federal Ministry for
Digital and Economic Affairs (BMDW) and of the Provinces of Upper Austria and Styria. COMET is
managed by the Austrian Research Promotion Agency FFG.
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[3] W. Wolf, Cyber-physical Systems, Computer, March (2009) 88-89
[4] A. Zeid, S. Sundaram, M. Moghaddam, S. Kamarthi, T. Marion, Interoperability in Smart
Manufacturing: Research Challenges, Machines, 7, 2 (2019) 1-17
[5] H. Panetto, B. Iung, D. Ivanov, G. Weichhart, X. Wang, Challenges for the Cyber-Physical
Manufacturing Enterprises of the Future, Annual Reviews in Control, 47 (2019) 200-213
[6] A. Napoleone, M. Macchi, A. Pozzetti, A review on the characteristics of cyber-physical systems
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(2017) 4–19. doi:10.20965/ijat.2017.p0004
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