Catherine Biscarat

Bernard Boutherin

Sabine Crépé-Renaudin

Christine Gondrand

Rachid Guernane

Fabian Lambert

Demande de passage à un noeud de type Tier 2 de WLCG pour le noeud de grille du Laboratoire de Physique Subatomique et de Cosmologie de Grenoble

Deux équipes du LPSC ont participé à la conception, la construction et aujourd'hui à l'exploitation des expériences ATLAS et ALICE du LHC. Afin de permettre aux physiciens d'aborder les phases de prise de données et d'analyse de ces expériences dans les meilleures conditions et aussi de participer au traitement des données du LHC, le LPSC s'est doté d'un noeud de grille de calcul de type Tier 3 1 . Ce noeud a été mis en production en janvier 2008. Depuis, le site a prouvé ses capacités à participer au calcul LHC, il s'est agrandi et ouvert à d'autres disciplines.

Après une année de fonctionnement du LHC, considérant l'évolution des stratégies de traitement des données de ses expériences, le bon fonctionnement du site, l'implication du personnel du laboratoire et la volonté des groupes de physiques d'exploiter au mieux les moyens de calcul LHC du laboratoire et de s'impliquer plus encore dans le calcul LHC, nous demandons le passage du noeud de grille du LPSC au niveau Tier 2 de WLCG 2 .

Le noeud de grille du LPSC

1.1. Bref historique Après une petite participation à « datagrid » en 2001, c'est en 2006 que le LPSC a décidé de créer un noeud de grille LCG suite à la demande des physiciens du groupe ATLAS. Le laboratoire a investi dans l'aménagement d'une salle informatique avec un système de refroidissement original basé sur la technique du « free cooling » 3 et dans toute l'infrastructure nécessaire à l'accueil d'un noeud de grille. Après une phase de tests en 2007 et l'achat des premiers matériels soutenus par le LPSC, les groupes de physique LHC du laboratoire et l'Institut des Grilles, le site est mis en production en janvier 2008.

Description du noeud de grille

Actuellement, le Tier 3 du LPSC se trouve dans la salle informatique du laboratoire, qui permet l'hébergement de 8 baies 42 U avec une puissance électrique disponible de 120 kW. La salle dispose d'un onduleur (30 kVA) pour les services critiques et d'un système de refroidissement par « free cooling » particulièrement fiable, d'une puissance de 100 kW.

Le Tier 3 occupe aujourd'hui 5 des 8 baies disponibles dans la salle informatique du LPSC. Sa capacité de calcul est constituée de 80 serveurs, correspondant à 640 coeurs d'une puissance totale de 5 405 HEP-SPEC 06 4 . Quant au stockage, 19 serveurs offrent une capacité de 672 To brut qui

L'ensemble de la grille est surveillé via le serveur NAGIOS du LPSC.

Le réseau

Le coeur du réseau local est basé sur 2 switchs CISCO NEXUS 5010 dotés de 40 ports à 10 Gbits/s. Le LPSC étant situé sur le polygone scientifique de Grenoble, la connexion à RENATER dont le point de présence est sur le campus de Saint-Martin-d'Hères se fait via le réseau métropolitain Metronet. Le point d'accès de ce dernier pour le CNRS est géré par le laboratoire Louis Néel. Le débit maximum actuel est de 1 Gbits/s. Une évolution à 10 Gbits/s est en cours de négociation ; elle s'appuiera sur la mise en place par RENATER d'un nouveau point de présence à Grenoble sur le site du Polygone scientifique, ou si ce projet est abandonné, via une évolution des équipements de l'Institut Néel. Le point de présence RENATER est ensuite relié par fibre noire à 10 Gbits/s à Lyon, Genève et Cadarache.

Le personnel

Les activités du LPSC étant structurées sous forme de projet, la plateforme technique du Tier 3 du LPSC possède un responsable scientifique et un responsable technique. Parmi les membres du service informatique qui permettent le bon fonctionnement du site, on notera que deux ingénieurs travaillent quotidiennement sur le projet pour l'équivalent d'un temps plein. D'autre part, un ingénieur de recherche vient d'être recruté pour renforcer cette équipe. L'activité principale du site étant le calcul LHC, un physicien pour chacun des groupes LHC du laboratoire fait le lien entre le site et les besoins des groupes ALICE et ATLAS. On notera d'autre part, qu'une collaboration s'est engagée autour des grilles de calcul et de l'informatique verte entre le service informatique du LPSC et le groupement de laboratoire pour le calcul intensif CIMENT 8 . CIMENT vise au développement de projets de calcul de type méso-centre au sein des universités grenobloises. D'autre part, Ciment a déployé une grille de calcul exploitée via le logiciel CIGRI qui permet de fédérer plusieurs clusters. L'objectif principal de la collaboration entre le LPSC et CIMENT est de donner accès aux utilisateurs de CIMENT à la grille EGEE/EGI et réciproquement. Au début de l'année 2010, avec l'arrivée de nombreux sites Tier 3 avec des services de grille minimaux, la collaboration ATLAS a clairement différentié les activités des Tier 3 et des Tier 2 en particulier en matière de distribution des données. Les données n'étant plus automatiquement importées, l'activité d'analyse s'est donc restreinte aux utilisateurs locaux qui importent les données des groupes de physique auxquels ils appartiennent ou leurs propres données d'analyse ainsi qu'aux utilisateurs extérieurs intéressés par ces données particulières. De plus, il n'est pas possible pour un Tier 3 de recevoir automatiquement les données des groupes de physique traitées via la production centrale, la copie de ces données ne peut donc être faite que manuellement. Pendant cette période, l'activité de production Monte Carlo a pu être poursuivie. Par contre, la collaboration ATLAS a clairement séparé les tests et services des Tier 3 de ceux des Tier 2 quels que soient leur taille et leurs performances.

La gestion

Cette évolution de l'utilisation des Tier 3 par la collaboration ATLAS est l'une des raisons qui ont mené à cette demande de passage à un site de type Tier 2.

Depuis la mise en fonctionnement du site, son utilisation par ATLAS a été constante (voir Figure 2). La répartition des tâches ATLAS au LPSC depuis janvier 2010 est décrite sur la Figure 3. L'augmentation du nombre de tâches d'analyse depuis l'automne 2010 est particulièrement visible et correspond au traitement et à l'analyse de la première période de prise de données du LHC. L'activité du site du LPSC représente pour le premier trimestre 2011 environ 3% de l'activité de l'ensemble des sites du nuage français tant du point de vue de la production que de l'analyse. Rappelons que le nuage français regroupe l'ensemble des sites français et des sites roumains qui participent à ATLAS ainsi que le site chinois de Beijing et le site japonais de Tokyo.

On notera aussi que l'efficacité du site est très bonne : au dessus de 90% pour la production. Elle est tout à fait comparable aux autres Tier 2 du nuage français comme le montre la Figure 4.

Performances

Le site du LPSC étant un Tier 3, il n'avait jusque-là pas à s'assurer que le minimum de performances exigées pour les sites Tier 2 était atteint. Cependant, afin d'assurer un service de qualité à ses utilisateurs, le personnel du LPSC s'est attaché à maintenir le site à un très bon niveau de disponibilité et de fiabilité.

Pour illustrer les performances du site depuis sa création, les valeurs de ces deux variables telles que définies et enregistrées par WLCG sont montrées en fonction du temps sur la Figure 6.

En moyenne sur l'année 2010, la disponibilité du site est de plus de 91 %, valeur supérieure au 90 % demandé pour les Tier 2. La fiabilité est proche de 92 % alors que la valeur exigée pour un Tier 2 est de 95% : un effort sera donc nécessaire dans ce domaine. On notera cependant que pour les premiers mois de 2011, ce seuil est largement atteint.

Motivations de la demande de passage au niveau Tier 2

Considérant le démarrage du LHC, l'évolution du modèle de calcul des expériences, les besoins en calcul des physiciens, le bon fonctionnement du site et l'implication du personnel technique et scientifique, nous désirons passer du statut de Tier 3 à Tier 2. Les activités des groupes de physique LHC du LPSC et les motivations de cette demande sont développées dans les paragraphes qui suivent.

La physique du LHC au LPSC

Le groupe ATLAS du LPSC a été créé en 1991. Il a entre autre conçu, participé à la construction, à l'installation et à la mise en fonctionnement du pré-échantillonneur du calorimètre électromagnétique de l'expérience ainsi que du système de cryogénie de ce détecteur. D'autre part, depuis de nombreuses années, des ingénieurs du service informatique sont responsables de deux applications essentielles qui font partie de l'infrastructure logicielle de l'expérience : l'application AMI (ATLAS Metadata Interface) qui est un des points d'entrée pour les physiciens afin de découvrir les données disponibles pour l'analyse et l'application « Tag Collector » qui permet la gestion des versions du logiciel d'ATLAS. Enfin, en parallèle des activités de préparation à l'analyse des données ont été menées.

Le groupe est aujourd'hui composé de 14 physiciens, 8 doctorants et 3 ingénieurs. Depuis le démarrage du LHC ses activités se sont concentrées sur la mise en route, le suivi du fonctionnement et l'étude des performances du calorimètre électromagnétique, le développement des applications logicielles décrites ci-dessus, le support au fonctionnement de la grille de calcul LHC sur le « nuage » français et au Tier 3 du LPSC et bien entendu la préparation et l'analyse des données. Les thématiques actuelles du groupe sont la reconstruction et l'étalonnage des « jets » de particules hadronique, l'étiquetage des quarks b et, en ce qui concerne les thématiques de physique, la physique du top et la recherche de nouvelles particules (bosons neutres ou particules supersymétriques).

Créé en 2006, le groupe de physique ALICE du LPSC est maintenant composé de 7 physiciens et 2 doctorants. Son axe de recherche porte sur la mesure des jets de particules et des photons de

Organisation du site en tant que Tier 2 et plan de déploiement des ressources

Le site ayant fonctionné jusqu'à présent quasiment comme un Tier 2, son organisation n'a pas besoin d'évoluer de façon importante s'il accède à ce niveau. L'arrivée d'un nouvel ingénieur de recherche dont l'activité est centrée sur la grille de calcul permettra cependant d'augmenter l'implication technique du LPSC dans ce domaine.

Conclusion

Le Tier 3 du LPSC a été mis en production en janvier 2008. Depuis sa création, ses capacités de calcul et de stockage ont régulièrement augmenté pour atteindre 5 405 HEP-SPEC 06 et 454 To net de stockage. Ceci lui permet d'assurer aujourd'hui environ 3 % des tâches d'analyse et de production du nuage français d'ATLAS et 7 % pour ALICE. Le site a démontré sa capacité à assurer un service de qualité aux expériences LHC auxquelles il participe en termes de disponibilité, de fiabilité et d'efficacité. D'autre part, avec la mise en fonctionnement du LHC, la croissance des groupes de physique ATLAS et ALICE au LPSC et leur implication de plus en plus grande dans l'analyse des données du LHC, les besoins des physiciens du LPSC en terme de grille de calcul sont devenus importants.

Considérant donc, les performances du site, l'implication de son personnel technique et scientifique, l'évolution des stratégies de traitement des données du LHC et les besoins des groupes ATLAS et ALICE du LPSC ainsi que leur volonté de poursuivre leur implication dans le calcul LHC, nous demandons le passage du site du LPSC au niveau Tier 2 pour les collaborations ATLAS et ALICE.

correspond à 454

 454 To net (utilisable sous le « Disk Pool Manager » DPM 5 ). Les évolutions de la puissance de calcul et de stockage depuis 2008 sont représentées sur la Figure 1. Les achats qui seront effectués courant 2011 ne sont pas pris en compte sur cette figure.

Figure 1 :

 1 Figure 1 : Évolution de la capacité de calcul (en haut) et de stockage (en bas) du noeud de grille du LPSC (* en bleu foncé la capacité net utile telle que vue par DPM).

  Les évolutions du site sont discutées dans le Comité Technique Informatique du laboratoire dirigé par un représentant du Conseil d'Unité et constitué par le personnel du service informatique et des représentants des activités scientifiques et techniques du laboratoire utilisant les ressources informatiques. 1.6. Les activités du site Le site du LPSC est principalement utilisé pour le calcul LHC. Les premières « Virtual Organisations » (VO) à y être installées ont donc été, outre les VO Ops et dteam permettant de tester le bon fonctionnement du site, les VO ATLAS et ALICE. Depuis, le site s'est ouvert à d'autres disciplines, qu'elles soient régionales (VO Rhônes-Alpes, EUMED pour les pays méditerranéens), ou qu'elles correspondent à des besoins d'équipes du LPSC (VO LPSC ouverte à tous les membres du LPSC, VO Calice pour le groupe participant à ILC, VO MURE dédiée à la simulation de réacteur nucléaire, VO Biomed pour l'imagerie médicale).

L

  'évolution de l'utilisation du site en termes de CPU depuis sa création est montrée sur la Figure 2. Comme il a été déjà mentionné, la figure indique clairement que le site est majoritairement utilisé par les expériences LHC, ATLAS et ALICE.

Figure 2 :

 2 Figure 2 : Évolution du temps de calcul normalisé utilisé par les différentes VO supportés par le LPSC depuis la mise en production du site

Figure 3 :

 3 Figure 3 : Répartition du nombre et du type de tâches (par semaine) traitées par le site du LPSC depuis janvier 2010 pour l'expérience ATLAS.

Figure 4 :

 4 Figure 4 : Efficacité des tâches de production par site sur le nuage français en 2010. NB la valeur pour IN2P3-CC-T2 est erronée, le site n'ayant pas été correctement monitoré sur l'ensemble de l'année 2010.

Figure 5 :

 5 Figure 5 : Profil d'utilisation des ressources CPU (nombre de tâches courantes) pour l'année 2010 (points bleus).

Figure 6 :Figure 5 :

 65 Figure 6 : Disponibilité (en bleu clair) et fiabilité (en bleu foncé), d'après WLCG, du site du LPSC en fonction du temps.

  En ce qui concerne les ressources, une proposition d'évolution jusqu'en 2012 est présentée dans le Tableau 1. Les ressources associées à la partie Tier 2 en 2011 ont été calculées à partir des ressources disponibles début 2011, de la clé de répartition entre ATLAS et ALICE et des besoins du groupe ATLAS local pour l'analyse. La clé de répartition utilisée est de 75 % des ressources financières pour ATLAS et de 25 % pour ALICE, ce qui correspond à la fois à la clé de répartition de LCG-France et à la répartition du nombre de physiciens dans les groupes ATLAS et ALICE du laboratoire. En ce qui concerne 2012, l'évolution a été calculée en prenant en compte la demande d'évolution des expériences en stockage et CPU en s'assurant en particulier de respecter au mieux le rapport CPU/disque demandée par les expériences. L'augmentation des ressources est basée sur une hypothèse de financement du site similaire à celle de 2011. On notera en particulier que le Conseil d'Unité du LPSC a approuvé la demande de passage Tier 2 de son site 10 et qu'afin de soutenir le passage au niveau Tier 2, le LPSC continuera d'investir dans son développement dans la mesure de ses capacités financières. Par ailleurs, en cette année financièrement difficile aucun soutien de l'IN2P3, de LCG ou de l'Institut des Grilles n'a été obtenu à ce jour pour soutenir le passage au niveau Tier 2 de notre site. LCG-France apporte cette année le soutien minimal prévu aux sites Tier 3 soit 10 k . Le plan de déploiement des ressources présenté ici sera ajusté pour 2012 en fonction des financements réellement obtenus. Tableau 1 :Prévision de déploiement des ressources du LPSC.

dans la nomenclature de la collaboration WLCG

http://lcg.web.cern.ch/LCG/

http://lpsc.in2p3.fr/informatique/ecoclim.html

https://twiki.cern.ch/twiki/bin/view/FIOgroup/TsiBenchHEPSPEC

https://svnweb.cern.ch/trac/lcgdm/wiki/Dpm

https://twiki.cern.ch/twiki/bin/view/EGEE/BDII

http://quattor.sourceforge.net

Technical Design Report of Computing CERN-LHCC-2005-018

2.2. Les besoins des groupes LHCEn ce qui concerne ATLAS, le groupe désire continuer à participer au calcul LHC tant du point de vue de la production que de l'analyse. L'actuelle politique d'ATLAS qui consiste à réserver la distribution automatique des données aux seuls Tier 2 a pénalisé le site et ses utilisateurs en ce qui concerne l'analyse (voir paragraphe 1.6.1). D'autre part, le LPSC est maintenant le seul Tier 3 français participant à ATLAS, or son implication ainsi que ses performances sont similaires à celles des autres Tier 2, il est donc naturel que le site accède au même niveau que ses partenaires français et offre à ses utilisateurs le même niveau de service. Le nombre de physiciens du LPSC participant à l'analyse des données d'ATLAS a nettement augmenté ces dernières années et leurs besoins en termes de calcul ont augmenté en proportion, il est donc important que le site du LPSC leur propose des ressources en adéquation avec leurs besoins.Concernant ALICE, le passage Tier 2 du site du LPSC garantit, outre une qualité de services et la pérennité des données, la possibilité de prétendre à la réplication ciblée de données d'analyse nécessaire pour une calibration rapide du calorimètre électromagnétique.

grande impulsion transverse (de quelques centaines de GeV) en collisions d'ions lourds ultrarelativistes afin de caractériser les propriétés du plasma de quarks et de gluons. Cette mesure requiert la mise en oeuvre d'un calorimètre de grande acceptance pour la mesure de l'énergie des particules au sein des jets sur une large dynamique en énergie. Le calorimètre (11520 voies de détection) a été construit entre 2008 et fin 2010. L'installation du calorimètre auprès de l'expérience ALICE a été réalisée en deux phases, avec 40% des modules insérés mi-2009 et le reste en janvier 2011. Le groupe ALICE du LPSC est actuellement engagé dans une extension du calorimètre dont la construction devrait s'étaler sur les deux années à venir. Il est impliqué fortement dans l'assemblage, les tests et la calibration des super-modules, qui sont réalisés en collaboration avec les services d'instrumentation et d'électronique au sein de notre laboratoire. Le groupe est également impliqué dans l'élaboration du système de déclenchement de niveau 1 pour la détection des jets de grande énergie avec la réalisation et la mise en oeuvre d'une électronique dédiée en collaboration avec le service d'électronique.

Depuis le démarrage du LHC fin 2009, le groupe ALICE du LPSC est fortement impliqué dans l'analyse des premières données de physique. Il a contribué à la calibration finale du calorimètre avec l'analyse des pions neutres à partir des photons de décroissance. De plus, le groupe est engagé dans les mesures de sections efficaces de production des pions neutres en collisions protons-protons et plomb-plomb. Le groupe travaille également sur les mesures de corrélation photons-hadrons ainsi que sur le déclenchement des jets.

Annexe A

Accord du Conseil d'Unité du laboratoire

Le Conseil d'Unité du LPSC a approuvé la demande de passage Tier 2 du noeud de grille du LPSC le 20 mai 2011 dans les termes suivants : « Le CU du LPSC a approuvé le passage Tier 2 de son noeud de grille. Il tient à souligner la qualité du travail accompli et le fait que cette demande est justifiée du fait de l'enjeu que cela représente pour les deux expériences LHC du laboratoire (ATLAS et ALICE). Il note l'intérêt de disposer d'un noeud de grille au LPSC pour d'autres activités au LPSC (physique des réacteurs) et au-delà. Pour cela il apparaît naturel que des investissements puissent être faits par le LPSC dans ce cadre, mais demande que cet engagement puisse être mis en regard avec les autres demandes et examiné en CU en cas de difficultés financières fortes. »

Avis du comité de direction de LCG-France et des représentants des expériences ATLAS et ALICE

Le comité de direction de LCG-France s'est réuni le 10 juin 2011 et a examiné la demande de passage au niveau T2 du site de grille du LPSC.

Les représentants des expériences ATLAS et ALICE ont émis un avis très favorable au passage T2 du site en soulignant le bon fonctionnement du site et l'implication de son personnel.

Après consultation des avis du conseil de laboratoire du LPSC, des deux expériences ATLAS et ALICE et des membres du comité de direction en date du 10 juin 2011, LCG-France donne un avis très favorable au passage de T3 à T2 du site du LPSC.


Hervé Panetto
email: herve.panetto@univ-lorraine.fr

Ricardo Jardim-Goncalves

Arturo Molina
email: armolina@itesm.mx

of the IFAC TC 5.3 « Enterprise Integration and Networking » Enterprise Integration and Networking: theory and practice

Keywords: Enterprise Architecture, Enterprise Integration, Enterprise Interoperability, Enterprise Networking

Research and technological developments in Enterprise Integration and Networking requires identifying achievements, challenges and trends in order to establish a set of coherent vision and roadmap for future research. This paper analysis and discusses on recent achievements and future trends on research for Enterprise Integration and Networking solutions, identifying principal challenges for this research area. Such challenges are then analysed with regard to the contributions of this special issue, organised with extended papers selected by the IFAC TC 5.3 and presented at the

INTRODUCTION

In the Network-driven Economy, Enterprise Integration and Enterprise Interoperability solutions co-exist with each other to achieve the true: "Networked Enterprise" ecosystem. To be successful at integrating a pool of organisations and their related support institutions in a dynamic business ecosystem, four major scientific disciplines: Enterprise Architecture, Enterprise Integration, Enterprise Interoperability and Enterprise Networking, are working in providing organisations with the suitable technical and managerial solutions to support their different forms of business collaboration. This issue of the journal focuses on presenting novel research achievements of the scientific community to breakdown the organisational and technological barriers to improve the synergy within the enterprise and among enterprises based on enterprise modelling, architectural and ontological approaches to support enterprises collaboration in networked environments.

Enterprise Integration involves breaking down organizational barriers to improve synergy within the enterprise, so that business goals are achieved in a more productive and efficient way. Collaboration is necessary for enterprises to prosper in the current extreme dynamic and heterogeneous business ecosystems. Enterprise integration, interoperability and networking are the major disciplines that have studied how to do companies to collaborate and communicate in the most effective way. These disciplines are well-established and are supported by international conferences (e.g., EI2N, I-ESA, INCOM), research groups (e.g., IFAC TC 5.3 "Enterprise Integration and Networking", IFIP TC5 "Information Technology Application"), task forces (e.g., European Commission FInES cluster) and governmental projects (e.g., many all over the world where different domains of knowledge have been considered from different points of views and towards a variety of objectives at technological, managerial and organizational levels).

The past decade of enterprise integration research and industrial implementation has seen the emergence of important new research areas, such as "interoperability" and "networking", which involve breaking down organizational barriers to improve synergy within the enterprise and among enterprises. The ambition to achieve dynamic and effective cooperation of enterprises within networks of companies requires the improvement of existing, or the development of new theories, frameworks and technologies embracing Enterprise Modelling, Architectures, and Semantic Interoperability principles as essential pillars supporting the achievement of Enterprise Integration and Interoperability.

Moreover, organizations wish to adapt themselves according to the market demands and the availability of new systems and applications. Adaptation brings complexity, processes, models and semantics change, where heterogeneity of applications and data is present, mostly resulting in the loss of stability of the enterprise interoperable environment through failure of harmonization. These facts introduce the new concept of "sustainable interoperability". Sustainable interoperability is a new research dimension into the interoperability of enterprise systems and applications domain that is looking for novel strategies, methods and tools to maintain and sustain the interoperability of enterprise systems in networked environments in the advent of their dynamics.

The papers published in this section of the IFAC Annual Reviews in Control (ARC) have been selected and extended from the two tracks organised by the IFAC TC 5.3 "Enterprise Integration and Networking" held during the 14 th IFAC symposium on Information Control Problems in Manufacturing, Bucharest, Romania, May 23-15 2012. Most of the sessions of these tracks have been organised by volunteers, members of the IFAC TC 5.3, who have dedicated a big amount of their time to run successful sessions during the symposium. We would like to thank them for their involvement and dedicated effort to attract authors and to ensure their sound scientific contributions for the advances beyond the state-of-the-art in the research area of Enterprise Integration and Networking.

THEORETICAL AND PRACTICAL CONTRIBUTIONS

During the last years the research community has been developing solutions and publishing results contributing for the technical and scientific advancement of the Enterprise Integration and Networking research area. This work has been guided by identified major research challenges that have been worked out by the research community itself, assuring that research and development covers the main enterprise needs on integration and networking, and the solutions developed on the edge of the state-of-the-art are effective.

On this purpose, [START_REF] Panetto | Enterprise Integration and Interoperability in Manufacturing Systems: trends and issues[END_REF] analysed, characterised and discussed on major research challenges for Enterprise Integration and Interoperability. Also, during the last years the Research Roadmap developed with the support of the European Commission Future Internet Enterprise Systems (FInES) cluster has been of reference for Enterprise Network research area.

The papers selected for this special section of ARC respond to these identified research challenges, providing theoretical and practical central contributions from research and development on the edge of the state of the art. Table 1 identifies the main contributions that each paper provide on the Research Challenges for Enterprise Integration and Interoperability characterised by [START_REF] Panetto | Enterprise Integration and Interoperability in Manufacturing Systems: trends and issues[END_REF]. The Grand Challenge 6 "Sustainability of Enterprise Interoperability" is introduced as a novel dare that the research community has to address to meet the requirements for adaptation of the enterprise systems and application in the advent of the networked environment dynamics, towards a complete lifecycle management of enterprise interoperability networked ecosystems at business, knowledge, applications and communications levels.

Contributions in the business area

One of the major problems identified today concerning Enterprise Integration and Networking is related with the sustainability of the interoperable global environment once an integrated solution is achieved. With time, the applications and processes change, new parties join or leave the network, and this dynamic creates interoperability breakdown, disabling the already established global seamless operating environment. One of the principal reasons for this happening is that solutions are typically developed unilaterally, without a thoughtful joint analysis and decision, which makes difficult to resume the globally interoperable stage in the advent of individual or networked environment changes.

The frequent business changes disturb the interoperability links between the enterprises, leading to periods of adaptation where business operation is reduced or even not possible. The urge to rapidly regain interoperability often leads to unfounded, poorly-chosen solutions, which lead to inefficiency and deep rework. Thus, to have a strong interoperable environment requires performing constant, periodic maintenance operations in order to adapt enterprises to their surrounding ecosystem. This leads to the need for negotiations towards the achievement of Sustainable Enterprise Interoperability (SEI) that should be supported by a framework that promotes continuous improvement and adaptation towards the management of interoperability on enterprise systems, and which has negotiations as a core mechanism to handle inconsistencies and solutions for the detected interoperability problems. Following this approach, enterprises shall become more adaptable to changes and external factors, consequently developing resilient and efficient interactions with its supply chain.

However, interoperability between the involved parties in a negotiation is often not reached or maintained due to failure in adapting to new requirements, parties or conditions. [START_REF] Cretan | NEGOSEIO: A Framework for Negotiations toward Sustainable Enterprise Interoperability[END_REF] propose NEGOSEIO, a Collaborative Framework for Sustainable Enterprise Interoperability, to solve interoperability discrepancies in enterprise interactions, allowing a sustainable interoperability networking environment along its life cycle. With NEGOSEIO, SEI is possible when constant and periodic monitoring and maintenance is performed to the interoperable environment, whenever negotiations are essential on complex business environments to reduce the time where there is no operation, and improve resource and time management. Integration of formal procedures for modelling, storing and documenting the negotiation activities allows an optimised analysis of the alternative solutions and by adding the analysis of lessons-learned on past activities leads to maximised negotiation results, stronger negotiation capabilities and relationships. The use of the NEGOSEIO adaptive platform, supported by a proper architecture and methodology that includes a formal negotiation model, results in a sustainable instrument for interoperability maintenance along the enterprise networked ecosystem life cycle. This favours its maintenance across time, enabling to reach and interoperate with more parties which lead to new business opportunities and to stronger and improved interactions.

Actually, interoperability is considered a challenge conditioning the success of the enterprises deployment. The deployment of new processes in a company results from a strategic decision, as it consists in the progressive modification of existing activities or in the addition of new ones considered as required and relevant to the business strategy. Hence, the introduction of new processes in an enterprise is a strategic decision that cannot fail considering the risks it implies, which are better the chances of success for the deployment whenever it is maximized the interoperability of entities involved or impacted by it. With such interoperability established, the risk of process rejection and resistance to change will be reduced, the transition period from deployment to a normal execution will be shortened, the more entities are interoperable the more the execution time of process activities is reduced, and a better interoperability of entities usually implies better business satisfaction since they will spend less time in non-added value activities for seamless operation.

To improve the level of interoperability of their systems and applications, enterprises must have a suitable methodology to evaluate it, also appropriate for the assessment of the interoperability of the networked enterprise environment where they will operate. [START_REF] Cornu | Customizable interoperability assessment methodology to support technical processes deployment in large companies[END_REF] propose an Interoperability Assessment Methodology (IAM) applicable to both organizations and single resources, to guide the selection and allocation of entities that are considered to take part in the new processes to be deployed, to localize interoperability difficulties and propose corrective actions, and to monitor the evolution of the interoperability of entities to ensure that corrective actions are effective and efficient. It characterises several interoperability assessment types and the entities to be assessed described in an Interoperability Assessment Matrix, conducting to the identification of the needs to be met by interoperability assessment solutions and tools.

IAM is supported by a meta-model that enables the complete management of the methodology process and procedures along its implementation, having the assessment methods mathematically formalised. The methodology enables an assessment before, during or after the beginning of business collaboration, and with a known or unknown partner. It is designed to be used by enterprises with the support of a computational tool, and usable for prevention, detection and correction of interoperability problems. IAM can be used as a basis to improve the interoperability of enterprises' resources, even regardless of a deployment effort, reducing the collaboration difficulties and increasing the global reactivity of the enterprises.

Contributions in the knowledge area

For an effective change of enterprise systems and applications, when operating individually or integrated in a networked environment, there is the need for a broad and seamless access to the information about the actual and demanded business scenarios. Therefore, it is needed to access to integrated information that is usually heterogeneous and stored in different data sources, causing semantics losses and an obstacle for the complete understanding of the relationships between the available information. In order to deal with these issues, a reference business ontology designed for information interoperability should be developed. Then, using an Ontology-Based System (OBS) with formalized knowledge for supporting the design of products and related manufacturing processes, would enable to exploit knowledge about the business in general, like product, processes, resources and sustainable manufacturing for proposing design and manufacturing process changes. In such reference ontology, concepts, processes and resources are associated to functions and enterprise knowledge, resulting in a knowledge-based system that, simulating a business enterprise expert, is able to automatically identify change opportunities and to propose alternatives on the basis of the existing business scenario. [START_REF] Giovannini | Ontology-Based System for supporting Manufacturing Sustainability[END_REF] propose a semantic model in an OBS to formalize and relate required concepts for making a knowledge-based system (KBS) able to support the identification of change opportunities and to support decision makers with the appropriate knowledge for the business and technological solutions deployment. In this proposal, a formal method equipped with a tool able to identify sustainable opportunities in product and manufacturing processes design is presented, including an extension of a product-centric ontology based on a functional vision. Concepts about all knowledge needed for this task are described and required information from heterogeneous sources to common semantics is aligned. However, some critical points are identified in this proposal, e.g., the definition of functions and the formalisation of business rules.

Nevertheless, to infer knowledge about functions and business solutions, it is needed a high level of detail for function effects definition and in product, processes and resources descriptions. Also, if it is required deployment of the ontology on more production sites, differences in the formalization of business constraints should be found. For instance, different applied standards lead to different interpretation of the business criteria, and thus an evolving ontology should be considered to manage the dynamics of this variability. Indeed, current alternative solutions are adapted to information but they ignore dynamics of enterprise business processes. The inference engine considers as feasible a solution that respects all functional constraints, but constraints of a local production site can limit its applicability. A noteworthy perspective should be the analysis of how the sustainability of solutions can be fitted to enterprises processes, to make possible a more effective and long term support for the deployment. This cannot be only an adaptation, but it requires strategies to enhance solutions effects on the basis of the knowledge about business processes, with output information seamlessly mapped directly with semantically enriched enterprises databases for further reduction of the deployment time.

The collaborative activity is synchronized and coordinated through a set of collaborative processes to build and maintain a shared representation of a business situation among all stakeholders, where the success of the collaboration process is linked with the share of knowledge between these actors to ensure a common understanding of the business scenario. However, the shared knowledge is composed of set of fragments that are created by various actors according to their expertise domain, and it is important to consider the consistency and common understanding of the interconnected data and information coming from different activities and managed by different and heterogeneous information systems. Thus, the knowledge sharing is constructed according to a set of cognitive and organizational processes, from the aggregation of different data and information defined in separate repositories, organized according to specific models and manipulated by different tools and actors.

To improve the consistency of the whole system design and the related data and information, knowledge crossing expertise must be tracked and formalized regarding a shared reference. Therefore, instead of defining a large reference models to which each expert refers to, a collaborative model should be defined enabling to seamless connect and integrate the data from each expert model. [START_REF] Belkadi | A meta-modelling framework for knowledge consistency in collaborative design[END_REF] propose a new meta-model based on a Model-Driven Engineering approach to manage the integration of heterogeneous experts' knowledge models in a collaborative process. The structure of the proposed knowledge meta-model is defined taking into account the complexity of knowledge definition and the properties of its components. This meta-model is split in a meta-model of data and in a collaboration meta-model, to represent the distinction between the core concepts of knowledge and other elements serving to represent the relation between these concepts, and between concepts of heterogeneous experts' models. This meta-modelling approach supports the integration of multi-knowledge models and guarantees data consistency in context of collaborative work. Its application consists of two steps, i.e., the mapping between the generic concepts of the knowledge meta-model and their related concepts in specific knowledge model, and the instantiation of the generic model in coherence with the mapping results.

An application of knowledge management in enterprise integration and networking is described in the case study presented by [START_REF] Zdravkovic | A case of using the Semantic Interoperability Framework for custom orthopaedic implants manufacturing[END_REF] that uses a Semantic Interoperability Framework (SIF) for custom orthopaedic implants manufacturing. Actually, the success of the orthopaedic predictive, preventive, diagnostic and therapeutic activities depends on the variety of factors, such as the availability of data about patient's condition, physician's knowledge and experience and availability of tangible resources (e.g., instruments, devices, fixtures, implants, software, etc.). However, surgeons are often not able to perform those activities efficiently because they are required right when decisions are to be made fast, and based on complete and updated information on the patient's condition. Those decisions assume the selection of appropriate actions, and are typically facilitated by the Enterprise Information Systems (EIS), which reflects two important issues that are identified in the daily practice in orthopaedics surgery, i.e., information interoperability and manufacturing of highly customized products.

The main features of the proposed infrastructure for custom orthopaedic implants manufacturing is based on the SIF, where the product infrastructure is represented by Description Logics (i.e., OWL based ontologies). The Enterprise Information Systems in the Enterprise Networked ecosystem is semantically interoperable, with each of the systems introduced into the collaborative network by its local ontology and using a central reference ontology with defined mappings between the concepts of different local ontologies. These mappings are stored in a form of SWRL (Semantic Web Rule Language) rules. The reference ontology then becomes a single point of access to the integrated ontology framework, and it is used to execute semantic queries within this framework. The local ontologies are explicit conceptualizations of the Enterprise Information Systems, generated by the method which performs the semantics analysis of the systems' database schema and transforms it into OWL ontology. The main components of the implementation architecture are Interoperability Service Utilities, which facilitate the registration of a local ontology represented by some domain or application ontology, the transformation of a local ontology from the sources of the implicit semantics, the semantic querying, the semantic reconciliation and the knowledge reasoning. Shared functions of the interoperable infrastructure are realized by the specific semantic applications, which formalize task-solving knowledge and use semantic queries to get necessary information from the integrated ontology framework, executed on the central ontology.

Contributions in the application and standardisation areas

Networked enterprises are required to continuously evolve so as to adequately respond to a dynamic, global and very competitive business environment, and this continuous change requirement affects the capacity of the enterprise to effectively interoperate internally and externally. Adding to this problem, the standards typically used as pillars for enterprise and network management and (inter)operation are themselves subject to continuous change and often bring their own interoperability, inconsistency and overlap problems. Thus, it is essential that such concerns are identified and addressed in a sustainable manner, taking into account the life cycles of the integrated networked environment and of all entities involved as their interoperability capabilities and requirements change along their lives. Standards interoperability is also an essential factor promoting ease of standalone or combined use, user acceptance and efficient administration and maintenance. As standards continuously evolve, adequate interoperability must be achieved but also maintained during their lives. Sustainable interoperability of standards involves a multitude of interdependent aspects and levels, reaching from infrastructure all the way to the organisational culture and background of the custodian work groups.

However, a large majority of the standards involve the work and consensus of experts that are typically volunteering their time and resources in the process, and the use of standards is regulated or mandated by government and private organisations and agencies. This means that most of the time companies must abide by the standards specified by the clients and in legal documents. Also, the problems of glossary consistency and overlap leading to low interoperability have been long recognised in the standards community. As a result, there have been occasional attempts to harmonise standards, with varying degrees of success. Typically, these attempts were lengthy and expensive endeavours restricted to a few standards. Actually, in the absence of a reference framework commonly agreed upon that can be used to reach common ground, harmonisation results in a political and lobbying exercise as all standards involved may be subjected to changes and naturally the custodian working groups of each participating standard are standing by their own work. [START_REF] Noran | Achieving a Sustainable Interoperability of Standards[END_REF] focuses on interoperability issues specific to standards and proposes a novel way forward based on principles tested in previous case studies combining elements from the Enterprise Interoperability, Architecture and Integration, Collaborative Networks and Artificial Intelligence bodies of knowledge. Based on the previous results and on-going research work, it is proposed a more structured and widely applicable approach to achieve sustainable consistency, redundancy elimination and interoperability. The creation of a common workplace driven by an intelligent structured repository allows a starting point to effectively address the problems identified, like interoperability-relevant elements (e.g., aspects, barriers) can be sourced by mapping and decomposing the mainstream interoperability frameworks (IFs) in respect to a reference framework. By a similar process, the repository is populated with elements sourced from standards, and rules can then be added to enable querying the repository and thus transforming it into a knowledge base. This proposal results in a system that addresses the above-mentioned aspects by combining concepts drawing from the Interoperability, Enterprise Integration, Collaborative Networks and Artificial Intelligence bodies of knowledge.

The transformation between formal models can be implemented to tackle this challenge, using modelmorphism to describe the transformations and meta-modelling to support the implementation and execution of tools for automatic model transformations. [START_REF] Soliman | Transformation of Function Block Diagrams to UPPAAL Timed: Automata for the Verification of Safety Applications[END_REF] propose the adoption of this methodology in a set of transformation rules defined for the automatic transformation of IEC 61131-3 function block based safety applications to UPPAAL timed automata models. These models are next used for the verification of the safety application, where both the source and the target domain models have been formally defined and these definitions are used for the formal definition of the transformation rules. Based on this methodology a tool for model transformation was developed using Java, and employed in various safety applications proving the efficiency of the transformation process.

3 TRENDS AND CONCLUSIONS [START_REF] Panetto | Enterprise Integration and Interoperability in Manufacturing Systems: trends and issues[END_REF] summarized the need for Enterprise Integration and Interoperability in Manufacturing Systems. In this special issue, this work was revised to reflect the actual trends and state of the art, and a new Grand Challenge was identified, i.e., Sustainability of Enterprise Interoperability. Thus, an additional area has been included in this contribution to complete all relevant challenges faced by this area of research, namely, "Sustainability of Enterprise interoperability", and now six Grand Challenges are classified according to the following areas(Table 1): 1. Collaborative Networked Organizations 2. Enterprise Modelling and Reference Models 3. Enterprise and Processes Models Interoperability 4. Validation, Verification, Qualification and Accreditation of Enterprise Models 5. Model Reuse and Repositories 6. Sustainability of Enterprise interoperability During last years, significant discussions and contributions have been published on these areas, where trends to be faced in order to tackle 2020 Manufacturing challenges and successfully design and creation of the true concept of "Networked Enterprise" ecosystem [START_REF] Romero | Next Generation Manufacturing Systems and the Virtual Enterprise[END_REF]. [START_REF] Panetto | Towards a Classification Framework for Interoperability of Enterprise Applications[END_REF] classified and developed the frameworks for analysing interoperability issues and the degree of interoperability/integration desired in a joint family of systems or units, driven by the underlying operational level of those systems. Jardim-Goncalves et al. ( 2012) elaborated a comprehensive analysis of the Systematisation of Interoperability Body of Knowledge as the basis for the foundation for Enterprise Interoperability as a science. The analysis about Interoperability Frameworks, Interoperability Theories and Interoperability Models are discussed in the presence of the state of the art, and it offers interesting insights regarding the current state of play on the systematization of Interoperability Body of Knowledge providing relevant perspectives about directions for future research and development in the field. The following are a summary of the trends that the authors have identified:

•

The need for design patterns and model-based components available as (commercial) building blocks to design, build, and reengineer large scale systems not only to support single Enterprise Integration but also helping at formally assessing interoperability barriers [START_REF] Yahia | Formal measures for semantic interoperability assessment in cooperative enterprise information systems[END_REF] in Collaborative Networked Organizations. Also, the value proposition on interoperability has been considered a focus for the targeting solution in the domain of Enterprise Integration and Networking [START_REF] Grilo | Value proposition on interoperability of BIM and collaborative working environments[END_REF] •

The creation of a standard, user-oriented, interface in the form of a unified enterprise modelling language (UEML) based on the previous consensus to be available on all commercial modelling tools [START_REF] Panetto | A Unified Enterprise Modeling Language for enhanced interoperability of Enterprise Models[END_REF] [START_REF] Anaya | The Unified Enterprise Modelling Language-Overview and further work[END_REF].

•

There are real enterprise modelling and simulation tools commercially available taking into account function, information, resource, organization, and financial aspects of an enterprise including human aspects, exception handling, and process coordination. Simulation tools need to be configurable, distributed, agent-based simulation tools [START_REF] Hall | The 2005 Enterprise Architecture, Process Modeling & Simulation Tools Report[END_REF].

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The application of reference models has been studied to have more experiences in the creation of a reference model for enterprise integration and networking towards the realization of Future Internet Enterprise Systems (FInES) [START_REF] Jardim-Goncalves | Systematisation of Interoperability Body of Knowledge: the foundation for Enterprise Interoperability as a science[END_REF]. Concerning Interoperability Frameworks, it is undisputable that there is maturity around in the current body of knowledge. Several authors have developed Enterprise and Government Interoperability specific frameworks, with more or less layers and variables, but overall most frameworks are structured similarly, considering the technological, business and organizational perspectives.

•

Reference architectures and methodologies, as MDA (Model driven Architecture) [START_REF] Frankel | Model Driven Architecture: Applying MDA to Enterprise Computing[END_REF] and SOA (Service Oriented architecture) [START_REF] Bell | Service-Oriented Modeling (SOA): Service Analysis, Design, and Architecture[END_REF], have been applied and used as a basis for the development of solution to support Enterprise Integration and Networking [START_REF] Jardim-Goncalves | Challenging the interoperability between computers in industry with MDA and SOA[END_REF]. Services and Servitization, are concepts that actually are considered pillar for the development of seamless solutions, contributing for easier and agile answers for many of the main interoperability problems identified.

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There are commercially available integration platforms and integrating infrastructures (in the form of packages of computer services) for plug-and-play solutions [START_REF] Daigneau | Service Design Patterns: Fundamental Design Solutions for SOAP/WSDL and RESTful Web Services[END_REF]. ARCON is an example of an architecture for collaborative networks [START_REF] Camarinha-Matos | Collaborative Networked Organizations -Concepts and practice in Manufacturing Enterprises[END_REF]).

•

A community with knowledge organisation based on ontologies will enable an increase in the computational intelligence of its information systems [START_REF] Sarraipa | MENTOR: an enabler for interoperable intelligent systems[END_REF]. However, due to the worldwide diversity of communities, a high number of knowledge representation elements, which are not semantically coincident, have appeared representing the same segment of reality, becoming a barrier to business communications. As future trend, it is foreseen the need for a methodology to support the development of a common reference ontology for a group of organisations sharing the same business domain. This methodology should be based on the mediator ontology (MO) concept, which assists the semantic transformations among each enterprise's ontology and the referential one. The MO enables each organisation to keep its own terminology, glossary and ontological structures, while providing seamless communication and interaction with the others.

•

The sustainability of the Enterprise Integration and Networking environments is a high-impact productivity factor both within the private and the public sector, affecting the overall quality, yield time and cost of transactions, as well as the design of manufacturing operations or digital public services. Future research in this area has to embrace the rationale and analysis of the results of the state of the art in this area, focusing on novel strategies, methods and tools to maintain and sustain the interoperability of enterprise systems in networked environments as they evolve with their environments.

Nevertheless, although there is a clearly established framework for enterprise interoperability to identify barriers, problems, issues and solutions to let enterprise interoperate in a structured and unambiguous way, the future trends in enterprise integration and enterprise modelling requires the creation of model-driven architectures that will allow users to design, implement and execute Total Interoperable Enterprise systems.

Regarding future work on this area, it is recommend that researchers abstain from creating more diversity in terms of approaches since the problem space is overall confined, and rather focus on the opportunity to further refine the details along with providing more clear detailed analysis about the interrelationships between the various variables on the different layers and perspectives and aim at delivering a systematized cause-effect framework.

ACKNOWLEDGEMENT

It has been a great pleasure to work with the international committee members of this special issue who played a valuable role in reviewing the submitted papers and contributed for the improving of the selected papers. We thank all of them for their dedication and interest. We take this opportunity to thank all authors for their contributions to this special section of the journal.