An Evaluation of Inter-Organizational Workflow Modelling Formalisms

This paper evaluates the dynamic aspects of the UML in the context of inter-organizational workflows. Two evaluation methodologies are used. The first one is ontological and is based on the BWW (Bunge-Wand-Weber) models. The second validation is based on prototyping and consists in the development of a workflow management system in the aerospace industry. Both convergent and divergent results are found from the two validations. Possible enhancements to the UML formalism are suggested from the convergent results. On the other hand, the divergent results suggest the need for a contextual specification in the BWW models. Ce travail consiste en une évaluation des aspects dynamiques du language UML dans un contexte de workflow inter-organisationnel. Le choix du language par rapport à d'autres est motivé par sa richesse grammaticale lui offrant une très bonne adaptation à ce contexte. L'évaluation se fait par une validation ontologique basée sur les modèles BWW (Bunge-Wand-Weber) et par la réalisation d'un prototype de système de gestion de workflows inter-organisationnels. À partir des résultats convergents obtenus des deux différentes analyses, des améliorations au formalisme UML sont suggérées. D'un autre coté, les analyses divergentes suggèrent une possibilité de spécifier les modèles BWW à des contextes plus particuliers tels que ceux des workflows et permettent également de suggérer d'autres améliorations possibles au langage.Ontology, Conceptual study, Prototype Validation, UML, IS development methods and tools., Ontologie, étude conceptuelle, validation du prototype, UML, méthodes et outils de développement IS

Engineering Agent Systems for Decision Support

This paper discusses how agent technology can be applied to the design of advanced Information Systems for Decision Support. In particular, it describes the different steps and models that are necessary to engineer Decision Support Systems based on a multiagent architecture. The approach is illustrated by a case study in the traffic management domain

XML content warehousing: Improving sociological studies of mailing lists and web data

In this paper, we present the guidelines for an XML-based approach for the sociological study of Web data such as the analysis of mailing lists or databases available online. The use of an XML warehouse is a flexible solution for storing and processing this kind of data. We propose an implemented solution and show possible applications with our case study of profiles of experts involved in W3C standard-setting activity. We illustrate the sociological use of semi-structured databases by presenting our XML Schema for mailing-list warehousing. An XML Schema allows many adjunctions or crossings of data sources, without modifying existing data sets, while allowing possible structural evolution. We also show that the existence of hidden data implies increased complexity for traditional SQL users. XML content warehousing allows altogether exhaustive warehousing and recursive queries through contents, with far less dependence on the initial storage. We finally present the possibility of exporting the data stored in the warehouse to commonly-used advanced software devoted to sociological analysis

Participatory modelling and simulation of the rice seed system in Northeast Thailand

D'importantes réformes sont en cours dans le système semencier thailandais. Dans ce contexte, une série d'ateliers de modélisation participative ont été organisée avec les acteurs du système pour éliciter les besoins et les processus de décision concernant les variétés de riz et l'approvisionnement en semences dans la province d'Ubon Ratchatani. Un modèle conceptuel UML a été produit et partiellement implémenté dans un modèle multi-agent. Le modèle multi-agent permet de simuler sur un pas de temps les besoins et l'allocation des semences des deux principales variétés de riz par les institution publiques, privées ou coopératives au niveau des villages, des districts et des provinces. Un prototype a été présenté et discuté avec les représentants des institutions principales concernées par la réforme en cours. Après cette validation par les usagers, des scénarios possibles ont été proposés pour être simulés avec les modèles multiagents et discutés. (Résumé d'auteur

User-centred design of flexible hypermedia for a mobile guide: Reflections on the hyperaudio experience

A user-centred design approach involves end-users from the very beginning. Considering users at the early stages compels designers to think in terms of utility and usability and helps develop the system on what is actually needed. This paper discusses the case of HyperAudio, a context-sensitive adaptive and mobile guide to museums developed in the late 90s. User requirements were collected via a survey to understand visitors’ profiles and visit styles in Natural Science museums. The knowledge acquired supported the specification of system requirements, helping defining user model, data structure and adaptive behaviour of the system. User requirements guided the design decisions on what could be implemented by using simple adaptable triggers and what instead needed more sophisticated adaptive techniques, a fundamental choice when all the computation must be done on a PDA. Graphical and interactive environments for developing and testing complex adaptive systems are discussed as a further step towards an iterative design that considers the user interaction a central point. The paper discusses how such an environment allows designers and developers to experiment with different system’s behaviours and to widely test it under realistic conditions by simulation of the actual context evolving over time. The understanding gained in HyperAudio is then considered in the perspective of the developments that followed that first experience: our findings seem still valid despite the passed time

Automating Security Risk and Requirements Management for Cyber-Physical Systems

Cyber-physische Systeme ermöglichen zahlreiche moderne Anwendungsfälle und Geschäftsmodelle wie vernetzte Fahrzeuge, das intelligente Stromnetz (Smart Grid) oder das industrielle Internet der Dinge. Ihre Schlüsselmerkmale Komplexität, Heterogenität und Langlebigkeit machen den langfristigen Schutz dieser Systeme zu einer anspruchsvollen, aber unverzichtbaren Aufgabe. In der physischen Welt stellen die Gesetze der Physik einen festen Rahmen für Risiken und deren Behandlung dar. Im Cyberspace gibt es dagegen keine vergleichbare Konstante, die der Erosion von Sicherheitsmerkmalen entgegenwirkt. Hierdurch können sich bestehende Sicherheitsrisiken laufend ändern und neue entstehen. Um Schäden durch böswillige Handlungen zu verhindern, ist es notwendig, hohe und unbekannte Risiken frühzeitig zu erkennen und ihnen angemessen zu begegnen. Die Berücksichtigung der zahlreichen dynamischen sicherheitsrelevanten Faktoren erfordert einen neuen Automatisierungsgrad im Management von Sicherheitsrisiken und -anforderungen, der über den aktuellen Stand der Wissenschaft und Technik hinausgeht. Nur so kann langfristig ein angemessenes, umfassendes und konsistentes Sicherheitsniveau erreicht werden. Diese Arbeit adressiert den dringenden Bedarf an einer Automatisierungsmethodik bei der Analyse von Sicherheitsrisiken sowie der Erzeugung und dem Management von Sicherheitsanforderungen für Cyber-physische Systeme. Das dazu vorgestellte Rahmenwerk umfasst drei Komponenten: (1) eine modelbasierte Methodik zur Ermittlung und Bewertung von Sicherheitsrisiken; (2) Methoden zur Vereinheitlichung, Ableitung und Verwaltung von Sicherheitsanforderungen sowie (3) eine Reihe von Werkzeugen und Verfahren zur Erkennung und Reaktion auf sicherheitsrelevante Situationen. Der Schutzbedarf und die angemessene Stringenz werden durch die Sicherheitsrisikobewertung mit Hilfe von Graphen und einer sicherheitsspezifischen Modellierung ermittelt und bewertet. Basierend auf dem Modell und den bewerteten Risiken werden anschließend fundierte Sicherheitsanforderungen zum Schutz des Gesamtsystems und seiner Funktionalität systematisch abgeleitet und in einer einheitlichen, maschinenlesbaren Struktur formuliert. Diese maschinenlesbare Struktur ermöglicht es, Sicherheitsanforderungen automatisiert entlang der Lieferkette zu propagieren. Ebenso ermöglicht sie den effizienten Abgleich der vorhandenen Fähigkeiten mit externen Sicherheitsanforderungen aus Vorschriften, Prozessen und von Geschäftspartnern. Trotz aller getroffenen Maßnahmen verbleibt immer ein gewisses Restrisiko einer Kompromittierung, worauf angemessen reagiert werden muss. Dieses Restrisiko wird durch Werkzeuge und Prozesse adressiert, die sowohl die lokale und als auch die großräumige Erkennung, Klassifizierung und Korrelation von Vorfällen verbessern. Die Integration der Erkenntnisse aus solchen Vorfällen in das Modell führt häufig zu aktualisierten Bewertungen, neuen Anforderungen und verbessert weitere Analysen. Abschließend wird das vorgestellte Rahmenwerk anhand eines aktuellen Anwendungsfalls aus dem Automobilbereich demonstriert.Cyber-Physical Systems enable various modern use cases and business models such as connected vehicles, the Smart (power) Grid, or the Industrial Internet of Things. Their key characteristics, complexity, heterogeneity, and longevity make the long-term protection of these systems a demanding but indispensable task. In the physical world, the laws of physics provide a constant scope for risks and their treatment. In cyberspace, on the other hand, there is no such constant to counteract the erosion of security features. As a result, existing security risks can constantly change and new ones can arise. To prevent damage caused by malicious acts, it is necessary to identify high and unknown risks early and counter them appropriately. Considering the numerous dynamic security-relevant factors requires a new level of automation in the management of security risks and requirements, which goes beyond the current state of the art. Only in this way can an appropriate, comprehensive, and consistent level of security be achieved in the long term. This work addresses the pressing lack of an automation methodology for the security-risk assessment as well as the generation and management of security requirements for Cyber-Physical Systems. The presented framework accordingly comprises three components: (1) a model-based security risk assessment methodology, (2) methods to unify, deduce and manage security requirements, and (3) a set of tools and procedures to detect and respond to security-relevant situations. The need for protection and the appropriate rigor are determined and evaluated by the security risk assessment using graphs and a security-specific modeling. Based on the model and the assessed risks, well-founded security requirements for protecting the overall system and its functionality are systematically derived and formulated in a uniform, machine-readable structure. This machine-readable structure makes it possible to propagate security requirements automatically along the supply chain. Furthermore, they enable the efficient reconciliation of present capabilities with external security requirements from regulations, processes, and business partners. Despite all measures taken, there is always a slight risk of compromise, which requires an appropriate response. This residual risk is addressed by tools and processes that improve the local and large-scale detection, classification, and correlation of incidents. Integrating the findings from such incidents into the model often leads to updated assessments, new requirements, and improves further analyses. Finally, the presented framework is demonstrated by a recent application example from the automotive domain

Infrastructure for the representation and electronic exchange of design knowledge

International audienceThis paper develops the concept of knowledge and its exchange using Semantic Web technologies. It points out that knowledge is more than information because it embodies the meaning, that is to say semantic and context. These characteristics will influence our approach to represent and to treat the knowledge. In order to be adopted, the developed system needs to be simple and to use standards. The goal of the paper is to find standards to model knowledge and exchange it with an other person. Therefore, we propose to model knowledge using UML models to show a graphical representation and to exchange it with XML to ensure the portability at low cost. We introduce the concept of ontology for organizing knowledge and for facilitating the knowledge exchange. Proposals have been tested by implementing an application on the design knowledge of a pen

Role-Based Access-Control for Databases

Liikudes üha enam paberivaba ari suunas, hoitakse üha enam tundlikku informatsiooni andmebaasides. Sellest tulenevalt on andmebaasid ründajatele väärtuslik sihtmärk. Levinud meetod andmete kaitseks on rollipõhine ligipääsu kontroll (role-based access control), mis piirab süsteemi kasutajate õiguseid vastavalt neile omistatud rollidele. Samas on turvameetmete realiseerimine arendajate jaoks aeganõudev käsitöö, mida teostatakse samaaegselt rakenduse toimeloogika realiseerimisega. Sellest tulenevalt on raskendatud turva vajaduste osas kliendiga läbirääkimine projekti algfaasides. See omakorda suurendab projekti reaalsete arenduskulude kasvamise riski, eriti kui ilmnevad turvalisuse puudujäägid realisatsioonis. Tänapäeva veebirakendustes andmebaasi ühenduste puulimine (connec-tion pooling ), kus kasutatakse üht ja sama ühendust erinevate kasutajate teenindamiseks, rikub vähima vajaliku õiguse printsiipi. Kõikidel ühendunud kasutajatel on ligipääs täpselt samale hulgale andmetele, mille tulemusena võib lekkida tundlik informatsioon (näiteks SQLi süstimine (SQL injection ) või vead rakenduses). Lahenduseks probleemile pakume välja vahendid rollipõhise ligipääsu kontorolli disainimiseks tarkvara projekteerimise faasis. Rollipõhise ligipääsu kontorolli modelleerimiseks kasutame UML'i laiendust SecureUML. Antud mudelist on võimalik antud töö raames valminud vahenditega genereerida koodi, mis kontrollib ligipääsu õiguseid andmebaasi tasemel. Antud madaltasemekontroll vähendab riski, et kasutajad näevad andmeid, millele neil ligipääsu õigused puuduvad. Antud töös läbiviidud uuring näitas, et mudelipõhine turvalisuse arendamise kvaliteet on kõrgem võrreldes programmeerijate poolt kirjutatud koodiga. Kuna turvamudel on loodud projekteerimise faasis on selle semantiline täielikkus ja korrektsus kõrge, millest tulenevalt on seda kerge lugeda ja muuta ning seda on lihtsam kasutada arendajate ja klientide vahelises suhtluses.With the constant march towards a paperless business environment, database systems are increasingly being used to hold more and more sensitive information. This means they present an increasingly valuable target for attackers. A mainstream method for information system security is Role-based Access Control (RBAC), which restricts system access to authorised users. However the implementation of the RBAC policy remains a human intensive activity, typically, performed at the implementation stage of the system development. This makes it difficult to communicate security solutions to the stakeholders earlier and raises the system development cost, especially if security implementation errors are detected. The use of connection pooling in web applications, where all the application users connect to the database via the web server with the same database connection, violates the the principle of minimal privilege. Every connected user has, in principle, access to the same data. This may leave the sensitive data vulnerable to SQL injection attacks or bugs in the application. As a solution we propose the application of the model-driven development to define RBAC mechanism for data access at the design stages of the system development. The RBAC model created using the SecureUML approach is automatically translated to source code, which implements the modelled security rules at the database level. Enforcing access-control at this low level limits the risk of leaking sensitive data to unauthorised users. In out case study we compared SecureUML and the traditional security model, written as a source code, mixed with business logic and user-interface statements. The case study showed that the model-driven security development results in significantly better quality for the security model. Hence the security model created at the design stage contains higher semantic completeness and correctness, it is easier to modify and understand, and it facilitates a better communication of security solutions to the system stakeholders than the security model created at the implementation stage