APPLICATIONS OF GRAPH THEORY FOR REUSE OF MODEL BASED SYSTEMS ENGINEERING DESIGN DATA

This dissertation contributes to systems engineering (SE) by introducing and demonstrating a novel graph-based design repository (GBDR) tool. GBDR enables engineers to leverage system design information from a heterogenous set of system models created using multiple model based systems engineering (MBSE) software tools as an integrated body of knowledge. Specifically, the research provides a set of approaches that allow the use of system models described in Systems Modeling Language and Lifecycle Modeling Language as an integrated body of design information. The coalesced body of system design information serves to support concept ideation and analysis within SE. The research accomplishes this by using a graph database to store system model information imported from digital artifacts created by MBSE tools and applying principles from graph theory and semantic web technologies to identify likely connections and equivalent concepts across system models, modeling languages, and metamodels. The research demonstrates that the presented tool can import, store, synthesize, search, display, distribute, and export information from multiple MBSE tools. As a practical demonstration, feasible subsystem design alternatives for a small unmanned aircraft system government reference architecture are identified from within a set of existing system models.OSD CAPECivilian, Office of the Secretary of DefenseApproved for public release. Distribution is unlimited

Pristup integraciji tehničkih prostora zasnovan na preslikavanjima iinženjerstvu vođenom modelima

In order to automate development of integration adapters in industrial settings, a model-driven approach to adapter specification is devised. In this approach, a domain-specific modeling language is created to allow specification of mappings between integrated technical spaces. Also proposed is the mapping automation engine that comprises reuse and alignment algorithms. Based on mapping specifications, executable adapters are automatically generated and executed. Results of approach evaluations indicate that it is possible to use a model-driven approach to successfully integrate technical spaces and increase the automation by reusing domainspecific mappings from previously created adapters.За потребе повећања степена аутоматизације развоја адаптера за интеграцију у индустријском окружењу, осмишљен је моделом вођен приступ развоју адаптера. У оквиру овог приступа развијен је наменски језик за спецификацију пресликавања између техничких простора који су предмет интеграције. Приступ обухвата и алгоритме за поравнање и поновно искориштење претходно креираних пресликавања са циљем аутоматизације процеса спецификације. На основу креираних пресликавања, могуће je аутоматски генерисати извршиви код адаптера. У испитивањима приступа, показано је да је могуће успешно применити моделом вођен приступ у интеграцији техничких простора као и да је могуће успешно повећати степен аутоматизације поновним искоришћењем претходно креираних пресликавања.Za potrebe povećanja stepena automatizacije razvoja adaptera za integraciju u industrijskom okruženju, osmišljen je modelom vođen pristup razvoju adaptera. U okviru ovog pristupa razvijen je namenski jezik za specifikaciju preslikavanja između tehničkih prostora koji su predmet integracije. Pristup obuhvata i algoritme za poravnanje i ponovno iskorištenje prethodno kreiranih preslikavanja sa ciljem automatizacije procesa specifikacije. Na osnovu kreiranih preslikavanja, moguće je automatski generisati izvršivi kod adaptera. U ispitivanjima pristupa, pokazano je da je moguće uspešno primeniti modelom vođen pristup u integraciji tehničkih prostora kao i da je moguće uspešno povećati stepen automatizacije ponovnim iskorišćenjem prethodno kreiranih preslikavanja

HybridMDSD: Multi-Domain Engineering with Model-Driven Software Development using Ontological Foundations

Software development is a complex task. Executable applications comprise a mutlitude of diverse components that are developed with various frameworks, libraries, or communication platforms. The technical complexity in development retains resources, hampers efficient problem solving, and thus increases the overall cost of software production. Another significant challenge in market-driven software engineering is the variety of customer needs. It necessitates a maximum of flexibility in software implementations to facilitate the deployment of different products that are based on one single core. To reduce technical complexity, the paradigm of Model-Driven Software Development (MDSD) facilitates the abstract specification of software based on modeling languages. Corresponding models are used to generate actual programming code without the need for creating manually written, error-prone assets. Modeling languages that are tailored towards a particular domain are called domain-specific languages (DSLs). Domain-specific modeling (DSM) approximates technical solutions with intentional problems and fosters the unfolding of specialized expertise. To cope with feature diversity in applications, the Software Product Line Engineering (SPLE) community provides means for the management of variability in software products, such as feature models and appropriate tools for mapping features to implementation assets. Model-driven development, domain-specific modeling, and the dedicated management of variability in SPLE are vital for the success of software enterprises. Yet, these paradigms exist in isolation and need to be integrated in order to exhaust the advantages of every single approach. In this thesis, we propose a way to do so. We introduce the paradigm of Multi-Domain Engineering (MDE) which means model-driven development with multiple domain-specific languages in variability-intensive scenarios. MDE strongly emphasize the advantages of MDSD with multiple DSLs as a neccessity for efficiency in software development and treats the paradigm of SPLE as indispensable means to achieve a maximum degree of reuse and flexibility. We present HybridMDSD as our solution approach to implement the MDE paradigm. The core idea of HybidMDSD is to capture the semantics of particular DSLs based on properly defined semantics for software models contained in a central upper ontology. Then, the resulting semantic foundation can be used to establish references between arbitrary domain-specific models (DSMs) and sophisticated instance level reasoning ensures integrity and allows to handle partiucular change adaptation scenarios. Moreover, we present an approach to automatically generate composition code that integrates generated assets from separate DSLs. All necessary development tasks are arranged in a comprehensive development process. Finally, we validate the introduced approach with a profound prototypical implementation and an industrial-scale case study.Softwareentwicklung ist komplex: ausführbare Anwendungen beinhalten und vereinen eine Vielzahl an Komponenten, die mit unterschiedlichen Frameworks, Bibliotheken oder Kommunikationsplattformen entwickelt werden. Die technische Komplexität in der Entwicklung bindet Ressourcen, verhindert effiziente Problemlösung und führt zu insgesamt hohen Kosten bei der Produktion von Software. Zusätzliche Herausforderungen entstehen durch die Vielfalt und Unterschiedlichkeit an Kundenwünschen, die der Entwicklung ein hohes Maß an Flexibilität in Software-Implementierungen abverlangen und die Auslieferung verschiedener Produkte auf Grundlage einer Basis-Implementierung nötig machen. Zur Reduktion der technischen Komplexität bietet sich das Paradigma der modellgetriebenen Softwareentwicklung (MDSD) an. Software-Spezifikationen in Form abstrakter Modelle werden hier verwendet um Programmcode zu generieren, was die fehleranfällige, manuelle Programmierung ähnlicher Komponenten überflüssig macht. Modellierungssprachen, die auf eine bestimmte Problemdomäne zugeschnitten sind, nennt man domänenspezifische Sprachen (DSLs). Domänenspezifische Modellierung (DSM) vereint technische Lösungen mit intentionalen Problemen und ermöglicht die Entfaltung spezialisierter Expertise. Um der Funktionsvielfalt in Software Herr zu werden, bietet der Forschungszweig der Softwareproduktlinienentwicklung (SPLE) verschiedene Mittel zur Verwaltung von Variabilität in Software-Produkten an. Hierzu zählen Feature-Modelle sowie passende Werkzeuge, um Features auf Implementierungsbestandteile abzubilden. Modellgetriebene Entwicklung, domänenspezifische Modellierung und eine spezielle Handhabung von Variabilität in Softwareproduktlinien sind von entscheidender Bedeutung für den Erfolg von Softwarefirmen. Zur Zeit bestehen diese Paradigmen losgelöst voneinander und müssen integriert werden, damit die Vorteile jedes einzelnen für die Gesamtheit der Softwareentwicklung entfaltet werden können. In dieser Arbeit wird ein Ansatz vorgestellt, der dies ermöglicht. Es wird das Multi-Domain Engineering Paradigma (MDE) eingeführt, welches die modellgetriebene Softwareentwicklung mit mehreren domänenspezifischen Sprachen in variabilitätszentrierten Szenarien beschreibt. MDE stellt die Vorteile modellgetriebener Entwicklung mit mehreren DSLs als eine Notwendigkeit für Effizienz in der Entwicklung heraus und betrachtet das SPLE-Paradigma als unabdingbares Mittel um ein Maximum an Wiederverwendbarkeit und Flexibilität zu erzielen. In der Arbeit wird ein Ansatz zur Implementierung des MDE-Paradigmas, mit dem Namen HybridMDSD, vorgestellt

Multi-paradigm modelling for cyber–physical systems: a descriptive framework

The complexity of cyber–physical systems (CPSS) is commonly addressed through complex workflows, involving models in a plethora of different formalisms, each with their own methods, techniques, and tools. Some workflow patterns, combined with particular types of formalisms and operations on models in these formalisms, are used successfully in engineering practice. To identify and reuse them, we refer to these combinations of workflow and formalism patterns as modelling paradigms. This paper proposes a unifying (Descriptive) Framework to describe these paradigms, as well as their combinations. This work is set in the context of Multi-Paradigm Modelling (MPM), which is based on the principle to model every part and aspect of a system explicitly, at the most appropriate level(s) of abstraction, using the most appropriate modelling formalism(s) and workflows. The purpose of the Descriptive Framework presented in this paper is to serve as a basis to reason about these formalisms, workflows, and their combinations. One crucial part of the framework is the ability to capture the structural essence of a paradigm through the concept of a paradigmatic structure. This is illustrated informally by means of two example paradigms commonly used in CPS: Discrete Event Dynamic Systems and Synchronous Data Flow. The presented framework also identifies the need to establish whether a paradigm candidate follows, or qualifies as, a (given) paradigm. To illustrate the ability of the framework to support combining paradigms, the paper shows examples of both workflow and formalism combinations. The presented framework is intended as a basis for characterisation and classification of paradigms, as a starting point for a rigorous formalisation of the framework (allowing formal analyses), and as a foundation for MPM tool development

Ontology-Driven Guidelines for Architecting Digital Twins in Factory Automation Applications

The rapid emerging technologies in various fields permitted the creation of simulation tools. These tools are designed to replicate physical systems in order to provide faster, cheaper and more detailed illustrative analysis of the physical system. In this regard, the concept of digital twins has been introduced to generally define these simulation tools. In fact, and according to the creator of the digital twin term Micheal Grieves, a digital twin is defined as a physical system, a digital replica of the physical system and information flow between the former parts. This definition is simple and generic for describing digital twins and yet, holistic. This broad definition creates a challenge for developers who target the development of such applications. Therefore, this paper presents a paradigm for architecting digital twins for manufacturing processes. The approach is inspired by the definitions of the ISA95 standard and the onion concept of computer applications to create multi-layer and multi-level concepts. Furthermore, and to satisfy the different required features by industries, the approach considers a multi-perspective concept that allows the separation of the digital twin views based on functionality. This paradigm aims at providing a modular, scalable, reusable, interoperable and composable approach for developing digital twins. Then, an implementation of the approach has been introduced using an ontology-based system and the IEC61499 standard. This implementation has been demonstrated on a discrete manufacturing assembly line.publishedVersionPeer reviewe

Agent-based management of clinical guidelines

Les guies de pràctica clínica (GPC) contenen un conjunt d'accions i dades que ajuden a un metge a prendre decisions sobre el diagnòstic, tractament o qualsevol altre procediment a un pacient i sobre una determinada malaltia. És conegut que l'adopció d'aquestes guies en la vida diària pot millorar l'assistència mèdica als pacients, pel fet que s'estandarditzen les pràctiques. Sistemes computeritzats que utilitzen GPC poden constituir part de sistemes d'ajut a la presa de decisions més complexos amb la finalitat de proporcionar el coneixement adequat a la persona adequada, en un format correcte i en el moment precís. L'automatització de l'execució de les GPC és el primer pas per la seva implantació en els centres mèdics.Per aconseguir aquesta implantació final, hi ha diferents passos que cal solucionar com per exemple, l'adquisició i representació de les GPC, la seva verificació formal, i finalment la seva execució. Aquesta Tesi està dirigida en l'execució de GPC i proposa la implementació d'un sistema multi-agent. En aquest sistema els diferents actors dels centres mèdics coordinen les seves activitats seguint un pla global determinat per una GPC. Un dels principals problemes de qualsevol sistema que treballa en l'àmbit mèdic és el tractament del coneixement. En aquest cas s'han hagut de tractar termes mèdics i organitzatius, que s'ha resolt amb la implementació de diferents ontologies. La separació de la representació del coneixement del seu ús és intencionada i permet que el sistema d'execució de GPC sigui fàcilment adaptable a les circumstàncies concretes dels centres, on varien el personal i els recursos disponibles.En paral·lel a l'execució de GPC, el sistema proposat manega preferències del pacient per tal d'implementar serveis adaptats al pacient. En aquesta àrea concretament, a) s'han definit un conjunt de criteris, b) aquesta informació forma part del perfil de l'usuari i serveix per ordenar les propostes que el sistema li proposa, i c) un algoritme no supervisat d'aprenentatge permet adaptar les preferències del pacient segons triï.Finalment, algunes idees d'aquesta Tesi actualment s'estan aplicant en dos projectes de recerca. Per una banda, l'execució distribuïda de GPC, i per altra banda, la representació del coneixement mèdic i organitzatiu utilitzant ontologies.Clinical guidelines (CGs) contain a set of directions or principles to assist the health care practitioner with patient care decisions about appropriate diagnostic, therapeutic, or other clinical procedures for specific clinical circumstances. It is widely accepted that the adoption of guideline-execution engines in daily practice would improve the patient care, by standardising the care procedures. Guideline-based systems can constitute part of a knowledge-based decision support system in order to deliver the right knowledge to the right people in the right form at the right time. The automation of the guideline execution process is a basic step towards its widespread use in medical centres.To achieve this general goal, different topics should be tackled, such as the acquisition of clinical guidelines, its formal verification, and finally its execution. This dissertation focuses on the execution of CGs and proposes the implementation of an agent-based platform in which the actors involved in health care coordinate their activities to perform the complex task of guideline enactment. The management of medical and organizational knowledge, and the formal representation of the CGs, are two knowledge-related topics addressed in this dissertation and tackled through the design of several application ontologies. The separation of the knowledge from its use is fully intentioned, and allows the CG execution engine to be easily customisable to different medical centres with varying personnel and resources.In parallel with the execution of CGs, the system handles citizen's preferences and uses them to implement patient-centred services. With respect this issue, the following tasks have been developed: a) definition of the user's criteria, b) use of the patient's profile to rank the alternatives presented to him, c) implementation of an unsupervised learning method to adapt dynamically and automatically the user's profile.Finally, several ideas of this dissertation are being directly applied in two ongoing funded research projects, including the agent-based execution of CGs and the ontological management of medical and organizational knowledge

A Model-Driven Approach for the Design, Implementation, and Execution of Software Development Methods

[EN] Software development projects are diverse in nature. For this reason, software companies are often forced to define their methods in-house. In order to define methods efficiently and effectively, software companies require systematic solutions that are built upon sound methodical foundations. Providing these solutions is the main goal of the Method Engineering discipline. Method Engineering is the discipline to design, construct, and adapt methods, techniques, and tools for the development of information systems. Over the last two decades, a lot of research work has been performed in this area. However, despite its potential benefits, Method Engineering is not widely used in industrial settings. Some of the causes of this reality are the high theoretical complexity of Method Engineering and the lack of adequate software support. In this thesis, we aim to mitigate some of the problems that affect Method Engineering by providing a novel methodological approach that is built upon Model-Driven Engineering (MDE) foundations. The use of MDE enables a rise in abstraction, automation, and reuse that allows us to alleviate the complexity of our Method Engineering approach. Furthermore, by leveraging MDE techniques (such as metamodeling, model transformations, and models at runtime), our approach supports three phases of the Method Engineering lifecycle: design, implementation, and execution. This is unlike traditional Method Engineering approaches, which, in general, only support one of these phases. In order to provide software support for our proposal, we developed a Computer-Aided Method Engineering (CAME) environment that is called MOSKitt4ME. To ensure that MOSKitt4ME offered the necessary functionality, we identified a set of functional requirements prior to developing the tool. Then, after these requirements were identified, we defined the architecture of our CAME environment, and, finally, we implemented the architecture in the context of Eclipse. The thesis work was evaluated by means of a study that involved the participation of end users. In this study, MOSKitt4ME was assessed by means of the Technology Acceptance Model (TAM) and the Think Aloud method. While the TAM allowed us to measure usefulness and ease of use in a subjective manner, the Think Aloud method allowed us to analyze these measures objectively. Overall, the results were favorable. MOSKitt4ME was highly rated in perceived usefulness and ease of use; we also obtained positive results with respect to the users' actual performance and the difficulty experienced.[ES] Los proyectos de desarrollo de software son diversos por naturaleza. Por este motivo, las compañías de software se ven forzadas frecuentemente a definir sus métodos de manera interna. Para poder definir métodos de forma efectiva y eficiente, las compañías necesitan soluciones sistemáticas que estén definidas sobre unos fundamentos metodológicos sólidos. Proporcionar estas soluciones es el principal objetivo de la Ingeniería de Métodos. La Ingeniería de Métodos es la disciplina que aborda el diseño, la construcción y la adaptación de métodos, técnicas y herramientas para el desarrollo de sistemas de información. Durante las dos últimas décadas, se ha llevado a cabo mucho trabajo de investigación en esta área. Sin embargo, pese a sus potenciales beneficios, la Ingeniería de Métodos no se aplica ampliamente en contextos industriales. Algunas de las principales causas de esta situación son la alta complejidad teórica de la Ingeniería de Métodos y la falta de un apropiado soporte software. En esta tesis, pretendemos mitigar algunos de los problemas que afectan a la Ingeniería de Métodos proporcionando una propuesta metodológica innovadora que está basada en la Ingeniería Dirigida por Modelos (MDE). El uso de MDE permite elevar el nivel de abstracción, automatización y reuso, lo que posibilita una reducción de la complejidad de nuestra propuesta. Además, aprovechando técnicas de MDE (como por ejemplo el metamodelado, las transformaciones de modelos y los modelos en tiempo de ejecución), nuestra aproximación da soporte a tres fases del ciclo de vida de la Ingeniería de Métodos: diseño, implementación y ejecución. Esto es a diferencia de las propuestas existentes, las cuales, por lo general, sólo dan soporte a una de estas fases. Con el objetivo de proporcionar soporte software para nuestra propuesta, implementamos una herramienta CAME (Computer-Aided Method Engineering) llamada MOSKitt4ME. Para garantizar que MOSKitt4ME proporcionaba la funcionalidad necesaria, definimos un conjunto de requisitos funcionales como paso previo al desarrollo de la herramienta. Tras la definción de estos requisitos, definimos la arquitectura de la herramienta CAME y, finalmente, implementamos la arquitectura en el contexto de Eclipse. El trabajo desarrollado en esta tesis se evaluó por medio de un estudio donde participaron usuarios finales. En este estudio, MOSKitt4ME se evaluó por medio del Technology Acceptance Model (TAM) y del método Think Aloud. Mientras que el TAM permitió medir utilidad y facilidad de uso de forma subjetiva, el método Think Aloud permitió analizar estas medidas objetivamente. En general, los resultados obtenidos fueron favorables. MOSKitt4ME fue valorado de forma positiva en cuanto a utilidad y facilidad de uso percibida; además, obtuvimos resultados positivos en cuanto al rendimiento objetivo de los usuarios y la dificultad experimentada.[CA] Els projectes de desenvolupament de programari són diversos per naturalesa. Per aquest motiu, les companyies es veuen forçades freqüenment a definir els seus mètodes de manera interna. Per poder definir mètodes de forma efectiva i eficient, les companyies necessiten solucions sistemàtiques que estiguin definides sobre uns fundaments metodològics sòlids. Proporcionar aquestes solucions és el principal objectiu de l'Enginyeria de Mètodes. L'Enginyeria de Mètodes és la disciplina que aborda el diseny, la construcció i l'adaptació de mètodes, tècniques i eines per al desenvolupament de sistemes d'informació. Durant les dues últimes dècades, s'ha dut a terme molt de treball de recerca en aquesta àrea. No obstant, malgrat els seus potencials beneficis, l'Enginyeria de Mètodes no s'aplica àmpliament en contextes industrials. Algunes de les principals causes d'aquesta situació són l'alta complexitat teòrica de l'Enginyeria de Mètodes i la falta d'un apropiat suport de programari. En aquesta tesi, pretenem mitigar alguns dels problemes que afecten a l'Enginyeria de Mètodes proporcionant una proposta metodològica innovadora que està basada en l'Enginyeria Dirigida per Models (MDE). L'ús de MDE ens permet elevar el nivell d'abstracció, automatització i reutilització, possibilitant una reducció de la complexitat de la nostra proposta. A més a més, aprofitant tècniques de MDE (com per exemple el metamodelat, les transformacions de models i els models en temps d'execució), la nostra aproximació suporta tres fases del cicle de vida de l'Enginyeria de Mètodes: diseny, implementació i execució. Açò és a diferència de les propostes existents, les quals, en general, només suporten una d'aquestes fases. Amb l'objectiu de proporcionar suport de programari per a la nostra proposta, implementàrem una eina CAME (Computer-Aided Method Engineering) anomenada MOSKitt4ME. Per garantir que MOSKitt4ME oferia la funcionalitat necessària, definírem un conjunt de requisits funcionals com a pas previ al desenvolupament de l'eina. Després de la definició d'aquests requisits, definírem la arquitectura de l'eina CAME i, finalment, implementàrem l'arquitectura en el contexte d'Eclipse. El treball desenvolupat en aquesta tesi es va avaluar per mitjà d'un estudi on van participar usuaris finals. En aquest estudi, MOSKitt4ME es va avaluar per mitjà del Technology Acceptance Model (TAM) i el mètode Think Aloud. Mentre que el TAM va permetre mesurar utilitat i facilitat d'ús de manera subjectiva, el mètode Think Aloud va permetre analitzar aquestes mesures objectivament. En general, els resultats obtinguts van ser favorables. MOSKitt4ME va ser valorat de forma positiva pel que fa a utilitat i facilitat d'ús percebuda; a més a més, vam obtenir resultats positius pel que fa al rendiment objectiu dels usuaris i a la dificultat experimentada.Cervera Úbeda, M. (2015). A Model-Driven Approach for the Design, Implementation, and Execution of Software Development Methods [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/53931TESI

A modeling language for multi-tenant data architecture evolution in cloud applications

Multi-tenancy enables efficient resource utilization by sharing application resources across multiple customers (i.e., tenants). Hence, applications built using this pat- tern can be offered at a lower price and reduce maintenance effort as less application instances and supporting cloud resources must be maintained. These properties en- courage cloud application providers to adopt multi-tenancy to their existing applications, yet introducing this pattern requires significant changes in the application structure to address multi-tenancy requirements such as isolation of tenants, extensibility of the application, and scalability of the solution. In cloud applications, the data layer is often the prime candidate for multi-tenancy, and it usually comprises a combination of different cloud storage solutions such as blob storage, relational and non-relational databases. These storage types are conceptually and tangibly divergent, each requiring its own partitioning schemes to meet multi-tenancy requirements. Currently, multi-tenant data architectures are implemented using manual coding methods, at times following guidance and patterns offered by cloud providers. However, such manual implementation approach tends to be time consuming and error prone. Several modeling methods based on Model-Driven Engineer- ing (MDE) and Software Product Line Engineering (SPLE) have been proposed to capture multi-tenancy in cloud applications. These methods mainly generate cloud deployment configurations from an application model, though they do not automate implementation or evolution of applications. This thesis aims to facilitate development of multi-tenant cloud data architectures using model-driven engineering techniques. This is achieved by designing and implementing a novel modeling language, CadaML, that provides concepts and notations to model multi-tenant cloud data architectures in an abstract way. CadaML also provides a set of tools to validate the data architecture and automatically produce corresponding data access layer code. The thesis demonstrates the feasibility of the modeling language in a practical setting and adequacy of multi-tenancy implementation by the generated code on an industrial business process analyzing application. Moreover, the modeling language is empirically compared against manual implementation methods to inspect its effect on developer productivity, development effort, reliability of the application code, and usability of the language. These outcomes provide a strong argument that the CadaML modeling language effectively mitigates the high overhead of manual implementation of multi-tenant cloud data layers, significantly reducing the required development complexity and time

Consistency Modeling in a Multi-Model Architecture : Integrate and Celebrate Diversity

Central to Model-Driven Engineering (MDE) is seeing models as objects that can be handled and organized into metamodel stacks and multi-model architectures. This work contributes with a unique way of doing consistency modeling where the involved models are explicitly organized in a multi-model architecture; a general model for creating multi-model architectures that allows semantics to be attached is defined and applied; explicit attachment of semantics is demonstrated by attaching Java classes that implement different instantiation semantics in order to realize the consistency modeling and the automatic generation of consistency data. The kind of consistency addressed concerns relations between data residing in legacy databases defined by different schemas. The consistency modeling is meant to solve the problem of exposing inconsistencies by relating the data. The consistency modeling combines in a practical way visual modeling and logic (OCL). The approach is not limited to exposing inconsistencies, but may also be used to derive more general information given one or more data sets. The consistency is modeled by defining a consistency model that relates elements of two given legacy models. The consistency model is expressed in a language specially designed for consistency modeling. The language allows definition of classes, associations and invariants expressed in OCL. The interpretation of the language is special: Given one conforming data set for each of the legacy models, the consistency model may then be automatically instantiated to consistency data that tells if the data sets are consistent or not. The invariants are used to decide what instances to generate when making the consistency data. The amount of consistency data to create is finite and limited by the given data sets. The consistency model is instantiated until no more elements can be added without breaking some invariant or multiplicity. The consistency data is presented as a model which can be investigated by the user