Artifact-centric business process models in UML : specification and reasoning

Business processes are directly involved in the achievement of an organization's goals, and for this reason they should be performed in the best possible way. Modeling business processes can help to achieve this as, for instance, models can facilitate the communication between the people involved in the process, they provide a basis for process improvement and they can help perform process management. Processes can be modeled from many different perspectives. Traditional process modeling has followed the process-centric (or activity-centric) perspective, where the focus is on the sequencing of activities (i.e. the control flow), largely ignoring or underspecifying the data required by these tasks. In contrast, the artifact-centric (or data-centric) approach to process modeling focuses on defining the data required by the tasks and the details of the tasks themselves in terms of the changes they make to the data. The BALSA framework defines four dimensions which should be represented in any artifact-centric business process model: business artifacts, lifecycle, services (i.e. tasks) and associations. Using different types of models to represent these dimensions will result in distinct representations, whose differing characteristics (e.g. the degree of formality or understandability) will make them more appropriate for one purpose or another. Considering this, in the first part of this thesis we propose a framework, BAUML, for modeling business processes following an artifact-centric perspective. This framework is based on using a combination of UML and OCL models, and its goal is to have a final representation of the process which is both understandable and formal, to avoid ambiguities and errors. However, once a process model has been defined, it is important to ensure its quality. This will avoid the propagation of errors to the process's implementation. Although there are many different quality criteria, we focus on the semantic correctness of the model, answering questions such as "does it represent reality correctly?" or "are there any errors and contradictions in it?". Therefore, the second part of this thesis is concerned with finding a way to determine the semantic correctness of our BAUML models. We are interested in considering the BAUML model as a whole, including the meaning of the tasks. To do so, we first translate our models into a well-known framework, a DCDS (Data-centric Dynamic System) to which then modelchecking techniques can be applied. However, DCDSs have been defined theoretically and there is no tool that implements them. For this reason, we also created a prototype tool, AuRUS-BAUML, which is able to translate our BAUML models into logic and to reason on their semantic correctness using an existing tool, SVTe. The integration between AuRUS-BAUML and SVTe is transparent to the user. Logically, the thesis also presents the logic translation which is performed by the tool.Els processos de negoci estan directament relacionats amb els objectius de negoci, i per tant és important que aquests processos es duguin a terme de la millor manera possible. Optar per modelar-los pot ajudar a aconseguir-ho, ja que els models proporcionen nombrosos avantatges. Per exemple: faciliten la comunicació entre les parts involucrades en el procés, proporcionen una base a partir del qual millorar-lo, i poden ajudar a gestionar-lo. Els processos es poden modelar des de diferents perspectives. El modelat tradicional de processos s'ha basat molt en la perspectiva anomenada "process-centric" (centrada en processos) o "activity-centric" (centrada en activitats), que posa l'èmfasi en la seqüència d'activitats o tasques que s'han d'executar, ignorant en gran mesura les dades necessàries per dur a terme aquestes tasques. Per altra banda, la perspectiva "artifact-centric" (centrada en artefactes) o "data-centric" es basa en definir les dades que necessiten les tasques i els detalls de les tasques en si, representant els canvis que aquestes fan a les dades. El framework BALSA defineix quatre dimensions que haurien de representar-se en qualsevol model artifact-centric: els artefactes de negoci (business artifacts), els cicles de vida (lifecycles), els serveis (services) i les associacions (associations). Utilitzant diferents tipus de models per representar aquestes dimensions porta a obtenir diverses representacions amb característiques diferents. Aquesta varietat de característiques farà que els models resultants siguin més apropiats per un propòsit o per un altre. Considerant això, en la primera part d'aquesta tesi proposem un framework, BAUML, per modelar processos de negoci seguint una perspectiva artifact-centric. El framework es basa en utilitzar una combinació de models UML i OCL, i el seu objectiu és obtenir una representació final del procés que sigui a la vegada comprensible i formal, per tal d'evitar ambigüitats i errors. Un cop definit el procés, és important assegurar-ne la qualitat. Això evitarà la propagació d'errors a la implementació final del procés. Malgrat que hi ha molts criteris de qualitat diferents, ens centrarem en la correctesa semàntica del model, per respondre a preguntes com ara "representa la realitat correctament?" o "conté errors o contradiccions?". En conseqüència, la segona part d'aquesta tesi se centra en buscar una manera per determinar la correctesa semàntica d'un model BAUML. Ens interessa considerar el model com un tot, incloent el significat de les tasques (és a dir, el detall del que fan). Per aconseguir-ho, primer traduïm les tasques a un framework reconegut, DCDSs (Data-centric Dynamic Systems). Un cop obtingut, s'hi poden aplicar tècniques de model-checking per determinar si compleix certes propietats. Malauradament, els DCDSs s'han definit a nivell teòric i no hi ha cap eina que els implementi. Per aquest motiu, hem creat un prototip d'eina, AuRUS-BAUML, que és capaç de traduir els nostres models BAUML a lògica i aplicar-hi tècniques de raonament per determinar-ne la correctesa semàntica. Per la part de raonament, l'AuRUS-BAUML fa servir una eina existent, l'SVTe. La integració entre l'AuRUS-BAUML i l'SVTe és transparent de cara a l'usuari. Lògicament, la tesi també presenta la traducció a lògica que porta a terme l'eina

Artifact-centric business process models in UML : specification and reasoning

Business processes are directly involved in the achievement of an organization's goals, and for this reason they should be performed in the best possible way. Modeling business processes can help to achieve this as, for instance, models can facilitate the communication between the people involved in the process, they provide a basis for process improvement and they can help perform process management. Processes can be modeled from many different perspectives. Traditional process modeling has followed the process-centric (or activity-centric) perspective, where the focus is on the sequencing of activities (i.e. the control flow), largely ignoring or underspecifying the data required by these tasks. In contrast, the artifact-centric (or data-centric) approach to process modeling focuses on defining the data required by the tasks and the details of the tasks themselves in terms of the changes they make to the data. The BALSA framework defines four dimensions which should be represented in any artifact-centric business process model: business artifacts, lifecycle, services (i.e. tasks) and associations. Using different types of models to represent these dimensions will result in distinct representations, whose differing characteristics (e.g. the degree of formality or understandability) will make them more appropriate for one purpose or another. Considering this, in the first part of this thesis we propose a framework, BAUML, for modeling business processes following an artifact-centric perspective. This framework is based on using a combination of UML and OCL models, and its goal is to have a final representation of the process which is both understandable and formal, to avoid ambiguities and errors. However, once a process model has been defined, it is important to ensure its quality. This will avoid the propagation of errors to the process's implementation. Although there are many different quality criteria, we focus on the semantic correctness of the model, answering questions such as "does it represent reality correctly?" or "are there any errors and contradictions in it?". Therefore, the second part of this thesis is concerned with finding a way to determine the semantic correctness of our BAUML models. We are interested in considering the BAUML model as a whole, including the meaning of the tasks. To do so, we first translate our models into a well-known framework, a DCDS (Data-centric Dynamic System) to which then modelchecking techniques can be applied. However, DCDSs have been defined theoretically and there is no tool that implements them. For this reason, we also created a prototype tool, AuRUS-BAUML, which is able to translate our BAUML models into logic and to reason on their semantic correctness using an existing tool, SVTe. The integration between AuRUS-BAUML and SVTe is transparent to the user. Logically, the thesis also presents the logic translation which is performed by the tool.Els processos de negoci estan directament relacionats amb els objectius de negoci, i per tant és important que aquests processos es duguin a terme de la millor manera possible. Optar per modelar-los pot ajudar a aconseguir-ho, ja que els models proporcionen nombrosos avantatges. Per exemple: faciliten la comunicació entre les parts involucrades en el procés, proporcionen una base a partir del qual millorar-lo, i poden ajudar a gestionar-lo. Els processos es poden modelar des de diferents perspectives. El modelat tradicional de processos s'ha basat molt en la perspectiva anomenada "process-centric" (centrada en processos) o "activity-centric" (centrada en activitats), que posa l'èmfasi en la seqüència d'activitats o tasques que s'han d'executar, ignorant en gran mesura les dades necessàries per dur a terme aquestes tasques. Per altra banda, la perspectiva "artifact-centric" (centrada en artefactes) o "data-centric" es basa en definir les dades que necessiten les tasques i els detalls de les tasques en si, representant els canvis que aquestes fan a les dades. El framework BALSA defineix quatre dimensions que haurien de representar-se en qualsevol model artifact-centric: els artefactes de negoci (business artifacts), els cicles de vida (lifecycles), els serveis (services) i les associacions (associations). Utilitzant diferents tipus de models per representar aquestes dimensions porta a obtenir diverses representacions amb característiques diferents. Aquesta varietat de característiques farà que els models resultants siguin més apropiats per un propòsit o per un altre. Considerant això, en la primera part d'aquesta tesi proposem un framework, BAUML, per modelar processos de negoci seguint una perspectiva artifact-centric. El framework es basa en utilitzar una combinació de models UML i OCL, i el seu objectiu és obtenir una representació final del procés que sigui a la vegada comprensible i formal, per tal d'evitar ambigüitats i errors. Un cop definit el procés, és important assegurar-ne la qualitat. Això evitarà la propagació d'errors a la implementació final del procés. Malgrat que hi ha molts criteris de qualitat diferents, ens centrarem en la correctesa semàntica del model, per respondre a preguntes com ara "representa la realitat correctament?" o "conté errors o contradiccions?". En conseqüència, la segona part d'aquesta tesi se centra en buscar una manera per determinar la correctesa semàntica d'un model BAUML. Ens interessa considerar el model com un tot, incloent el significat de les tasques (és a dir, el detall del que fan). Per aconseguir-ho, primer traduïm les tasques a un framework reconegut, DCDSs (Data-centric Dynamic Systems). Un cop obtingut, s'hi poden aplicar tècniques de model-checking per determinar si compleix certes propietats. Malauradament, els DCDSs s'han definit a nivell teòric i no hi ha cap eina que els implementi. Per aquest motiu, hem creat un prototip d'eina, AuRUS-BAUML, que és capaç de traduir els nostres models BAUML a lògica i aplicar-hi tècniques de raonament per determinar-ne la correctesa semàntica. Per la part de raonament, l'AuRUS-BAUML fa servir una eina existent, l'SVTe. La integració entre l'AuRUS-BAUML i l'SVTe és transparent de cara a l'usuari. Lògicament, la tesi també presenta la traducció a lògica que porta a terme l'eina.Postprint (published version

Reasoning on the usage control security policies over data artifact business process models

The inclusion of security aspects in organizations is a crucial aspect to ensure compliance with both internal and external regulations. Business process models are a well-known mechanism to describe and automate the activities of the organizations, which should include security policies to ensure the correct performance of the daily activities. Frequently, these security policies involve complex data which cannot be represented using the standard Business Process Model Notation (BPMN). In this paper, we propose the enrichment of the BPMN with a UML class diagram to describe the data model, that is also combined with security policies defined using the UCONABC framework annotated within the business process model. The integration of the business process model, the data model, and the security policies provides a context where more complex reasoning can be applied about the satisfiability of the security policies in accordance with the business process and data models. To do so, wetransform the original models, including security policies, into the BAUML framework (an artifact-centric approach to business process modelling). Once this is done, it is possible to ensure that there are no inherent errors in the model (verification) and that it fulfils the business requirements (validation), thus ensuring that the business process and the security policies are compatible and that they are aligned with the business security requirements.This work has been supported by Project PID2020-112540RB-C44 funded by MCIN/AEI/ 10.13039/501100011033, Project TIN2017-87610-R funded by MCIN/AEI/10.13039/501100011033 and FEDER “Una manera de hacer Europa”, Project 2017-SGR-1749 by the Generalitat de Catalunya, Projects COPERNICA (P20 01224) and METAMORFOSIS by the Junta de Andalucía.Peer ReviewedPostprint (published version

CAViT: a Consistency Maintenance Framework based on Transformation Contracts

Design by contract is a software correctness methodology for procedural and object-oriented software. It relies on logical assertions to detect implementation mistakes at run-time or to proof the absence thereof at compile-time. Design by contract has found a new application in model driven engineering, a methodology that aims to manage the complexity of frameworks by relying on models and transformations. A ``transformation contract\u27\u27 is a pair of constraints that together describe the effect of a transformation rule on the set of models contained in its transformation definition: the postcondition describes the model consistency state that the rule can establish provided that its precondition is satisfied. A transformation contract of a rule can be maintained automatically by calling the rule (1) as soon as the invariant corresponding to its postcondition is violated and (2) provided that its precondition is satisfied. Domain specific visual languages can facilitate the implementation of the actual transformation rules since they hide the complexity of graph transformation algorithms and standards for tool interoperability. In this talk, we describe CAViT: a framework that integrates a visual model transformation tool with a design by contract tool by relying on OMG standards such as UML, OCL and MOF

Applying Software Product Lines to Build Autonomic Pervasive Systems

In this Master Thesis, we have proposed a model-driven Software Product Line (SPL) for developing autonomic pervasive systems. The work focusses on reusing the Variability knowledge from the SPL design to the SPL products. This Variability knowledge enables SPL products to deal with adaptation scenarios (evolution and involution) in an autonomic way.Cetina Englada, C. (2008). Applying Software Product Lines to Build Autonomic Pervasive Systems. http://hdl.handle.net/10251/12447Archivo delegad

Trust-based trade

Weak enforcement of international contracts can substantially reduce international trade. We develop a model where agents build reputations to overcome the difficulties that this institutional failure causes in a context of incomplete information. The model describes the interplay between institutional quality, reputations and the dynamics of international trade. We find that the conditional probability that a firm will stop exporting decreases and its foreign sales increase as the firm acquires greater export experience. The reason is that the informational costs that an exporter faces fall as the exporter becomes more confident about the reliability of its distributor. An improvement in the institutional quality of a country affects its imports through several distinct channels, as it changes the incentives of both current and potential exporters. Trade liberalization induces current exporters to increase their sales. It could induce entry as well, but this will happen only when the initial tariff is high and/or the institutional quality of the country is low