Combining petri nets and uml for model-based software engineering

UML is by far the most widely used modelling language used nowadays in software engineering, due to its large scope and its wide tool support. This software standard offers many diagrams that cover all typical perspectives for describing and modelling the software systems under consideration. Among those diagrams, UML includes diagrams (activity diagram, state machine diagram, use case diagrams, and the interaction diagrams) for describing the behaviour (or functionality) of a software system. Petri nets constitute a well-proven formal modelling language, suitable for describing the behaviour of systems with characteristics like concurrency, distribution, resource sharing, and synchronisation. Thus, one may question why not combining some UML diagrams with Petri nets for effectively supporting the activities of the software engineer. The usage of Petri nets for/in Software Engineering was addressed by several well-known researchers, like, for example, Reisig [6], Pezzè [1], Machado [5], and Kindler [4]. In this invited paper, we discuss some alternatives to introduce Petri nets into a UML-based software development process. In particular, we describe how Coloured Petri Net (CPN) models can be used to describe the set of scenarios associated with a given use case. We describe three different alternatives that can be adopted to achieve that purpose. The first approach, initially presented in [7], suggests a set of rules that allow software engineers to transform the behaviour described by a UML 2.0 sequence diagram into a CPN model. Sequence diagrams in UML 2.0 are much richer than those in UML 1.x, namely by allowing several traces to be combined in a unique diagram, using high-level operators over interactions. The main purpose of the transformation is to allow the development team to construct animations based on the CPN model that can be shown to the users or the clients in order to reproduce the expected scenarios and thus validate them. Thus, non-technical stakeholders are able to discuss and validate the captured requirements. The usage of animation is an important topic in this context, since it permits the user to discuss the system behaviour using the problem domain language. In the second approach, discussed in [3], we assume that developers specify the functionality of the system under consideration with use cases, each of which is described by a set of UML 2.0 sequence diagrams. For each use case, there should exist at least one sequence diagram that represents and describes its main scenario. Other sequence diagrams for the same use case are considered to be variations of the main scenario. The transformation approach allows the development team to interactively play or reproduce any possible run of the given scenarios. In particular, the natural characteristics of the CPN modelling language facilitate the representation of the hierarchy and concurrency constructs of sequence diagrams. The third alternative, considered in [2], is an improvement with respect to the previous approach and is targeted to reactive systems.We identify and justify two key properties that the CPN model must have, namely: (1) controller-and-environment-partitioned, which means constituting a description of both the controller and the environment, and distinguishing between these two domains and between desired and assumed behaviour; (2) use case-based, which means constructed on the basis of a given use case diagram and reproducing the behaviour described in accompanying scenario descriptions. We have demonstrated how this CPN model is useful for requirements engineering, since it provides a solid basis for addressing behavioural issues early in the development process, for example regarding concurrent execution of use cases and handling of failures

Herausforderungen in der Ingenieurbiologie - vom Ingenieurbauwesen zum Ingenieurbau- und planungswissen

Análise dos desafios actuais e futuros da Engenharia Natural em termos do aprofundamento dos domínios técnicos e científicos desta especialidade. Considerações sobre a evolução dos conceitos ecológicos e de planeamento e sua implicação nos domínios de actuação da Engenharia Natural

Uma nova ordem jurídica internacional? Novas do sistema de fontes. Contributos do direito internacional do ambiente

Não sendo certo que a nova ordem geopolítica internacional tenha sido capaz de dar origem a uma nova ordem jurídica internacional, é já possível encontrar indícios de mutação em certos institutos. É o caso do sistema de fontes de direito internacional, onde temos vindo a assistir a algumas alterações significativas em relação ao sistema clássico. À semelhança do que se passa no ordenamento jurídico interno, também no campo do direito internacional público são certos ramos que prenunciam as inovações que mais tarde se transformarão em regra geral. Para dar notícia das transformações em curso no sistema de fontes do direito internacional, escolhemos o direito internacional do ambiente como ramo precursor de tais mudanças

Tools and libraries to model and manipulate circular programs

This paper presents techniques to model circular lazy programs in a strict, purely functional setting. Circular lazy programs model any algorithm based on multiple traversals over a recursive data structure as a single traversal function. Such elegant and concise circular programs are defined in a (strict or lazy) functional language and they are transformed into efficient strict and deforested, multiple traversal programs by using attribute grammars-based techniques. Moreover, we use standard slicing techniques to slice such circular lazy programs. We have expressed these transformations as an Haskell library and two tools have been constructed: the HaCirctool that refactors Haskell lazy circular programs into strict ones, and the OCirctool that extends Ocaml with circular definitions allowing programmers to write circular programs in Ocaml notation, which are transformed into strict Ocaml programs before they are executed. The first benchmarks of the different implementations are presented and show that for algorithms relying on a large number of traversals the resulting strict, deforested programs are more efficient than the lazy ones, both in terms of runtime and memory consumption.(undefined

Sustentabilidade - a dimensão da liberdade e das responsabilidade

É feito um balanço do processo de ordenamento do território em Portugal à luz do conceito de sustentabilidade com particular enfoque no território urban

Interoperability between health information systems in the hospital context

The information systems had a positive effect on the health service by reducing the physical documentation, more available information to monitor the patient and safer data storage. On the other hand, there was a negative impact due to an increase of diverse systems operating which demanded more training and support to hospitals structure aligned with the lack of interoperability standards that promote the patient´s data sharing between them. Therefore, this dissertation focused on analysing the existent interoperability between information systems in the Portuguese health service, determine the key aspects to establish communication among them, and the consequences it has on the healthcare professional´s routines. Interviews were conducted with healthcare professionals and hospital suppliers to collect their experience on interacting with this technology, their opinion about the influence it has on the hospital´s routine, and the potential measures to improve the current situation. This research concluded that the lack of interoperability and an unfriendly interface generates a complex use of the systems with a high number of clicks and slower navigation to execute the tasks that can cause loss of time for healthcare professionals. Besides, the public hospital demonstrated to have a higher number of IS suppliers and lower levels of integration between systems compared with private hospitals. Lastly, it was demonstrated that an organisational culture oriented to the technology change and a strategic plan to adapt to the hospital's approach is necessary to a successful implementation of health information systems.Os sistemas de informação tiveram um efeito positivo no serviço de saúde com redução na documentação em papel, maior disponibilidade de informação sobre o paciente e segurança no armazenamento de dados. Por outro lado, houve um impacto negativo devido ao aumento na diversidade de sistemas a operar, que exigiram mais treino e apoio à estrutura hospitalar, associado à falta de padrões de interoperabilidade que promovam a partilha de dados do paciente. Assim, esta dissertação centra-se na análise da interoperabilidade existente entre os sistemas de informação no serviço de saúde português, em determinar os aspetos fundamentais para estabelecer a comunicação entre os mesmos e as consequências que têm na rotina do profissional de saúde. Foram realizadas entrevistas com profissionais da área e fornecedores hospitalares para recolher informação sobre a experiência na interação com esta tecnologia, a opinião sobre a influência que ela exerce na rotina hospitalar e as possíveis medidas para melhorar a atual situação. Esta investigação concluiu que a falta de interoperabilidade e uma interface pouco apelativo determinam um uso complexo destes sistemas com um elevado número de cliques e uma navegação mais lenta para executar as tarefas, que podem causar perda de tempo aos profissionais de saúde. Além disso, os hospitais públicos demonstram ter um maior número de fornecedores e menores níveis de integração entre os sistemas em comparação com os privados. Por fim, expõem-se que uma cultura organizacional direcionada para a mudança tecnológica e um plano estratégico de adaptação são necessários para o sucesso da implantação destes sistemas