Do Models Improve the Understanding of Safety Compliance Needs?: Insights from a Pilot Experiment

Context. Many critical systems must meet safety compliance needs from safety standards. These standards are usually large textual documents whose compliance needs can be hard to understand. As a solution, the use of models has been proposed. Goal. We aim to provide evidence of the extent to which models improve the understanding of safety compliance needs. Method. We designed an experiment and ran a pilot to study the effectiveness, efficiency, and perceived benefits of understanding these needs, with the text of standards and with models in the form of UML object diagrams. Results. The overall results from 15 Bachelor students show that the effectiveness of understanding safety compliance needs increases very little with models (2%), and the efficiency even decreases (24%). Nonetheless, the results improve when the potential complexity in navigating the models is taken into account (15% effectiveness increase). The students find benefits in using the models but most consider that the models are hard to understand. Conclusions. The extent to which models improve the understanding of safety compliance needs seems to be lower than what the research community expects. New studies are necessary to confirm our initial insights.European CommissionThe research leading to this paper has received funding from the AMASS project (H2020-ECSEL grant agreement no 692474; Spain’s MINECO ref. PCIN-2015-262) and the AMoDDI project (Ref. 11130583)

UML 2.0 BASED ROUND TRIP ENGINEERING FRAMEWORK FOR THE DEVELOPMENT OF SPF BASED SECURE APPLICATION

This research paper proposes the UML 2.0 based framework for round-trip engineering and use of Security Performance Flexibility model to keep high security in web applications. This model allows system administrators to skip or disable some unnecessary security checks in trusted operating systems through which, they can effectively balance their performance needs without compromising the security of the system. For example, the system admin can tell that video on demand server is allowed to skip only security checks on reading files, while the database server is allowed to skip only security checks on seeking files. Which operation is needed to be skipped and, which operation is not needed to be skipped is very much subjective in nature, this will depend upon the user’s requirement and the particular application’s requirement. The selection of these operations for a particular application is the part of software requirement elicitation process. This UML 2.0 based research work proposes Object-Oriented class-based software development, source code generation in C++ and the integration of security engineering into a model-driven software development. On this source code, Halstead software science measures, etc., can be applied. This helps developers in code restructuring; identify probable bugs or deficiencies for probable improvements and helps from the analysis phase to the maintenance phase

Ontology-based reasoning for entity-relationship data model semantic evaluation

Konceptualno modeliranje je jedna od najbitnijih aktivnosti u fazi modeliranja informacionog sustava najčešće prezentirana modelom entiteta-poveznika. Ovaj rad predstavlja sustav za semantičko evaluiranje modela entiteta-poveznika koji se bazira na komparaciji elemenata ontologije i modela podataka. Ovaj pristup je baziran na formalizaciji domenske ontologije i modela podataka u formu predikatskog računa koji je pogodan za rasuđivanje. Definiran je skup pravila rasuđivanja za mapiranje ontologije u model podataka. Ceo postupak je empirijski verificiran i potvrđen. Za ovu svrhu je razvijen softverski alat koji ontologiju i model podataka transformira u predikatski oblik i zatim u skup Prologolikih klauzula. Nakon integriranja ovih klauzula i pravila uporabljen je Prolog sustav za rasuđivanje sa ciljem da se kvantitativno izrazi kvalitet modela podataka sa odgovarajućom metrikom.Conceptual modeling is one of the most important activities in the modeling phase of information systems development most commonly presented by entity-relationship data model. This paper presents a system for entity-relationship data model semantic evaluation that is based on comparing ontology with data model elements. This approach is based on domain ontology and data model formalization at predicate calculus form that is suitable for reasoning. A set of reasoning rules for ontology to data model mapping was defined. The whole process is empirically verified and confirmed. For this purpose it has been developed a software tool for ontology and data model transformation to predicate logic form and then to a set of Prolog-like clauses. After integration of these sets of clauses and rules, a Prolog-system was used for reasoning in order to quantitatively express the quality of data model with appropriate metric

Estabilização de uma linha de produção numa empresa de argamassas industriais

O projeto desenvolvido na Saint-Gobain Weber Portugal, S.A. teve como objetivo alcançar a estabilidade numa linha de produção de pastas. Para tal, trabalhou-se em três vertentes: melhoria do layout da linha na etapa da dosificação, diminuição de tempos de set-up na etapa do acondicionamento - e criação de uma base de dados capaz de armazenar os registos de produção da linha e fornecer dados para o cálculo de indicadores relevantes para apoio à sua gestão. A empresa onde este trabalho foi desenvolvido é guiada pelo World Class Manufacturing (WCM) e, como tal, todos os projetos desenvolvidos utilizam metodologias WCM e Lean Thinking, com o propósito de tentar alcançar a perfeição. A mudança de layout foi realizada em simultâneo com a aplicação da ferramenta 5S, com o propósito de melhorar o nível de organização e eliminar desperdícios. Os resultados desta intervenção permitiram reduzir em 46 km por ano a distância percorrida durante a dosificação pelos operadores, o que se traduz em 12 horas de poupança em movimentações. Para a redução do tempo de set-up foi utilizada a ferramenta SMED - Single Minute Exchange of Die, o que permitiu diminuir a complexidade nos set-ups, a criação de um procedimento padrão para os mesmo e, consequentemente, uma redução de cerca de 30% no tempo gasto anualmente com set-ups e de 18,75% no tempo gasto com o start-up. Para permitir o seguimento da dosificação e do acondicionamento, criou-se uma base de dados que permite armazenar os registos realizados pelos operadores e, posteriormente, extraí-los para o cálculo de indicadores. A análise dos indicadores produzidos permite, depois, identificar problemas, estudar as suas causas e definir ações corretivas, possibilitando, desta forma, manter a estabilidade da linha.The goal of the project developed at Saint-Gobain Weber Portugal S.A., was the achievement of stability in a paste production line. To that end, three aspects were worked out: layout enhancing in the dosage stage, set-up times reduction in the filling stage and the conception of a database capable of sustaining the data from the line and to provide it lately to calculate relevant indicators to the management of the line. The company where this work was developed is guided by World Class Manufacturing (WCM) so, every project carried out there uses WCM and Lean Thinking methodologies, with the purpose of achieving perfection. The change of layout was conducted simultaneously with the application of the 5S tool, as a way of improving the level of organization and eliminate wastes. The results of this intervention allowed the operators a reduction of 46% in the distance covered during dosage, which traduces itself in savings of 12 hours in movement. To reduce set-up times the tool SMED - Single Minute Exchange of Die was used, which allowed a reduction of complexity in the set-ups, the creation of standard procedures and an annual reduction of about 30% in set-up times and 18,75% in start-up times. To follow the dosage and the filling, a database was developed, which enables the storage of the records made by the operators and later their extraction to calculate indicators. The indicators analysis’ allows the identification of problems, the rout cause analysis as well the definition of corrective actions, enabling, that way, the wet line’s stability.Mestrado em Engenharia e Gestão Industria

An Experimental Comparison of ER and UML Class Diagrams for Data Modelling

We present the results of three sets of controlled experiments aimed at analysing whether UML class diagrams are more comprehensible than ER diagrams during data models maintenance. In particular, we considered the support given by the two notations in the comprehension and interpretation of data models, comprehension of the change to perform to meet a change request, and detection of defects contained in a data model. The experiments involved university students with different levels of ability and experience. The results demonstrate that using UML class diagrams subjects achieved better comprehension levels. With regard to the support given by the two notations during maintenance activities the results demonstrate that the two notations give the same support, while in general UML class diagrams provide a better support with respect to ER diagrams during verification activities

Architecture design in global and model-centric software development

This doctoral dissertation describes a series of empirical investigations into representation, dissemination and coordination of software architecture design in the context of global software development. A particular focus is placed on model-centric and model-driven software development.LEI Universiteit LeidenAlgorithms and the Foundations of Software technolog