Validating a model-driven software architecture evaluation and improvement method: A family of experiments

Context: Software architectures should be evaluated during the early stages of software development in order to verify whether the non-functional requirements (NFRs) of the product can be fulfilled. This activity is even more crucial in software product line (SPL) development, since it is also necessary to identify whether the NFRs of a particular product can be achieved by exercising the variation mechanisms provided by the product line architecture or whether additional transformations are required. These issues have motivated us to propose QuaDAI, a method for the derivation, evaluation and improvement of software architectures in model-driven SPL development. Objective: We present in this paper the results of a family of four experiments carried out to empirically validate the evaluation and improvement strategy of QuaDAI. Method: The family of experiments was carried out by 92 participants: Computer Science Master s and undergraduate students from Spain and Italy. The goal was to compare the effectiveness, efficiency, perceived ease of use, perceived usefulness and intention to use with regard to participants using the evaluation and improvement strategy of QuaDAI as opposed to the Architecture Tradeoff Analysis Method (ATAM). Results: The main result was that the participants produced their best results when applying QuaDAI, signifying that the participants obtained architectures with better values for the NFRs faster, and that they found the method easier to use, more useful and more likely to be used. The results of the meta-analysis carried out to aggregate the results obtained in the individual experiments also confirmed these results. Conclusions: The results support the hypothesis that QuaDAI would achieve better results than ATAM in the experiments and that QuaDAI can be considered as a promising approach with which to perform architectural evaluations that occur after the product architecture derivation in model-driven SPL development processes when carried out by novice software evaluators.The authors would like to thank all the participants in the experiments for their selfless involvement in this research. This research is supported by the MULTIPLE Project (MICINN TIN2009-13838) and the ValI+D Program (ACIF/2011/235).González Huerta, J.; Insfrán Pelozo, CE.; Abrahao Gonzales, SM.; Scanniello, G. (2015). Validating a model-driven software architecture evaluation and improvement method: A family of experiments. Information and Software Technology. 57:405-429. https://doi.org/10.1016/j.infsof.2014.05.018S4054295

Transformación de modelos dirigida por atributos de calidad

González Huerta, J. (2010). Transformación de modelos dirigida por atributos de calidad. http://hdl.handle.net/10251/8627.Archivo delegad

Network anomaly detection research: a survey

Data analysis to identifying attacks/anomalies is a crucial task in anomaly detection and network anomaly detection itself is an important issue in network security. Researchers have developed methods and algorithms for the improvement of the anomaly detection system. At the same time, survey papers on anomaly detection researches are available. Nevertheless, this paper attempts to analyze futher and to provide alternative taxonomy on anomaly detection researches focusing on methods, types of anomalies, data repositories, outlier identity and the most used data type. In addition, this paper summarizes information on application network categories of the existing studies

Process Based Unification for Multi-Model Software Process Improvement

A number of differences among quality approaches exist and there can be various situations in which the usage of multiple approaches is required, e.g. to strengthen a particular process with multiple quality approaches or to reach certification of the compliance to a number of standards. First of all it has to be decided which approaches have potential for the organization. In many cases one approach does not contain enough information for process implementation. Consequently, the organization may need to use several approaches and the decision has to be made how the chosen approaches can be used simultaneously. This area is called Multi-model Software Process Improvement (MSPI). The simultaneous usage of multiple quality approaches is called the multi-model problem. In this dissertation we propose a solution for the multi-model problem which we call the Process Based Unification (PBU) framework. The PBU framework consists of the PBU concept, a PBU process and the PBU result. We call PBU concept the mapping of quality approaches to a unified process. The PBU concept is operationalized by a PBU process. The PBU result includes the resulting unified process and the mapping of quality approaches to the unified process.Comment: PhD Thesi

From general research questions to specific answers: Underspecificity as a source of uncertainty in biological conservation

P. 167-180Species distribution modelling may support ecologists in conservation decision-making. However, the applicability of management recommendations depends on the uncertainty associated to the modelling process. A key source of uncertainty is the underspecificity of the research question. Modelling specific questions is straightforward since they drive clearly the methodological choices about input data and model building. Nevertheless, when the research questions remain underspecific, modellers must choose among a wide spectrum of choices, with each decision sequence driving to a different outcome that explain partially the target question. We show how the underspecificity associated to a general research question about Great Bustard breeding success at geographic scale drives to multiple decision choices, leads to a variety of model outcomes and hampers the identification of specific conservation actions. We ran generalised linear models using multi-model inference on a set of databases built according to specific sequences of methodological choices. Then, we evaluated variations in model performance, complexity (parsimony) and nature of predictors, as well as averaged model predictions and spatial congruence among model outputs. Deviance and parsimony varied widely (11.46% to 83.33% and 7 to 18, respectively), as did model averaged mean predictions in occupied areas, contributing predictors and spatial congruence among outputs (rPearson = 0.44 ± 0.23 for models calibrated in occupied areas; 0.48 ± 0.06 for models calibrated in potential/accessible areas). We recommend to carefully fix research questions and associated methodological options through collaborative working frameworks to conceptualize modelling approaches and, thus, to mitigate problems arising from underspecificity and other forms of uncertainty in conservation applications.S

Methodological approaches for software process improvement in multi-model environments

Programa de Doutoramento em Informática das Universidades do Minho, de Aveiro e do PortoSoftware has improved quality of life dramatically and has now a vital role in today’s society, supporting simple services that range from simple electronic shopping to software responsible for flying planes or performing remote medical surgery. The demand on services is increasing and the result are systems of software that grow in size and complexity. For that reason these software systems are more prone to faults and software quality is an increasing concern for organisations developing software. The costs associated to lack of quality can simply put a software organisation out of business and worst, result in loss of human life. The need to ensure high levels of software quality motivates organisations to adopt approaches to improve their software development process, also referred to software improvement models or simply improvement models. There are two paradigms to process improvement, the benchmark and the analytical based process improvement approaches. Benchmark based approaches are prescriptive in nature, defining requirements or prescribing a set of practices originating from top performing organisations, that are adopted by organisations aiming to improve their software process. Analytical approaches are based on strategies that aim first, to define business, process and product goals and then establish a clear understating of the impact of process performance in these goals. A recent trend in software process improvement in the adoption of more than one improvement model into a single organisational environment, originating what are denominated multi-model environments. The goal is to attain the cumulative added benefit of adopted models. Several challenges arise in these multi-model environments that motivate the research work of this dissertation. One challenge in multi-model environments is the comparison of improvement models for selection and integration purposes and existing approaches compare models in qualitative terms. We propose metrics of size and complexity to compare improvement models in quantitative terms. Additionally, in multi-model environments, ensuring compliance to model adopted is often expected and desired. We develop a model to manage compliance of organisational practices with multiple improvement models minimising the effort required for establishing compliance in these environments. In cooperation with CRITICAL Software S.A. a process improvement process is proposed alighted with the analytical paradigm to process improvement and a set of CMMI-Dev level 5 specific goals. Finally we also addressed the issue of modelling complex system of processes that result from adopting multiple improvement models. The main research method guiding this dissertation was Design Research. We followed the steps in the method in different extents. For validation purposes the method expects demonstration and experimental validation. We focussed mainly on demonstration and we lack the desired level of experimentation. Nonetheless we provide detailed demonstrations of proposed solutions. These were submitted and accepted in peer reviewed international conferences. The main contribution of this dissertation is the demonstration, through practical scenarios, of a set to meteorological approaches to addresses challenges on conducting software process improvement in multi-model environments.O Software melhorou a qualidade de vida de uma forma considerável e assume agora um papel vital no suporte a simples serviços como pagamentos eletrónicos a software que é responsável pelo voo em aviões e por possibilitar cirurgia médica remota. A procura por novos serviços baseados em software está a aumentar e a diversificar-se. O resultado prático é que os sistemas de software estão a aumentar em tamanho e em complexidade. Por esta razão, estes sistemas incorrem num maior risco de exibir falhas e a qualidade do Software é uma procuração crescente nas organizações que desenvolvem software. Falta de qualidade pode simplesmente levar uma empresa à falência ou no pior cenário, resultar em perda de vidas humanas. A necessidade de assegurar elevados níveis de qualidade no software motiva as organizações a adotar abordagens para melhoria do processo de desenvolvimento de software, também referidas como modelos de melhoria do software ou simplesmente modelos de qualidade. Existem dois paradigmas na melhoria do processo de desenvolvimento de software, uma primeira abordagem baseada em práticas de referência e uma segunda abordagem de base analítica. As abordagens baseadas em práticas de referência assumem um carácter prescritivo definindo um conjunto de requisitos ou práticas, originárias de organizações com processos de desenvolvimento com elevados níveis de desempenho. Os modelos resultantes são adotados pelas organizações que procuram idênticos níveis de desempenho. As abordagens analíticas são alicerçadas em estratégias que visam numa primeira fase definir objetivos de negócio, de processo e de produto e depois perceber, de uma forma clara o impacto das fraquezas da organização na capacidade de esta atingir os objetivos identificados. Uma vaga recente no domínio da melhoria do processo de software é a adoção de mais do que um modelo de melhoria pela mesma organização, originando os denominados ambientes de melhoria multi-modelo. O objetivo é acumular os benefícios dos modelos adotados. Novos desafios emergem nestes ambientes que motivam o esforço de investigação desta dissertação. Um desafio nestes ambientes ´e a comparação de modelos de qualidade para efeitos de seleção e integração. As abordagens existentes permitem comparar os modelos de uma forma qualitativa. No ˆâmbito desta dissertação um dos contributos ´e uma pro posta de métricas de tamanho e de complexidade de forma a permitir uma comparação de base quantitativa. De igual forma, nos ambientes multi-modelo, assegurar o alinhamento das práticas organizacionais com os modelos adotados ´e na maior parte das vezes um requisito. No âmbito desta dissertação propomos um modelo que permite gerir a informação sobres as práticas organizacionais implementadas e os requisitos/práticas prescritas pelos modelos de melhoria adotados com o objetivo de minimizar o esforço necessário para assegurar o alinhamento de práticas organizacionais e os modelos adotados. Adicionalmente e em parceria com a empresa CRITICAL Software S.A., é proposto um processo para a melhoria do processo de desenvolvimento de software alinhado com a abordagem analítica de melhoria de processos e com os objetivos específicos da área de processo de nível 5 do CMMI-Dev. Finalmente, abordamos o problema de modelação de processos de software de elevada complexidade que resultam tipicamente da adoção de vários modelos de qualidade. É proposta uma abordagem de modelação de processos a níveis elevados de abstração que permite o seu refinamento para modelos de mais baixo nível, baseado num conjunto de regras de transição que permite a sua conversão de uma forma sistemática. A metodologia de investigação adotada nesta dissertação foi Design Research e executámos os passos expectáveis da metodologia na extensão possível. No objetivo de validação, o método espera o uso de demonstrações e de experimentação. O nosso principal foco foi a demonstração, não tendo sido possível atingir o nível de experimentação desejável. Porém, o detalhe e extensão das descrições nas demonstrações é elevado e o trabalho foi submetido e aceite em conferências internacionais da área. A contribuição desta dissertação é a demonstração, através de cenários práticos, de um conjunto de abordagens para endereçar desafios emergentes nas organizações que adotam múltiplos modelos de qualidade na melhoria do processo de software

Wearable Computing for Defence Automation : Opportunities and Challenges in 5G Network

Peer reviewedPublisher PD

Evolutionary history biases inferences of ecology and environment from δ¹³C but not δ¹⁸O values

The effects of biological similarity on geochemical signals recorded in planktonic foraminiferal tests used in paleo-reconstructions remains unclear. Here, the authors embed species-specific vital effect offsets in evolutionary models and show how shared evolutionary history shapes δ13C, but not δ18O values

Considerations for a design and operations knowledge support system for Space Station Freedom

Engineering and operations of modern engineered systems depend critically upon detailed design and operations knowledge that is accurate and authoritative. A design and operations knowledge support system (DOKSS) is a modern computer-based information system providing knowledge about the creation, evolution, and growth of an engineered system. The purpose of a DOKSS is to provide convenient and effective access to this multifaceted information. The complexity of Space Station Freedom's (SSF's) systems, elements, interfaces, and organizations makes convenient access to design knowledge especially important, when compared to simpler systems. The life cycle length, being 30 or more years, adds a new dimension to space operations, maintenance, and evolution. Provided here is a review and discussion of design knowledge support systems to be delivered and operated as a critical part of the engineered system. A concept of a DOKSS for Space Station Freedom (SSF) is presented. This is followed by a detailed discussion of a DOKSS for the Lyndon B. Johnson Space Center and Work Package-2 portions of SSF