Stability prediction of the software requirements specification

Complex decision-making is a prominent aspect of Requirements Engineering. This work presents the Bayesian network Requisites that predicts whether the requirements specification documents have to be revised. We show how to validate Requisites by means of metrics obtained from a large complex software project. Besides, this Bayesian network has been integrated into a software tool by defining a communication interface inside a multilayer architecture to add this a new decision making functionality. It provides requirements engineers a way of exploring the software requirement specification by combining requirement metrics and the probability values estimated by the Bayesian network

Assisted Requirements Selection by Clustering

Requirements selection is a decision-making process that enables project managers to focus on the deliverables that add most value to the project outcome. This task is performed to define which features or requirements will be developed in the next release. It is a complex multi-criteria decision process that has been focused by many research works because a balance between business profits and investment is needed. The spectrum of prioritization techniques spans from simple and qualitative to elaborated analytic prioritization approaches that fall into the category of optimization algorithms. This work studies the combination of the qualitative MoSCoW method and cluster analysis for requirements selection. The feasibility of our methodology has been tested on three case studies (with 20, 50 and 100 requirements). In each of them, the requirements have been clustered, then the clustering configurations found have been evaluated using internal validation measures for the compactness, connectivity and separability of the clusters. The experimental results show the validity of clustering strategies for the identification of the core set of requirements for the software product, being the number of categories proposed by MoSCoW a good starting point in requirements prioritization and negotiation

Light neutrino propagation in matter without heavy neutrino decoupling

We review the propagation of light neutrinos in matter assuming that their mixing with heavy neutrinos is close to present experimental limits. The phenomenological implications of the non-unitarity of the light neutrino mixing matrix for neutrino oscillations are discussed. In particular we show that the resonance effect in neutrino propagation in matter persists, but for slightly modified values of the parameters and with the maximum reduced by a small amount proportional to the mixing between light and heavy neutrinos squared.The work was supported in part by the Polish State Committee for Scientific Research (KBN) under Grant 2P03B05418, MCYT under contract FPA2000-1558, Junta de Andalucía group FQM101 and the European Community's Human Potential Programme under contract HPRN-CT-2000-00149 Physics at Colliders

Salience-based stakeholder selection to maintain stakeholder coverage in solving the next release problem

Context: The quantification of stakeholders plays a fundamental role in the selection of appropriate requirements, as their judgement is a significant criterion, as not all stakeholders are equally important. The original proposals modelled stakeholder importance using a weighting approach that may not capture all the dimensions of stakeholder importance. Furthermore, actual projects involve a multitude of stakeholders, making it difficult to consider and compute all their weights. These facts lead us to search for strategies to adequately assess the importance concept, reducing the elicitation effort. Objective: We propose grouping strategies as a means of reducing the number of stakeholders to manage in requirement selection while maintaining adequate stakeholder coverage (how selection meets stakeholder demands). Methods: Our approach is based on the salience of stakeholders, defined in terms of their power, legitimacy, and urgency. Diverse strategies are applied to select important stakeholder groups. We use k-means, k-medoids, and hierarchical clustering, after deciding the number of clusters based on validation indices. Results: Each technique found a different group of important stakeholders. The number of stakeholder groups suggested experimentally (3 or 4) coincides with those indicated by the literature as definitive, dominant, dependent, and dangerous for 4 groups; or critical, major, and minor for 3 groups. Either for all the stakeholders and for each important group, several requirements selection optimisation problems are solved. The tests do not find significant differences in coverage when important stakehold- ers are filtered using clustering, regardless of the technique and number of groups, with a reduction between 66.32% and 87.75% in the number of stakeholders considered. Conclusions: Applying clustering methods to data obtained from a project is useful in identifying the group of important stakeholders. The number of suggested groups matches the stakeholders’ theory, and the stakeholder coverage values are kept in the requirement selection

Los edificios de paneles más altos de España

RESUMEN Este artículo describe el proceso constructivo de un conjunto de 484 viviendas realizadas con paneles prefabricados portantes de hormigón. Dicho conjunto edi¿catorio, de 20 plantas de altura, se compone de diversos bloques que integran además, locales comerciales, o¿cinas, trasteros, 4 plantas de garaje e instalaciones comunes. El principal interés de este edi¿cio consiste en haber alcanzado veinte plantas sobre rasante y 4 más de sótano con el sistema constructivo de paneles prefabricados de hormigón INDAGSA; el cual dispone de un Documento de Idoneidad Técnica emitido por el IETcc, con el número DIT 452. Las obras de INDAGSA son conocidas por ser precisas, ordenadas y limpias; debido a estas características, se pudieron establecer visitas no sólo para doctorandos de la ETSAM, sino para estudiantes de la Cátedra de sistemas industrializados y prefabricados. A través de la descripción del sistema constructivo, podremos mostrar una perspectiva global de las posibilidades de los sistemas de paneles prefabricados de hormigón y las capacidades evolutivas de éstos