Contribution à une méthode de conception par objets pour des logiciels ADA

The architectural design phase is the key phase to make the construction project successful and meets the owner’s requirements. The main objective of this research is to explore risks involved in the architectural design phase. Meanwhile, the study resulted in some recommendations for improving the efficiency of decision making process in architectural design phase. From five cases study, two interviews and one questionnaire, four major risks among the twenty four found risks were identified. The four major risks and their possible solution are: 1. The design team uses some kind of routine design when working on a different project. The solutions are that the design team needs to take a careful assessment on design task and to improve their knowledge on different type of project. 2. The design team doesn’t have a mutual definition and languages in conceptual design phase. The solutions are that the design team needs to build up a standard form of design and discussion carefully about the change in the very first meeting of project. 3. Orders were changed during the progress. The solution is that the Owner needs to discuss with the assignment manager or take suggestion from expert to complete design task 4. Legal documents were changed while project is on process. The solution is that the officer government needs to discuss with disciplines to get a feedback about the background or the necessity of change. This study has built a framework for managing the risks during architectural design phase on a building project. The framework could be recommend for future research and apply the framework to other design projects, such as urban planning, civil construction and so on. Moreover, it would be significant if the associated financing and construction risk could be further studied.

Metric-based Evaluation of Implemented Software Architectures

The goal of this article is to provide a rigorous conceptual framework for defining the concepts of dependability and resilience. Since the seventies, the terms dependability and resilience have been used in nearly all the scientific and technological fields related to Information and Communication systems. The introduction and use of these concepts in all these fields makes it difficult to have a common and precise definition. Having such a definition is nevertheless mandatory for the software and systems engineering research community that create development processes, languages and tools to support the engineering of products that would be required to be dependable or resilient. For this, we introduce an abstract and generic terminology defined mathematically to be used when speaking about dependability and resiliency. We also provide some abstract semantic descriptions to these terminological elements. This formal framework is defined from a software engineering perspective, which means that we define its components such that they are useful for the development or improvement of analysis, architectural design, detailed design, implementation, verification and maintenance phases. To this aim, we provide the necessary elements in accordance with a model driven engineering perspective that enable the definition of a new modelling language for dependable and resilient systems.

This paper describes the results of a project for the European Space Agency to produce guidelines for the development of real time software for onboard spacecraft applications. The project has produced guidance for the software requirements, architectural design, detailed design and implementation phases of the software development process, based on the use of HOORA and HOOD methods. A system of annotations has been devised for capturing performance and other non-functional requirements in HOORA and HOOD, such that existing method support tools are not affected by the presence of the annotations, which can be processed by additional tools. The paper outlines the guidance and the system of annotations.KeywordsArchitectural DesignReal Time RequirementRealisme ProjectSchedulability AnalysisProtected ObjectThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Using engineering performance evaluations to explore design alternatives during the conceptual phase of architectural design helps to understand the relationships between form and performance; and is crucial for developing well-performing final designs. Computer aided conceptual design has the potential to aid the design team in discovering and highlighting these relationships; especially by means of procedural and parametric geometry to support the generation of geometric design, and building performance simulation tools to support performance assessments. However, current tools and methods for computer aided conceptual design in architecture do not explicitly reveal nor allow for backtracking the relationships between performance and geometry of the design. They currently support post-engineering, rather than the early design decisions and the design exploration process. Focusing on large roofs, this research aims at developing a computational design approach to support designers in performance driven explorations. The approach is meant to facilitate the multidisciplinary integration and the learning process of the designer; and not to constrain the process in precompiled procedures or in hard engineering formulations, nor to automatize it by delegating the design creativity to computational procedures. PAS (Performance Assessment Strategies) as a method is the main output of the research. It consists of a framework including guidelines and an extensible library of procedures for parametric modelling. It is structured on three parts. Pre-PAS provides guidelines for a design strategy-definition, toward the parameterization process. Model-PAS provides guidelines, procedures and scripts for building the parametric models. Explore-PAS supports the solutions-assessment based on numeric evaluations and performance simulations, until the identification of a suitable design solution. PAS has been developed based on action research. Several case studies have focused on each step of PAS and on their interrelationships. The relations between the knowledge available in pre-PAS and the challenges of the solution space exploration in explore-PAS have been highlighted. In order to facilitate the explore-PAS phase in case of large solution spaces, the support of genetic algorithms has been investigated and the exiting method ParaGen has been further implemented. Final case studies have focused on the potentials of ParaGen to identify well performing solutions; to extract knowledge during explore-PAS; and to allow interventions of the designer as an alternative to generations driven solely by coded criteria. Both the use of PAS and its recommended future developments are addressed in the thesis.

Abstract. Through the implementation of algorithmic design, there has been a revolution in digital architecture both in architectural design and construction. By implementing algorithmic design, architects are able to integrate powerful computional instruments with creative design to play the role of programming on behalf of architect. This paper has studied configuration free forms in conceptual design by using algorithmic programs such as ‘Formian’. Formian is regarded as a computational instrument for the purpose of configuration forms, which is commonly used to geometric compositions including points, lines and surfaces. Producig configuration with parametric components can be considered as one of the main characteristics of Formian. Therefore, there can be an improvement in the formulation of configurations where a change takes place in parameter components. This program can pave the way for towers, domes and other structures to obtain a new dimension. The Formian not only is able to increase the architectural and space structure designs, but also it can conceive them. There is a paradigm shift in architecture when such a software is used, resulting in more constructive presence of architects in building constructions.

Italian historian Manfredo Tafuri develops his ‘historical project’ in architecture during the 1960’s and 1970’s in three seminal books, which reach the English speaking specialist audience with a certain delay. Histories and Theories of Architecture (1968), which prepares the ground for the redefinition of a critical and independent history of architecture is first translated in English in 1979. Architecture and Utopia (Progetto e utopia, 1973) is translated in 1976, and becomes a point of reference for architectural histories and for the definition of architectural theories, mainly in the United States. The Sphere and the Labyrinth (1980), translated in 1987, is the text which formally defines and presents the ‘historical project’. Tafuri’s dense and highly politicized prose is often subjected in the English versions to numerous simplifications and reductive interpretations. Yet, the time lag and the space between languages that these translations occupy are inhabited by polemical and fertile reactions to the texts from the world of architectural design. Symptomatic of all, Aldo Rossi’s L’architecture assassinee, a rebuke in drawing to some of Tafuri’s remarks in Architecture and Utopia that seemed to suggest -but the interpretation is arguable– the ‘death’ of architecture as project (progetto). Tafuri’s texts instigate a dialogue between architectural history and practice, particularly relevant at a time in the development of the discipline when history was being redefined in its critical role as a ‘project’ –thus appropriating the active and propositional role traditionally assigned to architectural design–, while architectural design –still coping with the legacy of Modernism and with changed production systems- often found itself relegated to the paper of exhibitions, competitions and theoretical projects. This paper explores the relationship between architectural history and design in Tafuri’s work, focusing on recent reconsideration and interpretations of his work. It argues that, beyond instrumental simplifications, Tafuri’s ‘project’ remains active and essential in architecture’s critical culture today.

The research focuses on the emerging domain of Big Data and the Internet of Things in the context of architectural design and operation. The profession of architecture relies on the use of data in almost all stages of the building cycle. However, this data is often utilised in a trivial manner, without clearly addressing how the data is utilised, when it is utilised, the value of such utilisation and the impact the data has on the design operations and the overall building. Data in architecture mainly serves as a medium of communication to generate a design. Data can only be as good as the technology available at the time it is gathered. Nevertheless, the role of data has changed with the advancement of digital data technologies such as Big Data and the Internet of Things. Digital data is now a driver for businesses and operations in other industries. The investigation of contemporary data utilisation in architecture design reveals that data is not utilised as a driver for the design in most cases and, when it is utilised as a driver, it is not exploited and is not explicitly addressed as part of the business. A knowledge gap in architecture in addressing the utilisation of data and addressing digital data as a driver in design operations is identified. This identification is supplemented by observing that data-driven operations provide the potential for better and more efficient design and business. To fill this knowledge gap and to build a foundation for data utilisation in architecture, this thesis proposes a Data-Driven Operational Framework for architecture, which is the main output of this research and its main contribution to knowledge. The Data-Driven Operational Framework reveals and explains the required components and operations for employing a data-driven design approach in architectural processes and business. In order to develop such a framework, an investigation of current architectural cases that utilise digital data was completed, which is a crucial part of the research. However, it was not possible to investigate these cases without having a thorough understanding of the state-of-the-art data technologies and an understanding of the existing taxonomy of data and the existing taxonomy of value in architectural operations. To build this taxonomy of data, a literature review investigating the terms data, digital data operations, Big Data and the Internet of Things was conducted. To build the taxonomy of value, a literature review of values, value creation and valuation methods in architecture was performed. Also, this value investigation led to the development of a Digital Value Equaliser, which is a conceptual representation that supports the analysis of values in architectural design cases. The case studies were analysed following the coding techniques of Grounded Theory Methodology. The coding procedures were followed systematically and continuously until data saturation was reached. Reaching data saturation led to the development of the Data-Driven Operational Framework for architecture. The Data-Driven Operational Framework has two theoretical applications, the Data-Driven Levels in architectural operations framework and the Data-Driven Impact on the AEC framework. These two theoretical frameworks are the findings of the second part of the research and add to the research contribution. The Data-Driven Levels framework reveals the different automation levels in utilising data in architectural operations. This framework classifies data operations in architecture into six levels according to how automated they are and the degree of human involvement in each operation. The Data-Driven Impact framework shows the anticipated impact of employing data-driven operations on the existing business and cultural models in architecture, engineering and construction (AEC). This shows the required business and cultural changes in operating an architecture business. The Impact framework supports architects to identify what measures and changes are needed to benefit from the use of data-driven operations in their practices and business.

A major cause of many complications in the field of software architectures is the lack of appropriate abstractions for separating, combining and encapsulating concerns of various kinds in architectural descriptions. Architectures of most complex software-intensive systems involve concerns that inherently crosscut the natural boundaries of the elements composing the architecture descriptions. Crosscutting concerns intersect the common modularity of systems as prescribed by their architecture descriptions, by traversing both the components and connectors, i.e., the relationships among the components. Crosscutting concerns are critical aspects of many architectural problems. However, architectural descriptions written in special-purpose languages (ADLs) like Wright, Darwin, Rapide and Acme should support descriptions of multiple structures, which include diagrams, models and views, that intentionally address different kinds of concerns. ADLs should show how various concerns affect each other in architectural designs; they should also allow one to identify, analyze and elaborate architectural concerns that cut across several software components, such as transactions, security, load balancing, synchronization, reuse, customization, scalability, etc.; they should, but they do not. This dissertation presents a new approach to software architecture that is suitable for supporting concern-oriented development and documentation of architectures for software-intensive systems. This approach allows for creating and documenting a multidimensional software structure that is referred to as concern-oriented software architecture; it provides new mechanisms for encapsulating individual concerns into independent architectural constructs. The ultimate goal of this new approach is to provide support for achieving design by concerns all through the development and description of software architectures. Moving towards this goal, we present a particular concern-oriented architectural framework called Perspectival Concern-Spaces (PCS). The PCS Framework offers a flexible and extensible means a) for supporting advanced separation of concerns in architectural design, and in the construction and evolution of software-intensive systems; and b) for filling the gap between architectural descriptions and modern software development artifacts. To show the feasibility of the proposed approach, we provide new modeling techniques that are used to describe and apply an aspect-oriented architectural pattern, called the On-demand Remodularization pattern. We give several examples of how the PCS Framework can be used to integrate concern-oriented architectural documentations with mainstream software development artifacts.

This paper focuses on requirements to design traceability. There have been many advances in requirements traceability and various tools are available to perform requirements traceability. Software Requirements to Design Traceability Technique named SoRDeTT, is the methodology proposed, which is based on templates. Software Requirements Specification (SRS) and Software Design Document (SDD) form inputs to this methodology. SoRDeTT has defined a common template (for requirement and design) to capture data and information from these documents. The template with data populated from SRS is called SRS Trace Item (SRSTI), and the one filled with data from SDD is called SDD Trace Item (SDDTI). The template defined needs to be filled for every software requirement. Initialization, input, output, data type, range, resolution of data etc. are the fields which are part of the template. The filled templates namely SRSTI and SDDTI corresponding to all software requirements are used to carry out traceability analysis. Since the template is same for requirements and design data, hence it is easy to compare and raise alerts for appropriate action to be taken.

A software process improvement programme is under way at a Spanish financial institution. A structured methodology, supported by formal and informal techniques and tools, is being established by a methodological support group, as a starting point for the improvement. This paper centres particularly on the methodological and automated management of software requirements analysis. This process was previously performed in a not formal manner, and the most direct consequence was the high costs in maintenance. The methodology developed includes actions to obtain, refine and validate the software requirements. It also includes an organisational Software Requirements Specification (SRS) standard, implemented on a commercial tool which was selected as a result of a formal evaluation process. Additionally, a procedure was defined for working with the SRS and the tool. The results of this practical experience show an improvement in SRS quality, and work is no longer duplicated, since more correct and complete specifications are obtained.

Self-organisation is increasingly being regarded as an effective approach to tackle modern systems complexity. The self-organisation approach allows the development of systems exhibiting complex dynamics and adapting to environmental perturbations without requiring a complete knowledge of the future surrounding conditions. However, the development of self-organising systems (SOS) is driven by different principles with respect to traditional software engineering. For instance, engineers typically design systems combining smaller elements where the composition rules depend on the reference paradigm, but typically produce predictable results. Conversely, SOS display non-linear dynamics, which can hardly be captured by deterministic models, and, although robust with respect to external perturbations, are quite sensitive to changes on inner working parameters. In this thesis, we describe methodological aspects concerning the early-design stage of SOS built relying on the Multiagent paradigm: in particular, we refer to the A&A metamodel, where MAS are composed by agents and artefacts, i.e. environmental resources. Then, we describe an architectural pattern that has been extracted from a recurrent solution in designing self-organising systems: this pattern is based on a MAS environment formed by artefacts, modelling non-proactive resources, and environmental agents acting on artefacts so as to enable self-organising mechanisms. In this context, we propose a scientific approach for the early design stage of the engineering of self-organising systems: the process is an iterative one and each cycle is articulated in four stages, modelling, simulation, formal verification, and tuning. During the modelling phase we mainly rely on the existence of a self-organising strategy observed in Nature and, hopefully encoded as a design pattern. Simulations of an abstract system model are used to drive design choices until the required quality properties are obtained, thus providing guarantees that the subsequent design steps would lead to a correct implementation. However, system analysis exclusively based on simulation results does not provide sound guarantees for the engineering of complex systems: to this purpose, we envision the application of formal verification techniques, specifically model checking, in order to exactly characterise the system behaviours. During the tuning stage parameters are tweaked in order to meet the target global dynamics and feasibility constraints. In order to evaluate the methodology, we analysed several systems: in this thesis, we only describe three of them, i.e. the most representative ones for each of the three years of PhD course. We analyse each case study using the presented method, and describe the exploited formal tools and techniques.

Requirements Engineering is the set of activities involved in creation, managing, documenting, and maintaining a requirements’ set for a product. Engineering involves the use of systematic repeatability techniques to ensure that the Software Requirements are complete, consistent, valid, and verifiable. Software Requirements Specification is an organized process oriented toward defining, documenting and maintaining requirements throughout the development life cycle. Many authors suggest that requirements should always focus their claims on what the software product needs to address, without specifying how to implement them. However, the detail of Software Requirements is influenced by several factors such as: organizational thinking; existing specification standards; and regulatory needs. This work fits exactly with regulatory needs, where the characteristics of Software Requirements Specification in Regulated Environments such as aeronautics, railways and medical are presented and explored. This paper presents and analysis of software requirements specification characteristics in regulated environments. The four characteristics identified are: consistency (internal and external), unambiguity, verifiability, and traceability. The paper also describes the three standards used in these regulated environments (RTCA DO-178C, IEC 62279 and IEC 62304) and examines their similarities and differences from a Requirements Specification standpoint. The similarities and differences will be used to address a future requirements framework universal process that can be configured to address each standard by the usage of Software Process Lines.

Software requirements analysis is crucial for any software project and it is the basis of requirements reuse within Software Product Line engineering. Software requirements specifications are usually expressed in natural language, which are informal, imprecise and ambiguous, thus analyzing them automatically is a challenging task. Although methods towards automatic analysis of software requirements have been studied before, many of them have limitations and effective researches in this area are still lacking. Therefore, in this paper a new approach was proposed to automatically extract structured information of functional requirements from Software Requirements Specifications in natural language. The methods of machine learning, natural language processing and semantic analysis were employed and combined in this approach. With a 10-fold cross validation setting, the method was evaluated on a manually annotated corpus. The experiments show that this approach achieves a good performance. Moreover, it was found that the model trained on the requirements dataset of the E-commerce systems, can be used to extract semantic information from the requirements of auto-maker systems. The cross-domain extraction results show that the method of this paper is domain independent and robust to some extent.

Limited fossil energy resources and the potential danger of nuclear power plants led to growing popularity of solar energy. In Switzerland, Building Integrated Photovoltaic (BIPV) is expected to be responsible for up to quarter of the energy production from renewable resources by the time of 2035. In order to protect the existing natural landscape, BIPV must be concentrated in urban spaces, which means that certain amount of existing building envelopes have to be turned into energy generators. There is a growing concern about BIPV retrofits because they may change the visual appearance of the existing city images to a large extend and/or in a negative way. In order to manage the potential visual impact resulting from BIPV expansion in urban spaces, evaluation methods should be able to measure it appropriately. Existing evaluation methods show insufficiencies for this purpose: either they cannot guarantee objectivity and continuity of evaluation standards throughout assessments of different BIPV projects, because their qualitative criteria are vulnerable to subjective preferences; or they only use formal design parameters to evaluate the visual integration quality of BIPV and therefore lack neuroscientific base. In order to tackle these insufficiencies, an objective evaluation method is proposed that is capable of measuring the BIPV visual impact in building retrofits in a quantified approach based on neuroscience knowledge. The assessment should be made in concept phase of the project, so as to identify the BIPV designs that have the least negative visual impact. The proposed evaluation method integrates saliency model, which imitates the mechanism of human visual attention, into assessment procedures. First, the probability of a BIPV installation attracting human visual attention in the respective visual scene is calculated quantitatively with the saliency model. Then the modifications of saliency values in this very visual scene before and after the BIPV retrofit are assessed. In the end, the modifications of saliency values are transformed into BIPV visual impact and objectively expressed as single values. The analyses are based on renderings generated from RADIANCE and programming in MATLAB. This method is demonstrated with a small case study that simultaneously serves as proof-of-concept. The proposed evaluation method is applied on a realistic case study: BIPV designs for a church roof. In total, 5 designs were developed with variations in BIPV installation location, roof coverage percentage, module size, PV material und design approach. The lowest visual impact value was induced by the BIPV design with the most careful and considerate integration approach, the design with the boldest integration approach obtained the highest visual impact value. The evaluation method proved to be feasible to a large extend. It is believed that the synergy between architecture and neuroscience can contribute to a growing understanding of human responses to the built environment. Hopefully the findings from this thesis can help in minimizing the negative visual impact induced by BIPV expansion in urban spaces, and also aid architects in gaining new understandings for visual aspects in architecture design.