REVISING THE THEORY OF SOCIALLY INCLUSIVE SYSTEMS ENGINEERING SOCIAL IMPACT CONSIDERATIONS IN DISTRIBUTED ASSISTIVE SYSTEMS FOR THE LEARNING DISABLED

the relationship between humans and advanced technology can be viewed as a network of interests of technical and non-technical agents. Drawing upon instrumental realist approaches as set out in agent network theory the paper describes a project currently underway in Ireland and Bulgaria which delivers comprehensive, assistive systems for people with learning disabilities. These systems address many of the difficulties associated with current assistive technology (AT) programmes, problems typically associated with the narrow focus of AT upon technology solutions. Whilst limited, it delivers a sound ethical basis for technology-centred programmes, and new trajectories for engineering research

Requirements, design and business process reengineering as vital parts of any system development methodology

This thesis analyzes different aspects of system development life cycle, concentrating on the requirements and design stages. It describes various methodologies, methods and tools that have been developed over the years. It evaluates them and compares them against each other. Finally a conclusion is made that there is a very important stage missing in the system development life cycle, which is the Business Process Reengineering Stage

Systems Engineering Methodologies, Tacit Knowledge and Communities of Practice

In the context of technology development and systems engineering, knowledge is typically treated as a complex information structure. In this view, knowledge can be stored in highly sophisticated data systems and processed by explicitly intelligent, software-based technologies. This paper argues that the current emphasis upon knowledge as information (or even data) is based upon a form of rationalism which is inappropriate for any comprehensive treatment of knowledge in the context of human-centred systems thinking. A human-centred perspective requires us to treat knowledge in human terms. The paper sets out the particular importance of tacit knowledge in this regard. It sets out two case studies which reveal the critical importance of a careful treatment of tacit knowledge for success in two complex, technology-driven projects

Improving Requirements Generation Thoroughness in User-Centered Workshops: The Role of Prompting and Shared User Stories

The rise of stakeholder centered software development has led to organizations engaging users early in the development process to help define system requirements. To facilitate user involvement in the requirements elicitation process, companies can use Group Support Systems (GSS) to conduct requirements elicitation workshops. The effectiveness of these workshops for generating a valuable set of requirements for system developers has been previously demonstrated. However, a more representative measure of progress towards a system that will meet users’ needs-- the completeness of the requirements generated by such groups has not been explored. We explore two process design considerations for increasing the completeness of requirements generated by these users: increased sharing of user stories (individual electronic brainstorming groups vs. shared user stories electronic brainstorming groups), and the use of reflective inducement prompts (unprompted vs. prompted groups). Using the Search for Ideas in Active Memory model, we predict that prompted electronic brainstorming groups will outperform any other group, including prompted, shared user stories groups at generating a more thorough set of requirements. To test the hypotheses an experiment with 56 groups consisting of 197 users was conducted. The users were asked to generate requirements for a fictitious online textbook exchange website. All hypotheses received support. The study has implications for GSS-Supported workshop design and for future research on collaborative performance in requirements elicitation

Um estudo sobre a relevancia de boas praticas de engenharia de requisitos

Orientador: Mario Lucio CortesDissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: A engenharia de requisitos descreve atividades fundamentais no processo de produção de sistemas de software. Os requisitos são o alicerce sob o qual são implementadas as fases do desenvolvimento de software. Ao longo das fases do ciclo de vida do software, a importância de ter requisitos bem definidos e controlados é bem maior do que nas fases anteriores. Um problema nos requisitos inseridos na fase de requisitos pode introduzir outros problemas nas fases seguintes, gerando problemas no software e aumentando o retrabalho, custo, prazo e esforço do projeto de software e também aumentando a insatisfação do cliente. Vários modelos de qualidade de software e normas apresentam um conjunto de boas práticas em engenharia de requisitos que podem ser usadas pelas organizações para enfrentar esses problemas. Este trabalho examina a ocorrência dessas práticas nas normas e modelos e as correlaciona, e estuda a relevância do uso dessas boas práticas de requisitos em projetos de software reais. O estudo experimental mostrou que grande parte (de 31% a 55%) dos problemas encontrados em software são conseqüências de deficiências nos requisitos. Assim, confirma dados da literatura que mostram que as deficiências nas práticas de requisitos propagam problemas para as fases seguintes do processo de desenvolvimento, aumentando o custo e prazo de projetos de software e também são a maior causa dos problemas encontrados nos sistemas de software. O estudo experimental mostrou que há correlação entre o uso de boas práticas de requisitos e a ocorrência desses problemas de software. Entretanto, não foi possível obter uma correlação significativa entre a ocorrências de problemas e o efeito disso sobre o desempenho dos projetos de software. Embora a porcentagem de ocorrências de problemas, contabilizada em cada uma das práticas de requisitos, seja diferente, não se observou prevalência significativa na importância entre as práticas de requisitos. As boas práticas e o resultado mostrado por este estudo experimental, aliado à experiência no dia a dia de trabalho com requisitos de sistema de software, permitiram apresentar algumas recomendações que podem agregar valor na implementação das práticas definidas nos modelos e normas de qualidadeAbstract: Requirements engineering describes the fundamentais activities in software systems production processes. Requirements are the foundation under which phases of the software development are implemented. Throughout the phases of the software fife cycle, the importance of having well defined and controlled requirements is much larger than in the prior phases. A requirements problem inserted in the requirements phase can introduce other problems in the following phases, causing software problems and increasing rework, costs, schedule slippage and effort of the software project, and also reducing customer satisfaction. Several software quality models and standards present best practices in requirements engineering that can be used by organizations to address these problems. This dissertation examines the occurrence of these requirements practices in some models and quality standards, correlates them and studies the relevance of the use of these best practices in real software projects. The experimental study showed that significant part (from 31% to 55%) of problems found in software is consequence of requirement problems. This confirms literature information that indicates that the deficiencies in requirements practices propagate problems to the following phases in the development process, having adverse effect on project cost and schedule, and also are the main reason of problems found in software systems. The experimental study has showed that the use of best practices is related to software problems occurrences. However, a significant correlation between the problems occurrences and the effect of this on the performance of the software projects was not found. Although the percentages of software problems occurrences, accounted in each one of the requirements practices, are different, it was not observed significant prevalence in the importance of the requirements practices. The best practices and the results presented in this experimental study, associated to the day by day job experience with software requirements, allowed to present some recommendations that can aggregate value in the implementation of the practices defined in the models and quality standardsMestradoEngenharia de SoftwareMestre em Computaçã

Modelling global behaviour with scenarios in object-oriented analysis

The first object-oriented analysis methods focused on the specification of the classes of a system and on the static relationships between them. Dynamic relationships between classes and the functional view of the system as a whole were neglected, and no models were offered for capturing system requirements. This changed with the publication of use case driven approaches such as OOSE (1992) and Fusion (1994). Modelling global behaviour by scenarios in both requirements analysis and design has since been adopted by many object-oriented methods. Scenarios are also called use cases, system operations or business processes, and they are modelled using different notations. Some of the analysis methods that use scenarios have common characteristics, namely i) the similarity of the relationship between the entities of a data model and the scenarios of a flat scenario model with a matrix, and ii) the assumption that the externally visible behaviour of the system can be subdivided into more or less independent scenario types. In the following, we will refer to these characteristics by the term matrix approach. While in many projects the matrix approach has been used successfully, several difficulties arise when more complex systems are modelled: relationships and similarities between different scenario types cannot be expressed, the dependencies between scenario types are not modelled, only one abstraction level can be represented, and the apparently seamless transition from the analysis to the design model may result in a low quality object model with a strong bias towards data modelling. These difficulties lead us to propose an enhanced scenario modelling technique (called SEAM) which overcomes some of the weaknesses of the matrix approach. This modelling technique includes composition, aggregation, specialisation and extension hierarchies of services, and is based on the paradigm of interacting objects (which can be atomic objects, subsystems or systems) offering services. Scenario types, showing the possible interaction sequences for a specific service, can be modelled on several abstraction levels, and can describe the services of any kind of object (and thus also the global behaviour of a whole system) from both an internal and external point of view. We describe the concepts and the notation of SEAM, and we show how it can be integrated into the Fusion method. The difficulties that may arise in projects using methods based on the matrix approach are not only due to the limitations of scenario modelling techniques. A major factor is the often contradictory definition of the analysis model goals, which leads to clashes of intent. Therefore we discuss the nature of such intent clashes and analyse how the different software development methods deal with them. Finally we give an overview of the various notations and basic concepts used by different scenario modelling techniques, and we provide summaries of current, mostly objectoriented, approaches to modelling global behaviour

Distributed empirical modelling and its application to software system development

Empirical Modelling (EM) is a new appro~h for software system development (SSO) that is particularly suitable for ill-defined, open systems. By regarding a software system as a computer model, EM aims to acquire and construct the knowledge associated with the intended system by situated modelling in which the modeller interacts with the computer model through continuous observations and experiments in an open-ended manner. In this way, a software system can be constructed that takes account of its context and is adaptable to the rapidly changing environment in which the system is developed and used. This thesis develops principles and tools for distributed Empirical Modelling (OEM). It proposes a framework for OEM by drawing on two crucial theories in social science: distributed cognition and ethnomethodology. This framework integrates cognitive and social processes, allowing multiple modellers to work collaboratively to explore, expand, experience and communicate their knowledge through interaction with their networked computer models. The concept of pretend play is proposed, whereby modellers as internal observers can interact with each other by acting in the role of agents within the intended system in order to shape the agency of such agents. The author has developed a tool called dtkeden to support the proposed OEM framework. Technical issues arising from the implementation dtkeden and case-studies in its use are discussed. The popular star-type logical configuration network and the client/server· communication technique are exploited to construct the network environment of this tool. A protocol has been devised and embedded into their communication mechanism to achieve synchronisation of computer models. Four interaction modes have been implemented into dtkeden to provide modellers with different forms of interpersonal interaction. In addition, using a virtual agent concept that was initially devised to allow definitions of different contexts to co-exist in a computer model, a definitive script can be interpreted as a generic observable that can serve as a reusable definitive pattern. Like experience in everyday life, this definitive pattern can be reused by particularising and adapting it to a specific context. A comparison between generic observables and abstract data types for reuse is given. The application of the framework for OEM to requirements engineering is proposed. The requirements engineering process (REP) - currently poorly understood - is reviewed. To integrate requirements engineering with SSD, this thesis suggests reengineering the REP by taking the context into account. On the basis of OEM, a framework (called SPORE) for the REP is established to guide the process of cultivating requirements in a situated manner. Examples of the use of this framework are presented, and comparisons with other approaches to RE are made