15,487 research outputs found

    Digital service analysis and design : the role of process modelling

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    Digital libraries are evolving from content-centric systems to person-centric systems. Emergent services are interactive and multidimensional, associated systems multi-tiered and distributed. A holistic perspective is essential to their effective analysis and design, for beyond technical considerations, there are complex social, economic, organisational, and ergonomic requirements and relationships to consider. Such a perspective cannot be gained without direct user involvement, yet evidence suggests that development teams may be failing to effectively engage with users, relying on requirements derived from anecdotal evidence or prior experience. In such instances, there is a risk that services might be well designed, but functionally useless. This paper highlights the role of process modelling in gaining such perspective. Process modelling challenges, approaches, and success factors are considered, discussed with reference to a recent evaluation of usability and usefulness of a UK National Health Service (NHS) digital library. Reflecting on lessons learnt, recommendations are made regarding appropriate process modelling approach and application

    An agile business process and practice meta-model

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    Business Process Management (BPM) encompasses the discovery, modelling, monitoring, analysis and improvement of business processes. Limitations of traditional BPM approaches in addressing changes in business requirements have resulted in a number of agile BPM approaches that seek to accelerate the redesign of business process models. Meta-models are a key BPM feature that reduce the ambiguity of business process models. This paper describes a meta-model supporting the agile version of the Business Process and Practice Alignment Methodology (BPPAM) for business process improvement, which captures process information from actual work practices. The ability of the meta-model to achieve business process agility is discussed and compared with other agile meta-models, based on definitions of business process flexibility and agility found in the literature. (C) 2017 The Authors. Published by Elsevier B.V

    Using graphical models and multi-attribute utility theory for probabilistic uncertainty handling in large systems, with application to nuclear emergency management

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    Although many decision-making problems involve uncertainty, uncertainty handling within large decision support systems (DSSs) is challenging. One domain where uncertainty handling is critical is emergency response management, in particular nuclear emergency response, where decision making takes place in an uncertain, dynamically changing environment. Assimilation and analysis of data can help to reduce these uncertainties, but it is critical to do this in an efficient and defensible way. After briefly introducing the structure of a typical DSS for nuclear emergencies, the paper sets up a theoretical structure that enables a formal Bayesian decision analysis to be performed for environments like this within a DSS architecture. In such probabilistic DSSs many input conditional probability distributions are provided by different sets of experts overseeing different aspects of the emergency. These probabilities are then used by the decision maker (DM) to find her optimal decision. We demonstrate in this paper that unless due care is taken in such a composite framework, coherence and rationality may be compromised in a sense made explicit below. The technology we describe here builds a framework around which Bayesian data updating can be performed in a modular way, ensuring both coherence and efficiency, and provides sufficient unambiguous information to enable the DM to discover her expected utility maximizing policy

    Performance requirements verification during software systems development

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    Requirements verification refers to the assurance that the implemented system reflects the specified requirements. Requirement verification is a process that continues through the life cycle of the software system. When the software crisis hit in 1960, a great deal of attention was placed on the verification of functional requirements, which were considered to be of crucial importance. Over the last decade, researchers have addressed the importance of integrating non-functional requirement in the verification process. An important non-functional requirement for software is performance. Performance requirement verification is known as Software Performance Evaluation. This thesis will look at performance evaluation of software systems. The performance evaluation of software systems is a hugely valuable task, especially in the early stages of a software project development. Many methods for integrating performance analysis into the software development process have been proposed. These methodologies work by utilising the software architectural models known in the software engineering field by transforming these into performance models, which can be analysed to gain the expected performance characteristics of the projected system. This thesis aims to bridge the knowledge gap between performance and software engineering domains by introducing semi-automated transformation methodologies. These are designed to be generic in order for them to be integrated into any software engineering development process. The goal of these methodologies is to provide performance related design guidance during the system development. This thesis introduces two model transformation methodologies. These are the improved state marking methodology and the UML-EQN methodology. It will also introduce the UML-JMT tool which was built to realise the UML-EQN methodology. With the help of automatic design models to performance model algorithms introduced in the UML-EQN methodology, a software engineer with basic knowledge of performance modelling paradigm can conduct a performance study on a software system design. This was proved in a qualitative study where the methodology and the tool deploying this methodology were tested by software engineers with varying levels of background, experience and from different sectors of the software development industry. The study results showed an acceptance for this methodology and the UML-JMT tool. As performance verification is a part of any software engineering methodology, we have to define frame works that would deploy performance requirements validation in the context of software engineering. Agile development paradigm was the result of changes in the overall environment of the IT and business worlds. These techniques are based on iterative development, where requirements, designs and developed programmes evolve continually. At present, the majority of literature discussing the role of requirements engineering in agile development processes seems to indicate that non-functional requirements verification is an unchartered territory. CPASA (Continuous Performance Assessment of Software Architecture) was designed to work in software projects where the performance can be affected by changes in the requirements and matches the main practices of agile modelling and development. The UML-JMT tool was designed to deploy the CPASA Performance evaluation tests

    Complexity Metrics for Systems Development Methods and Techniques

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    So many systems development methods have been introduced in the last decade that one can talk about a Âżmethodology jungleÂż. To aid the method developers and evaluators in fighting their way through this jungle, we propose a systematic approach for measuring properties of methods. We describe two sets of metrics which measure the complexity of single diagram techniques, and of complete systems development methods. The proposed metrics provide a relatively fast and simple way to analyse the descriptive capabilities of a technique or method. When accompanied with other selection criteria, the metrics can be used for estimating the relative complexity of a technique compared to others. To demonstrate the applicability of the metrics, we have applied them to 36 techniques and 11 methods

    A method for creating digital signature policies.

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    Increased political pressures towards a more efficient public sector have resulted in the increased proliferation of electronic documents and associated technologies such as Digital Signatures. Whilst Digital Signatures provide electronic document security functions, they do not confer legal meaning of a signature which captures the conditions under which a signature can be deemed to be legally valid. Whilst in the paper-world this information is often communicated implicitly, verbally or through notes within the document itself, in the electronic world a technological tool is required to communicate this meaning; one such technological aid is the Digital Signature Policy. In a transaction where the legality of a signature must be established, a Digital Signature Policy can confer the necessary contextual information that is required to make such a judgment. The Digital Signature Policy captures information such as the terms to which a signatory wishes to bind himself, the actual legal clauses and acts being invoked by the process of signing, the conditions under which a signatory's signature is deemed legally valid and other such information. As this is a relatively new technology, little literature exists on this topic. This research was conducted in an Action Research collaboration with a Spanish Public Sector organisation that sought to introduce Digital Signature Policy technology; their specific research problem was that the production of Digital Signature Policies was time consuming, resource intensive, arduous and suffered from lack of quality. The research therefore sought to develop a new and improved method for creating Digital Signature Policies. The researcher collaborated with the problem owner, as is typical of Participative Action Research. The research resulted in the development of a number of Information Systems artefacts, the development of a method for creating Digital Signature Policies and finally led to a stage where the problem owner could successfully develop the research further without the researcher's further input

    Patterns of information security postures for socio-technical systems and systems-of-systems

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    This paper describes a proposal to develop patterns of security postures for computer based socio-technical systems and systems-of-systems. Such systems typically span many organisational boundaries, integrating multiple computer systems, infrastructures and organisational processes. The paper describes the motivation for the proposed work, and our approach to the development, specification, integration and validation of security patterns for socio-technical and system-of-system scale systems
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