Compliance flow: an intelligent workflow management system to support engineering processes

This work is about extending the scope of current workflow management systems to support engineering processes. On the one hand engineering processes are relatively dynamic, and on the other their specification and performance are constrained by industry standards and guidelines for the sake of product acceptability, such as IEC 61508 for safety and ISO 9001 for quality. A number of technologies have been proposed to increase the adaptability of current workflow systems to deal with dynamic situations. A primary concern is how to support open-ended processes that cannot be completely specified in detail prior to their execution. A survey of adaptive workflow systems is given and the enabling technologies are discussed. Engineering processes are studied and their characteristics are identified and discussed. Current workflow systems have been successfully used in managing "administrative" processes for some time, but they lack the flexibility to support dynamic, unpredictable, collaborative, and highly interdependent engineering processes. [Continues.

A conceptual design methodology for evaluation of alternate propulsion system modifications on small aircraft

Conceptual design is often considered to be the most important step in the design of a new product or the modification of an existing product. The important steps in this conceptual design phase is the synthesis of potential solutions into concepts, the evaluation of these concepts within a repeatable and robust design methodology framework and analysis to identify and characterise the preferred solution concept. This research has arisen from problems associated with developing aircraft-based design modification concepts and predicting the impact of these changes as they propagate or flow down through the various aircraft subsystems, impacting engineering design, and leading to certification and operations challenges. This research problem is particularly evident in highly integrated systems such as high-performance military aircraft, helicopters, and complex civil aircraft. To illustrate this methodology the author has selected two case studies which apply two different alternate propulsion system technologies to small aircraft. These case studies were selected to provide a diverse design modification space encompassing differing aircraft roles and mission types, differing technologies and subsystems integration scope, and different data sources collection and analysis methods. In order to combine the elements of design synthesis, evaluation of concept alternatives and analysis of outputs, this thesis has formulated a matrix-based conceptual design methodology. This methodology extends current knowledge by implementing the concepts of design synthesis, evaluation and analysis as an iterative process, and building and linking together existing techniques. This new methodology combined various techniques and methods such as Quality Function Deployment (QFD), quantified morphological matrices (QMM), Pugh’s decision matrices, change options Multiple-Domain Matrices (MDM), and has adapted the Change Propagation Method (CPM). The second extension to current knowledge in this area was the development of Engineering and Certification Domain Mapping Matrix (DMM) techniques based on Design Structure Matrices (DSM). This extension into engineering and certification domain was undertaken to ensure that important modification-related risks and costs were incorporated into the early stages of design. The extension adopted existing DSM and DMM-based techniques and tools to evaluate the impact of changes to subsystems and hence impact of risks and costs resulting from aircraft modifications using change propagation method analysis techniques. The validation of this conceptual design methodology was achieved by verifying and assessing the adequacy of its application through an analysis process which examined (1) coverage of the design space attributes; (2) validation of the methodology against accepted scientific and industry conceptual design frameworks; and (3) confirmation of the existing techniques, structures and tools applied within the methodology

A formal verification approach of conversations in compostie Web services

Web service composition is nowadays a very focused-on topic of research by academic and industrial research groups. This thesis discusses the design and verification of behaviors of composite web services. To model composite web services, two behaviors are proposed, namely control and operational. The operational behavior shows the business logic of the process functionality for a composite web service. The control behavior shows the constraints that the operational behavior should satisfy and specifies the states that this behavior should be in. The idea behind this separation is to promote the design, verification and reusability of web services in composite settings. To guarantee their compatibility, these two behaviors communicate and synchronize through conversation messages. State charts are used to model composite web services and symbolic model checking with NuSMV model checker is used to verify their conversations. The properties to be verified are expressed in two logics: Linear Temporal Logic (LTL) and Computation Tree Logic (CTL). A Java-based translation procedure from the design model to SMV program used by NuSMV has been developed and tested in two case studie

System modification case studies

Computation Tree Logic (CTL) model update is an approach for software verification and modification, where the minimal change principle is employed to generate admissible models that represent the corrected software design. In this paper, we apply CTL model update to models based on the well known Andrew File System protocols. We demonstrate the process of model update based on our previous theoretical results, and present a prototype implementation. Our case studies show that our model update system is sound and workable, which can be applied to different complex systems

System modification case studies

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