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In order to remain competitive in the global market businesses are under ever increasing pressure to ramp up production rates whilst simultaneously improving cost effectiveness to allow continued profitable growth. This requirement is particularly challenging in high value manufacturing which is characterised by expensive product and manufacturing systems and relatively low production volume. This thesis introduces a method for the design of robust and reliable manufacturing processes through the prevention of identified potential failure modes that is based on the principles of the existing Failure Mode Avoidance framework used for automotive system design. The tools and techniques that exist in the literature are reviewed in order to understand the best practice, and subsequently a Manufacturing Failure Mode Avoidance framework is designed. This framework is demonstrated through two unique case studies conducted in a real life manufacturing environment in order to validate its appropriateness to provide robust countermeasures to failure which will allow right first time manufacture. The outcomes of the implementations are discussed, conclusions drawn and opportunities for further research are provided.

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Four different thermoviscoplastic relations, namely, the Litonski-Batra, the Johnson-Cook, the Bodner-Partom and the power law are used to model the thermoviscoplastic response of a material. Each one of these relations accounts for strain hardening, strain-rate hardening and thermal softening of the material. The material parameters in these relations are found by solving an initial-boundary-value problem corresponding to simple shearing deformations so that the computed effective stress vs. the effective plastic strain curves match closely with the experimental data of Marchand and Duffy who tested thin-walled HY-100 steel tubes in torsion. These four viscoplastic relations are used to analyze dynamic thermomechanical deformations of a prenotched plate impacted on the notched side by a cylindrical projectile made of the same material as the plate. The impact loading on the contact surface is simulated by prescribing the time history of the normal component of velocity and null tangential tractions. A plane strain state of deformation is assumed to prevail in the plate and its deformations are studied for different values of the impact speed. The in-house developed finite element code employs constant strain triangular elements, one point integration rule, and a lumped mass matrix. The Lagrangian description of motion is used to describe deformations of the plate. The coupled nonlinear partial differential equations are first reduced to coupled nonlinear ordinary differential equations (ODEs) by using the Galerkin approximation. The ODEs are integrated by using the stiff solver, LSODE, which adaptively adjusts the time step size and computes the solution within the prescribed accuracy. Results computed with the four constitutive relations are found to be qualitatively similar to each other and the general trends agree with the experimental observations in the sense that at low speed of impact, a brittle failure ensues at a point on the upper surface of the notch tip. However, at high impact speeds, a ductile failure in the form of a shear band initiates first from a point on the lower surface of the notch tip. The predicted speed at which the failure mode transitions from brittle to ductile is different for the four viscoplastic relations. Results have been computed using the Bodner-Partom law to study the effects of the notch tip radius and the presence of a circular hole ahead of the notch-tip. For sharp elliptic notch tips, it is found that there is no failure transition speed and the ductile failure always preceeded the brittle failure for the range of the impact speeds studied. For the hole located on the axis of the circular notch tip, the brittle failure always preceeded the ductile failure and it initiated at a point on the lower surface of the circular hole. / Ph. D.

With increasing competitive pressures in today‟s market, it has become critical for businesses to recognise the significance of satisfying their customers so as to ensure their economic stability. Various studies have emphasised on the need for customer focus and project satisfaction in the construction industry sector. The industry, however, has not fully embraced the practice of project satisfaction, which is grounded on meeting the needs of the customer. Though most research on project satisfaction has focussed on the client, it is essential that the satisfaction of the project delivery team and in the wider context, the stakeholders be considered. In this case, the client is the centre of gravity of the project team. In order to satisfy the project team, there are challenges in assessing their requirements. This necessitates the need to develop a unique and robust method for capturing and analysing the level of integrated project team satisfaction. In this research, the project delivery team and the stakeholders have been lumped together as an integrated project team. Therefore, integrated project team satisfaction entails recognising the client and project participants‟ requirements that guarantees project successful completion and acceptance by the team. In view of this, this research presents a framework, which has been developed to plug these needs and challenges. The framework, known as the Satisfaction Assessment Integrated Framework (SAIF) involves an integrated approach that considers the participants of a construction project as a tree structure, and each member of that tree as an intermediate or top element. Relationships and interactions of the elements, and how these affect the overall satisfaction levels of a single project, are analysed based on understanding their requirements and invoking modern satisfaction attainment theory. The framework includes a method for understanding and identifying the satisfaction attributes; multi-attribute analysis for prioritising the satisfaction attributes of the clients and project participants; fault tree analysis strategy for defining the satisfaction relationship in a particular project team; and an assessment scoring system (a combination of multi-attribute analysis, and failure mode and effects analysis methodical approach) that evaluates how much each member of the project team meets the requirements or satisfaction attributes of other participants. Hence, SAIF, a novel assessment methodology, investigates and identifies possible links and the influence of integrating the construction project team and their satisfaction attributes with the aim of improving their satisfaction levels as a team. Through the findings of this research, recommendations are made to further explore the implications of satisfying a given participant against dissatisfying the participant; and subsequently improve the satisfaction assessment process.

A roof is a critical envelope of a building. It provides protection for the building interior against various weather elements, such as snow, rain and wind. Roofs are normally composed of several components such as insulation, barriers and water proofing membrane. A roof edge is the perimetric part of a roof that serves as termination for roof components. In generic terms, a roof edge system is composed of a parapet with metal components, such as coping and cleat/clip. The edge system is typically subjected to negative pressure (suction) due to wind flow over the roof. Therefore, a roof edge is the front-line of defence against wind action. To develop testing standards and design guidelines for roof edges, a project referred as REST (Roof Edge Systems and Technologies) has been initiated in cooperation with the NSERC (Natural Sciences and Engineering Research Council). For the REST project, this thesis contributes in two folds: wind design procedure and the development of an experimental method for testing roof edge components. The present thesis analyzes the wind load calculation procedures as per the National Building Code of Canada (NBCC) and American Society of Civil Engineers (ASCE). This has been achieved by taking side-by-side cities along Canada-USA border; wind load calculations were performed to demonstrate the differences and similarities between the NBCC and ASCE. As a part of the current contribution, the existing version of the online Wind-RCI Calculator was updated from NBCC2005 to NBCC2010 provisions. Towards the experimental contribution, the current study presents a new experimental method for testing and evaluating wind uplift resistance of roof edge systems by simulating wind loads in a lab environment on full-scale mock-ups. The test apparatus had a gust simulator device to mimic wind gusting (dynamic loading). This research investigates three widely used edge systems in North America: Continuous Cleat Configuration (CCC), Discontinuous Cleat Configuration (DCC) and Anchor Clip Configuration (ACC). Preliminary data show that CCC edge system has higher resistance in comparison to DCC and ACC edge systems. The experiments also revealed the need for experimental setup enhancement. Additional investigations by using the enhanced experimental setup were performed on both CCC and DCC edge systems.

A roof is a critical envelope of a building. It provides protection for the building interior against various weather elements, such as snow, rain and wind. Roofs are normally composed of several components such as insulation, barriers and water proofing membrane. A roof edge is the perimetric part of a roof that serves as termination for roof components. In generic terms, a roof edge system is composed of a parapet with metal components, such as coping and cleat/clip. The edge system is typically subjected to negative pressure (suction) due to wind flow over the roof. Therefore, a roof edge is the front-line of defence against wind action. To develop testing standards and design guidelines for roof edges, a project referred as REST (Roof Edge Systems and Technologies) has been initiated in cooperation with the NSERC (Natural Sciences and Engineering Research Council). For the REST project, this thesis contributes in two folds: wind design procedure and the development of an experimental method for testing roof edge components. The present thesis analyzes the wind load calculation procedures as per the National Building Code of Canada (NBCC) and American Society of Civil Engineers (ASCE). This has been achieved by taking side-by-side cities along Canada-USA border; wind load calculations were performed to demonstrate the differences and similarities between the NBCC and ASCE. As a part of the current contribution, the existing version of the online Wind-RCI Calculator was updated from NBCC2005 to NBCC2010 provisions. Towards the experimental contribution, the current study presents a new experimental method for testing and evaluating wind uplift resistance of roof edge systems by simulating wind loads in a lab environment on full-scale mock-ups. The test apparatus had a gust simulator device to mimic wind gusting (dynamic loading). This research investigates three widely used edge systems in North America: Continuous Cleat Configuration (CCC), Discontinuous Cleat Configuration (DCC) and Anchor Clip Configuration (ACC). Preliminary data show that CCC edge system has higher resistance in comparison to DCC and ACC edge systems. The experiments also revealed the need for experimental setup enhancement. Additional investigations by using the enhanced experimental setup were performed on both CCC and DCC edge systems.

This research is aimed at addressing problems in the field of asset management relating to risk analysis and decision making based on data from a Supervisory Control and Data Acquisition (SCADA) system. It is apparent that determining risk likelihood in risk analysis is difficult, especially when historical information is unreliable. This relates to a problem in SCADA data analysis because of nested data. A further problem is in providing beneficial information from a SCADA system to a managerial level information system (e.g. Enterprise Resource Planning/ERP). A Hierarchical Model is developed to address the problems. The model is composed of three different Analyses: Hierarchical Analysis, Failure Mode and Effect Analysis, and Interdependence Analysis. The significant contributions from the model include: (a) a new risk analysis model, namely an Interdependence Risk Analysis Model which does not rely on the existence of historical information because it utilises Interdependence Relationships to determine the risk likelihood, (b) improvement of the SCADA data analysis problem by addressing the nested data problem through the Hierarchical Analysis, and (c) presentation of a framework to provide beneficial information from SCADA systems to ERP systems. The case study of a Water Treatment Plant is utilised for model validation.

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The railway transportation system is fundamental in sustaining the economic activities of a country, by providing a safe, reliable and relatively affordable means of transporting people and goods; hence, the need to ensure its ongoing reliability is of paramount importance. The principle and applications of rail reliability have been reviewed, and reliability improvement in rail infrastructure has been investigated using failure mode and effect analysis (FMEA). Reliability improvement is a continuous process that is geared to meeting dynamic changes in operation and stakeholders’ expectations. Recently, growth has occurred in the amount of rail transport traffic utilisation undertaken, together with the degradation of the infrastructure involved. Such deterioration has amplified the operating risks, leading to an inadequacy in rail track maintenance and inspection that should have kept abreast with the changes. The result has been increased rail failures, and subsequent derailments. A case study of the Passenger Rail Agency of South Africa (PRASA) Metrorail maintenance policy was reviewed to evaluate its maintenance strategy and identifying the potential critical failure modes, so as to be able to recommend improvement of its reliability, and, thus, its availability. On the basis of the case study of PRASA Metrorail maintenance strategy and its performance, it is recommended that PRASA Metrorail change its maintenance policy through employing a cluster maintenance strategy for each depot. / AFRIKAANSE OPSOMMING: Die spoorwegvervoerstelsel is fundamenteel om die ekonomiese bedrywighede van ’n land te ondersteun deur die voorsiening van ’n veilige, betroubare en betreklik bekostigbare manier om mense en goedere te vervoer. Dus is dit van die allergrootste belang om die voortgesette betroubaarheid daarvan te verseker. Die beginsels en toepassings van spoorbetroubaarheid is hersien en die betroubaarheidsverbetering van spoorinfrastruktuur met behulp van foutmodus-eneffekontleding (“FMEA”) ondersoek. Betroubaarheidsverbetering is ’n voortdurende proses om tred te hou met dinamiese bedryfsveranderinge sowel as verskuiwings in belanghebbendes se verwagtinge. Die hoeveelheid spoorvervoerverkeer het onlangs beduidend toegeneem, terwyl die betrokke infrastruktuur agteruitgegaan het. Dié agteruitgang het die bedryfsrisiko’s verhoog, en lei tot ontoereikende spoorweginstandhouding en -inspeksie, wat veronderstel was om met die veranderinge tred te gehou het. Dit gee aanleiding tot ’n toename in spoorwegfoute en gevolglike ontsporing. ’n Gevallestudie is van die instandhoudingsbeleid van die Passasierspooragentskap van Suid- Afrika (PRASA) Metrorail onderneem om dié organisasie se instandhoudingstrategie te beoordeel en die moontlike kritieke foutmodusse te bepaal. Die doel hiermee was om verbeteringe in stelselbetroubaarheid en dus ook stelselbeskikbaarheid voor te stel. Op grond van die gevallestudie van die PRASA Metrorail-instandhoudingstrategie en -prestasie, word daar aanbeveel dat PRASA Metrorail sy instandhoudingsbeleid verander deur ’n klusterinstandhoudingsplan vir elke depot in werking te stel.

Este trabalho apresenta um método de análise de confiabilidade de sistemas novos em desenvolvimento, no qual se utiliza como referência dados predominantemente qualitativos. O método proposto está organizado em três fases, as quais são subdivididas em etapas que constituem as atividades a serem realizadas. A primeira fase é a análise FMEA, que visa definir e identificar falhas potenciais do sistema ainda em seus estágios iniciais de conceituação e projeto. A segunda fase é a análise de confiabilidade, que tem como objetivo gerar dados quantitativos para uma análise aprimorada da confiabilidade do sistema a partir de dados qualitativos coletados na fase da análise FMEA. A terceira fase consiste na análise comparativa e visa, além de comparar os resultados obtidos previamente, propor uma forma de integração destes. O método proposto foi aplicado em dois sistemas principais de um sistema de transporte sobre trilhos: o sistema de propulsão e o sistema de controle. Com o intuito de integrar as duas técnicas, propôs-se uma nova forma de calcular o risco, denominado RPNI, que leva em consideração o índice de severidade, a probabilidade de ocorrência, a probabilidade de detecção e o índice de impacto. A partir desse valor, foi então possível determinar os componentes considerados prioritários para os sistemas e propor as medidas cabíveis, tendo em vista as metas de segurança e a confiabilidade do sistema em desenvolvimento. / This work presents a method for the reliability analysis of a new system under development, which uses qualitative data as predominant reference. The proposed method is organized in three phases, which are subdivided in activities to be accomplished. The first phase employs the FMEA to define and identify potential failures in the early stages of conceptualization and system design. The second phase contemplates a mathematical reliability analysis, providing quantitative data for an enhanced analysis of system reliability from qualitative data collected at the first phase. The third phase, named comparative analysis, compares the previous results and proposes an integrated prioritization. The proposed method was applied in two major systems of a transportation system on guideways: the propulsion and the control systems. In order to integrate the FMEA and the mathematical analysis, a different form to calculate the risk, named RPNI, was proposed, which considers the severity index, occurrence probability, detection probability and the impact index. Using the RPNI, it was possible to determine system priority components and to propose appropriate measures to increase the safety and reliability goals of the system under development.