6,562 research outputs found
Linking component importance to optimisation of preventive maintenance policy
In reliability engineering, time on performing preventive maintenance (PM) on a component in a system may affect system availability if system operation needs stopping for PM. To avoid such an availability reduction, one may adopt the following method: if a component fails, PM is carried out on a number of the other components while the failed component is being repaired. This ensures PM does not take systemâs operating time. However, this raises a question: Which components should be selected for PM? This paper introduces an importance measure, called Component Maintenance Priority (CMP), which is used to select components for PM. The paper then compares the CMP with other importance measures and studies the properties of the CMP. Numerical examples are given to show the validity of the CMP
Organisational Memory and Innovation Across Projects: Integrated Service Provision in Engineering Design Firms
This paper provides an exploration of the dynamics of organisational remembering in firms operating through projects. The paper focuses in particular on the deliberate use of experience accumulated in the past in order to sustain innovation in the provision of services. It relies on the notions of boundary objects and brokers to empirically explore how a common memory crossing occupational and organisational boundaries is built. In so doing, it highlights how a boundary object as memory device in a project environment operates at different levels, i.e. personal, project-specific, organisational-specific and occupational specific, and how it takes different formats to perform its roles at each level. Finally, the paper highlights the role of specific communities, beyond that of specific individuals, as boundary brokers.project development, innovation processes, organisational memory, boundary brokers
E-business and circular supply chains : increased business opportunities by IT-based customer oriented return-flow management
This paper deals with the application of IT in circular supply chains (CSCs). We consider information on the installed base critical, and present an illustrative example. Next we discuss a framework of different kinds of value contained in a return, and IT-applications useful in supporting its recovery or neutralisation in case of negative externalities. Also we show which kind of CSC is needed for which kind of return. We illustrate our work by three real life case studies.reverse logistics;supply chain management;electronic commerce;product life cycle
Importance Measure-Based Maintenance Strategy Considering Maintenance Costs
Maintenance is an important way to ensure the best performance of repairable systems. This paper considers how to reduce system maintenance cost while ensuring consistent system performance. Due to budget constraints, preventive maintenance (PM) can be done on only some of the system components. Also, different selections of components to be maintained can have markedly different effects on system performance. On the basis of the above issues, this paper proposes an importance-based maintenance priority (IBMP) model to guide the selection of PM components. Then the model is extended to find the degree of correlation between two components to be maintained and a joint importance-based maintenance priority (JIBMP) model to guide the selection of opportunistic maintenance (OM) components is proposed. Also, optimization strategies under various conditions are proposed. Finally, a case of 2H2E architecture is used to demonstrate the proposed method. The results show that generators in the 2E layout have the highest maintenance priority, which further explains the difference in the importance of each component in PM
Multi-objective model for optimizing railway infrastructure asset renewal
Trabalho inspirado num problema real da empresa Infraestruturas de Portugal, EP.A multi-objective model for managing railway infrastructure asset renewal is presented. The model aims to optimize three objectives, while respecting operational constraints: levelling investment throughout multiple years, minimizing total cost and minimizing work start postponements. Its output is an optimized intervention schedule. The model is based on a case study from a Portuguese infrastructure management company, which specified the objectives and constraints, and reflects management practice on railway infrastructure. The results show that investment levelling greatly influences the other objectives and that total cost fluctuations may range from insignificant to important, depending on the condition of the infrastructure. The results structure is argued to be general and suggests a practical methodology for analysing trade-offs and selecting a solution for implementation.info:eu-repo/semantics/publishedVersio
Opportunistic Maintenance Strategy of a Heave Compensation System for Expected Performance Degradation
In the marine industry, heave compensation systems are applied to marine equipment to compensate for the adverse effects of waves and the hydraulic system is usually used as the power system of heave compensation systems. This article introduces importance theory to the opportunistic maintenance (OM) strategy to provide guidance for the maintenance of heave compensation systems. The working principle of a semi-active heave compensation system and the specific working states of its hydraulic components are also first explained. Opportunistic maintenance is applied to the semi-active heave compensation system. Moreover, the joint integrated importance measure (JIIM) between different components at different moments is analyzed and used as the basis for the selection of components on which to perform PM, with the ultimate goal of delaying the degradation of the expected performance of the system. Finally, compared with conditional marginal reliability importance (CMRI)-based OM, the effectiveness of JIIM-based OM is verified by the Monte Carlo method
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