•This study is the first systematic review concerning maintenance in Industry 4.0.•The impact of each Industry 4.0 technology in maintenance tasks has been identified.•Remote Maintenance had an ...increase due to Augmented Reality and smart devices.•The results show Self-maintenance is an attractive possibility for smart factories.•Smart factories require changes in manufacturing and operators management.
Industry 4.0 is revolutionizing manufacturing, increasing flexibility, mass customization, quality and productivity. In today's competitive manufacturing scenario, maintenance is one of the most critical issues and companies are approaching its digital transformation from technological and management perspectives.
This article carries out a systematic literature review aimed to investigate how maintenance tasks and maintenance management strategies are changing in Industry 4.0 context, analyzing the state-of-the-art of Industry 4.0 technologies currently employed in maintenance and the resulting potential innovations in maintenance policies and manufacturing management. In addition, the most relevant trends in current maintenance policies have been investigated, such as “remote maintenance” and the attractive possibility of a “self-maintenance”. Also, the importance of human factor has been considered. The results are summarized in a comprehensive database, to provide, through concepts and empirical evidence present in literature, examples and strategies for the implementation of maintenance in Industry 4.0.
Various stormwater best management practices and green infrastructures (GIs) are recommended to address flooding, stormwater runoff, water quality, and sustainability. While detention basins are ...considered one of the main GI strategies, their benefits cannot be fully realized without properly maintaining them and making sure that they stay operational. Therefore, this paper used agent-based modeling (ABM) to devise an optimal maintenance program for detention basins to ensure that they function properly and continue to perform their water quality and flood control functions. More specifically, the following 2 agent types were incorporated in the model: 1) the detention basins were considered as static agents, and 2) the service teams responsible for the operation (maintenance, repair, and replacement) of the detention basins were considered as active agents. The developed ABM was applied for the entire network of stormwater detention basins in Newark, NJ. Sensitivity analysis was conducted to identify the most critical variables affecting the total cost of operating the network of detention basins as well as the functioning percentage of detention basins. In addition, optimization was implemented to determine the best maintenance program or policy that minimizes the total cost of operations, while also making sure that a desired functionality level or threshold is achieved for the entire network of detention basins. Finally, the ABM was statistically validated using a total of 10,000 Monte Carlo runs and 99% confidence intervals. The optimization results showed that, in order to minimize the total cost of maintaining the entire network of detention basins and ensure that at least 80% of the basins are in a functioning state at the end of the planning horizon, the decision-maker should implement the following maintenance program or strategy: have 2 service teams for the operations of the detention basins, follow a replacement policy, and replace detention basins after 3 maintenance periods. Also, the identified optimal maintenance program or strategy would result with an average total annual cost of around $4,085,000, where the average annual repair cost is around $2,572,200, the average annual maintenance cost is around $19,700, the average annual replacement cost is around $763,100, and the average annual service team cost is around $730,000. The proposed ABM for detention basins can be extended to other GIs as well as to different geographical areas. The usage of ABM has the advantage to reduce the subjectivity in developing plans for managing GIs.
•Agent-based modeling could be implemented for deciding optimal maintenance strategies for a network of detention basins.•The optimal maintenance strategy was based on minimizing total cost and ensuring at least 80% of the basins are functional.•The identified best maintenance program leads to an average total annual cost of around $4,085,000.•The determined optimal maintenance strategy was statistically validated using Monte Carlo runs and 99% confidence intervals.•Using agent-based modeling has the advantage of reducing the subjectivity in developing plans for managing detention basins.
The growth of global competition has led to significant changes in the way manufacturing companies operate. These changes have affected maintenance and made its role even more important for business ...success. To remain competitive, manufacturing companies must constantly improve the efficiency of their production processes. The fact that maintenance is becoming increasingly important for the industrial sector is evident from the ongoing discussions on national industrialization programs. At the same time, despite the growing demand for reliable production equipment, some manufacturers are engaged in the development of strategic services. Moreover, traditional maintenance strategies, such as reactive maintenance, are no longer sufficient to meet industrial needs, such as maximizing the reduction in failures and fatigue of production systems. This article presents an analysis of maintenance strategies. The review aims to point out the importance of unplanned downtime that may occur during the operation of the equipment at the production plant. To maintain the working condition of the machine, various maintenance strategies have been developed, among which the most popular are reactive maintenance, planned maintenance and condition-based maintenance. The predicted condition method is more effective for the maintenance of complex and responsible machines, but planned maintenance remains the most common maintenance program.
This article tackles how to select an adequate maintenance strategy for public buildings by using novel multi-criteria decision-making (MCDM) models to validate their appropriateness for sustainable ...practices. The new innovation is the unique advantage of fuzzy axiomatic design (FAD) to consider the design requirements for public buildings. The stepwise weight assessment ratio analysis (SWARA), weighted additive sum product assessment (WASPAS), fuzzy axiomatic design (FAD) and the additive ratio assessment (ARAS) are competently integrated. Questionnaire data from a public building was used to evaluate and order the criteria in the rehabilitation exercise. The principal results are: For environmental and social criteria, the most and least suitable maintenance strategies are condition-based (S3) and preventive maintenance (S1) strategies, respectively. The most and least suitable maintenance strategies are corrective maintenance (S4) and S1 (ARAS), S4 and S1 (FAD), S1 and S3 (weighted additive method), respectively. Based on the aggregated criteria and the solution methods, the most suitable order for the case study maintenance strategies is S2>S1>S3>S4. This study shifts attention to MCDM from the old literature perspectives of risks and life-cycle methods in the strategic choice of maintenance for public buildings.
•Building rehabilitation rules ensure compliance with code requirements.•Paper builds up a quantitative instrument for sustainable rehabilitation strategy.•Public building issues are solved through questionnaire administration data.•Instrument potentials established by data from a building materials public building.
The ever increasing size of wind turbines and the move to build them offshore have accelerated the need for optimised maintenance strategies in order to reduce operating costs. Predictive maintenance ...requires detailed information on the condition of turbines. Due to the high costs of dedicated condition monitoring systems based on mainly vibration measurements, the use of data from the turbine supervisory control and data acquisition (SCADA) system is appealing. This review discusses recent research using SCADA data for failure detection and condition monitoring (CM), focussing on approaches which have already proved their ability to detect anomalies in data from real turbines. Approaches are categorised as (i) trending, (ii) clustering, (iii) normal behaviour modelling, (iv) damage modelling and (v) assessment of alarms and expert systems. Potential for future research on the use of SCADA data for advanced turbine CM is discussed.
•The RAMS-based comprehensive evaluation method is used to comprehensive evaluate high-speed EMU components.•Reliability evaluation method based on the Weibull proportional hazard model.•WPHM-based ...EMU component availability model can be used to quantitatively calculate the variation of the availability with the mileage and provide an availability evaluation curve within a certain period.•A whitened weight-based EMU component maintainability clustering evaluation model was built. The entropy weight method was used to determine the estimates of the gearbox indexes.•A gray correlation evaluation model reflecting the relationship between the component and its ideal safe state was built and a component safety classification was performed.
EMU (Electric Multiple Units) components were evaluated in multiple dimensions, i.e. reliability, availability, maintainability, and safety. A parameter estimation method, which is based on the data on the mileage between failures and quantities monitored in the actual operation, was put forward for the Weibull proportional hazard model to determine their operational reliability. A multi-index component maintainability evaluation model, which is based on empirical distribution functions, and a maintainability cluster evaluation model, which is based on whitened weight functions, were built, and the entropy weight method was introduced to determine the estimates of the indexes. A component safety evaluation method, which has the safety risk factor as its evaluation basis, was built using both the fuzzy theory and the analytic hierarchy process. A RAMS comprehensive evaluation model based on the linear weighted synthesis method was proposed. All of the models and methods are aimed at meeting the needs of this multidimensional component evaluation. This evaluation method was verified using actual gearbox operation parameters. The reliability and availability evaluation curves based on the Weibull proportional hazard model, whose parameters were determined according to the failure data, show that the EMU component reliability and availability decrease as the EMU mileage increases, thus verifying that this evaluation method is reasonable. The calculated EMU gearbox degree of safety is 0.8659, at an excellent level. The evaluated EMU gearbox maintainability is at the moderate level of III. The proposed evaluation method can reflect the relations of the component reliability and availability to the quantities monitored in operation more accurately and more comprehensively and the actual component maintainability and safety levels in a more objective way. It can provide a theoretical basis for managers and design departments to improve and evaluate the performance of the components, determine their maintenance intervals, and develop scientific preventive maintenance strategies in order to reduce their overhaul cost and increase their maintenance efficiency.
The aviation industry is facing an ever-increasing competition to lower its operating cost. Simultaneously, new factors, such as sustainability and customer experience, become more important to ...differentiate from competitors. As aircraft maintenance contributes about 20% to the overall cost of airline operations and can significantly influence other objectives of an airline as well, maintenance providers are required to constantly lower their cost share and contribute to a more reliable and sustainable aircraft operation. Subsequently, new condition-monitoring technologies have emerged that are expected to improve maintenance operations by reducing cost and increasing the aircraft’s availability. As many of these technologies are still in their technological infancy, it is necessary to determine the expected benefit for the airline operations with the given technological maturity and to develop suitable maintenance strategies that incorporate the newly gained insights. With this paper, a discrete-event simulation framework is developed that uses established parameters to describe a condition-monitoring technology’s performance and subsequently develops a suitable prescriptive maintenance strategy. Therefore, it enables the adjustment of the optimization goal for the developed strategy to incorporate performance features beyond the frequently used financial indicators. The developed capabilities will be demonstrated for the tire pressure measurement task of an Airbus A320.
•Prescriptive maintenance extends the scope of legacy maintenance strategies.•Discrete-event simulation framework proposed for holistic stakeholder modeling.•Inclusion of technical maturity levels and fleet utilization degrees of PHM systems.•Consideration of economic and ecologic aspects of maintenance decision making.•Results indicate minimum fleet utilization of PHM systems to achieve cost advantage.
This paper studies the life-cycle performance and cost of reinforced concrete highway bridges subjected to earthquake ground motions while they are continuously exposed to the attack of chloride ...ions. The penetration of chloride ions into the concrete is simulated through a finite difference approach that takes into account all the parameters that can affect the corrosion process. From simulation results, the corrosion initiation time is predicted, and the extent of structural degradation is calculated over the entire life of the bridge. A group of detailed bridge models with various structural attributes are developed to evaluate the changes in the structural capacity and seismic response of corroded bridges. For the purpose of the probabilistic seismic risk assessment of bridges, the seismic fragility curves are generated and updated at regular time intervals. The time-dependent fragility parameters are employed to investigate the life-cycle cost of bridges by introducing a performance index that combines the effects of probable seismic events and chloride-induced corrosion. The proposed approach provides a multihazard framework that leads to more realistic performance and cost estimates.
•Joint inspection and renewal planning for a system of multiple non-identical components.•Considering impact of preventive decommissioning of components that causes future performance loss of the ...system.•Optimal plan is competitive with condition-based maintenance approaches.•Case study of sugar production boiler to evaluate benefit of optimized strategy.
In this paper, a system of multiple degrading components in series reliability is considered where the system performance is a monotonically increasing function of the number of working components. By decommissioning failed components, the system is restored to working order, but the performance loss may only be recovered when the entire system is renewed. The failure risks are managed by inspecting components and conducting preventive decommissioning based on the result. Thus, a complete maintenance and inspection policy will specify when and what components to inspect/decommission and when to renew the entire system. A joint inspection, decommissioning, and renewal plan is developed that minimizes the cost rate and this policy is applied to a boiler heat exchanger operating in a sugar mill. The results show that the proposed policy yields significant savings compared to a benchmark fixed-interval inspection policy and is competitive with a sophisticated condition-based approach. Moreover, in contrast to the condition-based benchmark, the proposed policy provides the entire inspection and renewal plan early in the system's life rather than re-planning after each inspection. Thus, the proposed approach is quite practical — it provides additional predictability in direct expenditures compared to the best condition-based policy and has statistically similar total costs.
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