Papers by Keyword: Preventive Maintenance

Abstract: The industrial manufacturing systems are increasing in complexity to market changes. One of the best challenges of this complex systems is reach the schedule production baches without unexpected failures, looking for the zero defects. The presence of Multistage Machines (MSM) at industrial manufacturing systems allow to produce big batches in very short times. Nevertheless, these types of machines normally are manufactured as an ad hoc machine and have not maintenance strategies tested for preventive or predictive actions. Also, if a component of this machine fails, the entire machine fails, causing the loss of the production batch. Recent publications have developed local preventive and predictive maintenance strategies for industrial multistage machines, as an individual machines with local work conditions in different places. Nevertheless, the accumulated knowledge of a MSM cannot be used as relevant information to improve maintenance actions in other MSM. This research develops and proposes a network system, called Master Maintenance Management (MMM) to establish a continuous connection with all MSM, working as a datalogger who collects all relevant information for all MSM and suggest maintenance warning predictive and preventive warnings for machines and use them for preventive actions in the rest of each MSM working at the same conditions. So, the capability of one machine for take a local predictive action is performed by the MMM to take a preventive action in the other machines connected to the same network. This approach has been developed with thermoforming multistage machines, who have local preventive maintenance strategy based on individual maintenance times and predictive maintenance strategy based on some distributed sensors in the machine and a behaviour algorithm, called Digital Behaviour Twin (DBT). The most relevant benefits of this approach are the limitation of unexpected failures in the connected machines by using accumulated information of other MSM, the change of the predictive actions to preventive actions, and the machine perform by design changes suggested with all the database collected.

Abstract: The generation system is an important part of the power system. The problem of generator maintenance scheduling is provided to construct optimal generators preventive maintenance schedules. It aims to improve economic benefits and achieve reliable operation of the power system while satisfying the system and maintenance constraints. In this paper, the binary crow search algorithm is proposed for solving the scheduling problem. This model would schedule maintenance scheme and commitment status of generating units while the objective functions are achieved. The crow search algorithm is a new meta-heuristic optimizer, which has its implementation very simple and easy compared to other optimization techniques. To verify the robustness and effectiveness of the proposed binary crow search optimizer, three test systems namely 6–unit, 21–unit system, and IEEE reliability test system are considered over the planning horizon of 52 weeks. The proposed optimizer is implemented in the MATLAB programming environment. Techno-economic aspects are considered for the generator's maintenance scheduling problem as reliability enhancement economic cost-minimizing issues. The proposed binary crow search optimizer is developed for single and multi-objective frameworks. The simulation results show the proposed binary crow search technique effectiveness and feasibility compared with previously optimizer in solving the generators maintenance scheduling problem with better convergence rate.

Abstract: It is the function of concrete cover to protect reinforcement against corrosion from environmental attack. However, reinforced concrete structures in most cases suffer from corrosion of steel reinforcement and their service lives will be reduced. The steel in concrete is always prone to corrosion attack, and the reason being that concrete cover is porous in nature. Fluids and dissolved ions can impregnate through pore space or through cracks and come in contact with reinforcement. Preventive maintenance is the best corrosion control mitigation measure for reinforced concrete structures. This paper highlights the causes of corrosion in non-coastal areas like Kigali in Rwanda. Condition assessment of two reinforced concrete buildings in Kigali has been made based on structural survey. It was found that Crack width varies up to 2mm in column and beams. It is also suggested that to improve the life span of the columns and beams by retrofitting with advanced materials and the new structures are to be constructed with corrosion monitoring systems.

Abstract: This study is on the integrated planning problem of maintenance and production within the frame work of a system subject to periodic preventive replacements with minimal repairs in case of unplanned failures. A model was developed using the overall cost by considering the interdependence between the maintenance plan and the production schedule. The overall cost contains two parts: the costs of launching a product, production, storage and breaking on the demand and the preventive and corrective maintenance costs for multi-periods and multi-products systems. The purpose of this integration is to find simultaneously the optimal cycle T at which the preventive maintenance takes place and the optimal values of lot-size by adding the setup time constraint. Using the mixed integer linear programming these optimal values minimize the total cost over a finite horizon. The results show that the proposed model performs quite well and opens new research direction for future improvements.

Abstract: This research aims for guidance in improving the productivity of the machines in case study of refinery plant based on the principle of preventive maintenance of machinery applications. This is to increase the availability and improve the reliability and overall equipment effectiveness (OEE) of the machines. From the data collected showed that high cost of maintenance is quite high caused by non-standard maintenance and no prioritization of machine maintenance. Therefore, the researchers proposed a maintenance program developed based on reliability engineering with failure mode and effects analysis (FMEA). FMEA was the first brought to analyze the root causes of machine failure and to evaluate the risk priority number (RPN). The data was performed preventive maintenance plan standardized the maintenance system in order to optimize maintenance task and maximize the efficiency of machinery. After applying FMEA, the result showed that the chance of failure in equipment was very low (1 time in 12 years) after the scheduled maintenance plan and opportunities to detect damage in advance was moderate to high. Therefore, the equipment with a moderate to high risk is likely more damage than the first round of maintenance (5 years). Moreover, the average of the residual risk level analysis of the machine decreased by 59.165% and overall equipment effectiveness (OEE) increased from 92.66% to 98%

Abstract: Lack of preventive measure is currently the problem that implicates poor maintenance outcome. Scheduled maintenance is claimed as a maintenance strategy to tackle the problem. However, the effectiveness of scheduled maintenance can be greatly influenced by the length of predetermined maintenance interval. Thus, this paper aims to study the relationship between length of predetermined maintenance interval and maintenance performance. The literature review identifies the length of predetermined maintenance interval as an importance characteristic of scheduled maintenance strategy. A quantitative approach is adopted and carried out through questionnaire survey. Subsequently, descriptive analysis and correlation analysis are used to analyse the collected data. Then, research result demonstrates that the length of predetermined maintenance interval is significantly correlated to the maintenance performance. The length of predetermined maintenance interval must be considered in maintenance planning and execution. The research recommends continuous monitoring or regular inspection of building systems and components to identify their condition and update the length of predetermined maintenance interval regularly. Consequently, the effective maintenance execution helps to avoid systems failure occurs and optimises maintenance performance.

Abstract: One of the basic means of improving the reliability of technical equipment is increasing their reliability through targeted maintenance. When designing any technical equipment should be chosen minimum necessary set of technical resources that are necessary to the achievement of the required scope and quality of its functions. By setting an appropriate preventive maintenance plan can be timely and effective interventions to prevent adverse consequences of failure. This paper describes the proposal of optimal plan of preventive maintenance of experimental equipment designed for 3D machining rotating parts with AWJ technology.

Abstract: Wear particle analysis as a nondestructive evaluation technique is an effective method to determine the lubricating oil conditions within different lubricated machines, thus monitoring wear modes and imminent failures in these machines, such as gear-boxes and engines. Ferrographic analysis of wear particles in lubricating oil could give complete information about ferrous and non-ferrous solid debris present in the oil sample. Spectrometric oil analysis could give a direct measure of elemental metal content in the oil such as Iron, Aluminum, Lead and Cupper. These techniques provide cheap, fast and easy methods to use predictive maintenance methods which can replace other conventional methods. The objective of the present study is to apply wear particle analysis technique for condition monitoring of an industrial gear-box transmission over two year’s period of time. This gear-box belongs to one of the machines of the Oriental Weavers Company (OWC), one of the largest carpet manufacturers in the world. Spectrometric and ferrographic analysis were used where quantitative and qualitative changes in the concentration and size distribution of different particles were analyzed and compared to baseline values.

Abstract: Recent approaches to preventive maintenance have shifted from periodic maintenance based on static parameters to a continuous and a periodic maintenance that deploys high-tech tools to track remotely the “health” of equipments. In this paper, we propose an approach to maintain a high level of reliability and to achieve the maximum efficient use of the working parts within vehicles and machines. This paper marks the use of various techniques in the remote maintenance and diagnostics by means of classical and new methods for monitoring equipments remotely. And hence identifying their failure at earlier stages and preventing their breakdown. The technique relies on an onboard device that monitors and analyses the vibrations of the targeted parts using local knowledge stored within the middleware data base and global knowledge obtained remotely from the server.

Abstract: In consideration of the situation that the conventional preventive maintenance inspection cycle of the repairable device is not be changed as long as it is determined, based on continuous-time Markov processes, the repairable device preventive maintenance control strategy is studied. The preventive maintenance model is established, i.e., its state transition diagram, steady state value of the model is calculated, the control policy of device’s check rates based on device status is proposed, and the proposed control policy is simulated and confirmed using MATLAB. Simulation results show that under the proposed control policy rule, the actual operation curve of the system can well track the desired operation curve of the system, and finally can achieve the desired steady state value. Studies have shown that the method has some help to strengthen device maintenance management, improve device maintenance strategies, ensure that the device is repaired according to the state, and reduce maintenance costs of the device.