Maintenance Of Technical Systems Research Articles

APPLICATION OF THE DIBR II – ROUGH MABAC DECISION-MAKING MODEL FOR RANKING METHODS AND TECHNIQUES OF LEAN ORGANIZATION SYSTEMS MANAGEMENT IN THE PROCESS OF TECHNICAL MAINTENANCE

This paper presents a multi-criteria decision-making model based on the application of two methods, DIBR II and MABAC. The DIBR II method was used to define weight coefficients. The MABAC method was used to rank alternatives, and it was applied in a rough environment. Four experts were engaged in defining the criteria and alternatives as well as in the relation of criteria. The model was applied for ranking the methods and techniques of Lean organization systems management in the maintenance of technical systems of special purposes. At the end of the application was conducted a sensitivity analysis which proved the stability of the obtained results.

Preventive maintenance for coherent systems considering postponed replacement

AbstractOne primary objective of reliability engineering is to achieve optimal maintenance of technical systems, which ensures they remain in good operating condition. This paper proposes an age‐based preventive optimal maintenance policy for ‐component coherent systems. Under this proposed strategy, the system begins operating at and undergoes preventative maintenance (PM) at a time . If the system fails before , it will be replaced with a new one. If the system is still functioning at time , an assessment is made based on the number of failed components to determine whether the system should be replaced or allowed to continue operating. If the number of failures at is below a predetermined threshold , the PM time is postponed and a new PM time will be scheduled, and the system continues operating in the interval . Otherwise, the entire system is preventively replaced at with a new one. In this scenario, we use a cost function to determine the optimal values of decision variables , , and . To examine the effectiveness of our proposed model, we analyze some examples of coherent systems using graphical and numerical methods.

Simulation models based on Petri nets for the analysis of maintenance and repair processes of complex technical systems

The presented review analyzes the approaches and methods of using simulation models in the maintenance and repair organization of the complex technical objects and systems. The development of the concept of "Industry 4.0" and the Internet of things involves the transition from periodic and preventive maintenance to predictive maintenance based on the study of processes during the object operation. It is shown that system models based on Petri nets are convenient for describing and analyzing technological processes and equipment maintenance. The effectiveness of timed stochastic colored Petri nets for virtual tests in the design of maintenance and repair procedures in complex systems is revealed. The use of hierarchical Petri nets allows building complex models that describe interrelated processes. A general model based on a hierarchical network is proposed to study the processes of deterioration and degradation of the technical object aggregates and elements and to form a predictive maintenance strategy. The model includes a Gantt chart of production tasks, a set of active and reserve units, maintenance and repair modules. The examples of simulation models on Petri nets for various technical systems are considered. Solutions for flexible production systems, railway bridges, offshore wind turbines, an aircraft fleet, a group of robotic vehicles, and a complex of computer equipment of an enterprise are given. The models of various maintenance strategies are considered and the generality of the models based on hierarchical Petri nets is shown. The article formulates methodological principles for constructing hierarchical networks to simulate the operation and maintenance of technical systems. The article analyzes known software tools for the implementation of timed stochastic colored Petri nets. The summary concludes that the use of simulation models on Petri nets is promising for organizing maintenance and repair of complex technical objects and systems.

Koncept prediktivnog održavanja 4.0 (PdM) u energetici – konekcija sa budućom primenom Industrije 5.0

Industry 4.0 marks the fourth industrial revolution, characterized by the use of cyber-physical systems. In order to achieve an optimal maintenance strategy (but also production), it is necessary to develop systems that support advanced intelligent maintenance systems or smart maintenance technologies. This resulted in the postulates of Predictive Maintenance 4.0, which define the very near future in the field of maintenance of technical systems. Predictive Maintenance 4.0 involves harnessing the power of artificial intelligence to create ongoing insights into detecting causes and anomalies in equipment operations that are not detected by cognitive power. In other words, Predictive Maintenance 4.0 makes it possible to predict what was previously unpredictable. Industry 5.0 focuses on the return of human hands and minds to the industrial framework. The man and machine harmonize with each other and find ways to work together to improve production / maintenance efficiency.

Mathematical Analysis of Criteria for Maintenance of Technical Systems in the Function of Achieving Sustainability

Achieving sustainable development requires strategic efforts involving the entire organization. Maintenance efforts also play an important role. Company management needs to understand and develop an appropriate strategy to achieve sustainable development by applying maintenance performance measurements. The aim of this paper is to present possible ways of analyzing and ranking the impact of certain criteria with respect to achieving sustainability. The paper uses the method of Structural Equation Modeling—SEM in order to determine the most influential variable on the sustainability of maintenance of technical systems. Based on the set theoretical system model, for all its variables in the model, statements were made that describe them, on which 136 respondents gave their views (from 1 to 5, Likert scale) in the territory of the Republic of Serbia. An intuitive F-DEMATEL method was also used to prioritize variables. A team of 10 experts in the field of maintenance of technical systems was compared the criteria A—Application of technical diagnostics, B—Management of maintenance resources, C—Maintenance process planning, and the dependent variable D—Sustainability of maintenance of technical systems. According to experts, the importance of the criteria coincides with the results obtained by a survey with 136 respondents.

Razvoj metode za utvrđivanje veličine zazora u kliznim ležajevima

Introduction/purpose: The purpose of this paper is to present the importance of applying a new diagnostic method with a monitoring system and its capability to reliably determine when and where the problem will occur related to the wear of plain bearings in further operation of the plant, to offer a quality assessment of how the system will continue to function over time, to predict causes of failures and how to eliminate them as well as to provide time for planned maintenance of technical systems. Method: The new method solves the problem of sliding bearing diagnostics by measuring the dynamic trajectories (orbit) of the sleeve in the sliding bearing. Modern methods of technical diagnostics based on the measurement of dynamic parameters and electrical quantities and their analysis enable the support of measuring systems and measurement sensors from different manufacturers. Results: Measurements of the dynamic trajectories of sleeves in sliding bearings determine the values characterizing: normal condition, initial clearance size, further clearance increase, bearing clearance sizes, the moment when the state parameters are close to the upper limit of the allowable clearance, and the specific clearance size when further plant exploitation can cause system failure. Conclusion: The new diagnostic method and monitoring systems can be widely applied in all technical fields: internal combustion engines, hydroelectric power plants, thermal power plants, process plants, and in many other areas. Many monitoring systems, compatibility of devices and equipment of different manufacturers are supported by hardware and software. The calculations of theoretical and experimental dynamic parameters were verified. The method has a wide range of possibilities of application.

Analiza uticajnih faktora koji mogu prouzrokovati greške u primeni savremenih metoda dijagnostike kliznih ležajeva u mašinskim i elektro postrojenjima

Introduction/purpose: The paper presents the application of modern methods in the diagnostics of sliding bearings and the analysis of influencing factors that can cause errors in such an application. Possibilities to determine with certainty when and where problems affect sliding bearings during system operation are presented. It is also shown how the system will continue to function over time. Causes of failures and the manner of their elimination are predicted, as well as the time for planned maintenance of technical systems. Method: The new method solves the problem of sliding bearing diagnostics by measuring the dynamic trajectories of the sleeve in the sliding bearing and by measuring vibration parameters on the inner and outer surfaces of the technical system. The dynamic trajectories of the bearing sleeve are measured with non-contact probes; therefore, the centering of probes in relation to the geometric center of the bearing is very important. Vibration parameters, directly related to the clearance in the sliding bearing, are measured on the inner and outer surfaces of the system. The choice of vibration parameters and measuring points is very important. This method has a number of advantages over other diagnostic methods, as it is easy to access measuring points. Results: By measuring the dynamic trajectory of the sleeves in the plain bearing and vibration parameters on the inner and outer surfaces, the bearing clearance quantities are determined, including: normal condition, initial clearance size, its further increase, bearing clearance sizes, and the moment when the condition parameters are close to the upper limit of the permissible bearing clearance. Conclusion: New diagnostic methods and monitoring systems can be widely applied to: internal combustion engines, all piston machines, hydroelectric power plants, thermal power plants, processing plants, and many other systems.

The formation of the maintenance program and its impact on the increased level of power plants reliability

The paper emphasizes the basic attitudes of complex technical system maintenance programming. Particularly it is performed an analysis and a selection of strategies for condition-based maintenance. The assessment of the established maintenance program varieties effectiveness was carried out by comparison with their basic indicators of effectiveness (for corrective and preventive maintenance).

Analysis of the Types of Maintenance Systems of Technical Equipment and the Assessment of the Characteristics of These Systems for Selecting the Optimal Variant

Abstract The use and maintenance of technical systems throughout their lifecycle aims at achieving goals that allow for high values of productivity and availability characteristics of these systems. In the economic policy of each state or private organization or state institution, there is the right to determine the type of adequate maintenance system within the maintenance strategy adopted. Thus, the types of maintenance systems recognized in the technical domain are analyzed from the point of view of the two previously-mentioned features, productivity and availability, thus making the predictive maintenance system, derived from the preventively-planned one, advantageous for all organizations. It is obvious that the current trend is to spread this predictive maintenance system, according to which the interventions will be carried out before the malfunction occurs, depending on the periodically measured values of global pressure, flow, energy consumption, temperature, current, voltage, vibrations, etc.

Application of lean tools for improved effectiveness in maintenance of technical systems for special purposes

Application of lean tools for improved effectiveness in maintenance of technical systems for special purposes

ПРИМЕНЕНИЕ МЕТОДА РОЯ ЧАСТИЦ ДЛЯ ОПТИМИЗАЦИИ КОМПОЗИЦИОННЫХ ПЛАНОВ ВТОРОГО ПОРЯДКА

Develop methods and software for the optimization of composite second order plans using the method of particle swarm. Composite second-order plans for use in the construction of quadratic mathematical models of the objects and systems. Analysis of the known methods of synthesis of optimal cost and time plans composite second order. Efficiency of the algorithm was tested in the study of the thermal treatment process of the porous material and the regimes of the technical system maintenance. Demonstrated its effectiveness in comparison with the following methods: successive approximation, branch and bound and taboo search

Control cards as a statistical quality control resource

Statistical methods can significantly contribute to the increase of product and service quality, as well as to the increase of institution rating. The definition of optimal, anticipatory and limit values is based on a sample statistical analysis. Control cards represent a very confident instrument simple for use and efficient for process control, by which a process is maintained in set borders. Control cards can thus be applied in the quality control of processes of weapon and military equipment production, maintenance of technical systems as well as for setting standards and increasing quality levels for many other activities.

Models of technical system maintenance management

The existing models of technical systems maintenance management provide required reliability and availability of systems, preferably with as little cost as possible. New concepts, increasingly applied in all areas of life, are based on risk. Such an approach is possible and desirable in the field of theory and engineering of maintenance of technical systems and military technical systems. In this paper, the conceptual definitions of technical systems maintenance, maintenance management models and strategies are given, followed by an overview of strategies and models of maintenance of technical systems, their shematic views and mutual comparisons and trends in the management of maintenance of technical systems, the application of which could lead to savings in the maintenance of both technical and military technical systems.

Equipment and methodology of endoscopy diagnostic

The basic problem in the maintenance of technical systems lies in the confirmation of their working capabilities and discovering malfunctions in case of breakdown. The condition of technical systems can be estimated in the fastest and easiest way by application of contemporary methods of technical diagnostic. The temporary state of technical systems can be estimated by endoscopy diagnostic. That is why it is necessary to get to know endoscopy equipment and define methodology application of endoscopy diagnostic in the maintenance of technical systems. .

Technical system maintenance strategies

This paper gives a survey of recent scientific achievements which has brought changes into the strategies applicable in technical system maintenance systems. The essence of relevant maintenance strategies has been analyzed as well as the advantages disadvantages and effects of their application.

Development of the science of technical system maintenance

Increasing demands for quality of service and cost-effectiveness require permanent improvement of the maintenance science and engineering methods for maintenance of complex engineering systems. Most significant are risk-based maintenance methods being developed over the last few years in particular for complex high risk systems. New European standards on risk-based maintenance will be soon available, providing a higher readiness, lower expenses and lower risks regarding economy, ecology and other influences.

Pouzdanost ljudskog faktora u održavanju tehničkih sredstava

This paper presents one approach to define possible human errors and their contributing factors in maintenance of technical systems. Possible human errors in maintenance are estimated on automatic guns. The paper describes a possible way of estimation of human reliability assessment and performance shaping factors by the standard IEC 300-3-8 'Human reliability'.