Repair Facility Research Articles

Stochastic modeling and parameter estimation of turbogenerator unit of a thermal power plant under classical and Bayesian inferential framework.

The work reported in present study deals with the development of a novel stochastic model and estimation of parameters to assess reliability characteristics for a turbogenerator unit of thermal power plant under classical and Bayesian frameworks. Turbogenerator unit consists of five components namely turbine lubrication, turbine governing, generator oil system, generator gas system and generator excitation system. The concepts of cold standby redundancy and Weibull distributed random variables are used in development of stochastic model. The shape parameter for all the random variables is same while scale parameter is different. Regenerative point technique and semi-Markov approach are used for evaluation of reliability characteristics. Sufficient repair facility always remains available in plant as well as repair done by the repairman is considered perfect. As the life testing experiments are time consuming, so to highlight the importance of proposed model Monte Carlo simulation study is carried out. A comparative analysis is done between true, classical and Bayesian results of MTSF, availability and profit function.

The Problem of Production Situations Identifi cation in the Systems of Production Processes Management of an Aircraft Repair Enterprise

This research provides a new approach to solving the problem of identifying emergency situations in the processes of aircraft repair work by forming a metric space of emergency situations and determining the distance between its points. The main stages of repair of Mi-8 helicopters and their modifications at a typical aircraft repair facility are described. The main stages of solving the problem of identifying production situations are determined. Model has been formed to classify the characteristics of production situations that arise during the repair of Mi-8 helicopters. When analyzing the production situation, it is compared with known situations recorded in the database. If its complete coincidence with known situations is found in the metric space of production situations, then the situation is considered known, the decision maker is issued a list of documents. Otherwise, in the metric space of situations, the point closest to the situation that has arisen is determined, and management personnel are given documents. After the end of the production situation, the updated information on the data, documents and recommendations used by the management personnel in the decision-making process is entered by experts into the computer memory, and the situation itself is included in the database used by the management system. A software package has been developed as part of the production process management systems of an aircraft repair company. The efficiency indicators of the implementation of the identification system of complex production situations at the enterprise are determined.

Диагностика зависимости основного производства от производственной инфраструктуры на основе ансамблевого метода машинного обучения

The rational organization of the production infrastructure of an industrial enterprise has a significant impact on the level of profitability of production. New technologies for integrating business processes are evolving in the face of industrial automation. The aim of the article is to diagnose the level of economic dependence of the core production on the production infrastructure. As a research method, the algorithm of the ensemble method of machine learning “Random Forest” is proposed. The parameters that quantitatively and qualitatively describe the costs of main and auxiliary production, the costs of repair facilities, and the level of production efficiency have been developed. Approbation of the algorithm on the example of chemical enterprises allowed distin-guishing three classes of productions by the nature of the organization of production infrastructure and its par-ticipation in the core production. The quality of the obtained models is evaluated by calculating the risk of mis-classification and the magnitude of cumulative lift, where the class with the most correct classification results is highlighted. Results obtained are primary diagnostics of the organization and capacity utilization of the produc-tion infrastructure in order to make decisions on business process restructuring.

PERENCANAAN BANGUNAN MCK UNTUK KEBUTUHAN MASYARAKAT DI KAMPUNG SETU TONGGOH

MCK is one of the public facilities which are usually shared by several families to bathe, wash and defecate in a settlement which can be judges as a location with a fairly dense population and low economic. One of villages in Bogor Regency still uses MCK because it doesn’t have a private toilet in each house. The number of people who use the MCK is 25 people. The MCK used by the community is still not suitable for use, so that they are more flexible and comfortable when used, we plan to repair the MCK. For the sake of creating a suitable bathroom for use and realizing MCK that there are no proper repair facilities. This research contains that the availability of a new MCK design can help the community rebuild the MCK. Hopefully this MCK planning can be realized because with proper planning it can minimize bathroom problems faced by the community.

EFEKTIVITAS PENGGUNAAN JALUR LAMBAT PADA RUAS JALAN DR. LUKMONOHADI DAN DR. RAMELAN KUDUS DI KABUPATEN KUDUS

Kudus street is a national road that connects Jakarta-Semarang-Surabaya-Banyuwangi, on this north coast road as the need for mobility of goods delivery or mobility of residents between cities. On the way Dr. Lukmonohadi – Dr. Ramelan has a slow lane on the left side of the road. The purpose of the existence of the slow lane on road DR. Lukmonohadi-Dr. Ramelan is to smooth traffic and reduce the fatality rate of accidents in the fast lane, but due to very high shopping and industrial activities that can interfere with performance on these roads. The purpose of this research study is to review the effectiveness of the slow lane on the Dr. Lukmonohadi-Dr. The Ramelan is working properly or not. From the results of the analysis of traffic performance measured using the degree of saturation (DS) for Road Dr. Lukmonohadi of 0.57, while Road Dr. Ramelan is 0.61. From the level of congestion that can be obtained from the value of the side barriers that Dr. Lukmonohadi until Dr. Ramelan is included in the medium side resistance class (M). Based on the comparison of the accident rate from 2016-2021 the number of accidents continues to increase. The recommended recommendations are that it is necessary to repair and add road facilities such as repair of separator paint, faded road markings, addition of zebra crossings in pedestrian-congested locations and asphalt repairs on slow lanes because there is a lot of asphalt that is peeling and has holes, it is very dangerous for road users crossing it. Based on the results of the analysis for the slow lane, it can be concluded that the slow lane has been effective in facilitating traffic flow to reduce the number of accidents on the fast lane.

МАТЕМАТИЧЕСКАЯ МОДЕЛЬ ОПЕРАТИВНОСТИ РЕМОНТА АВТОМОБИЛЬНОЙ ТЕХНИКИ

The use of a probabilistic approach is proposed in the modeling task. Several repeatable groups of the same type of operations are considered - the search for the cause of failure and its elimination. Based on the experience of previous repairs of the same type of car components, the distribution series of values Pm (probability of repair of certain nodes) and Pn (probability of failure of certain nodes) are set. The model takes into account the qualifications of engineers and technicians of the service station, the availability and capabilities of mobile and stationary monitoring and repair facilities. After determining the probability of correct troubleshooting and planning a certain algorithm of maintenance operations, the repair efficiency is estimated as the ratio of the probabilities of performing repairs for a given time and the average repair time. The desired probability density, given the multiphase nature of the process, is determined by the method of multiple convolution. The resulting model allows us to solve two reciprocal problems. Firstly, to determine the optimal repair time, provided that diagnostic and repair tools are equipped, as well as the qualifications of technical workers. Secondly, at a given repair time, determine the required characteristics of diagnostic equipment, maintenance facilities and personnel.

A Markov Regenerative Process Model for the Dependability and Performance of a Two-Unit Multi-State System under Maintenance

Preventive maintenance (PM) is a key aspect for industrial, production and generally technological systems, since it can prevent unexpected breakdowns and their consequences. However, PM incurs additional cost and thus system designers should carefully examine how and when to implement it. Beyond this, modeling correctively the structure and the evolution of the system is of critical significance when designing the appropriate PM strategy. In this paper, a two-unit multi-state parallel system with one repair facility, which can model various industrial systems like power generation or pump systems, production systems or even computing systems, is considered, in which PM is enabled to prevent failures and improve system's dependability and performance. Given some specific system characteristics, a Markov Regenerative Process is proposed to be used to accurately model the evolution of the system in time. The asymptotic availability, the expected downtime and the expected operational cost are evaluated as measures for the system dependability and performance correspondingly. The aim is to determine the PM policies that optimize these measures either separately or jointly, through formulating and solving the appropriate optimization problem. The theoretical framework is illustrated through a numerical example for a pumping station consisting of two centrifugal pumps working in parallel.

Joint Inventory and Scheduling Control in a Repair Facility

Operations Management in a Repair Facility Capital goods are machines or products that are used in the production of goods or service deliveries. Maintenance service providers keep spare parts on stock so that, whenever a critical component of a capital good breaks down, the broken part is replaced with a spare part to prevent long and costly downtime. In “Joint Inventory and Scheduling Control in a Repair Facility,” Özkan and van Houtum study inventory and repair scheduling decisions of a maintenance service provider for repairable capital goods. In case of a stock-out, the service provider should decide whether to back-order the demand or execute an emergency repair, which is an urgent but expensive repair operation for a broken part. The authors derive a simple and intuitive decision rule stating if the emergency repairs are necessary to achieve a close-to-optimal system performance. Moreover, they propose a simple, intuitive, and easy-to-implement heuristic control policy that performs well in numerical experiments.

Tyre Pressure Monitoring System with Compressor

Abstract: Around 15 million two-wheelers are sold annually in India, where one in three homes has a two-wheeler. The country produces 20 million units of two-wheelers annually. Severe underinflation can result in mechanical and thermal stress brought on by overheating, which can very quickly cause the tyre to blow out. Failures of this nature may result in dangers and mishaps that jeopardise not only the rider but also those around him or her. Under-inflated tyres cause tread separation and tyre failure, resulting in 40,000 accidents, 33,000 injuries, and over 700 fatalities each year, according to average country estimates. However, when taking into account India's population, these figures may soar due to a high number of people owning more 2- wheelers, having less time to physically check, and being unable to routinely get their cars inspected at a repair facility. Without the riders' knowledge, the aforementioned issues will occur more frequently. This project focuses on designing and creating a direct tyre pressure monitoring system (TPMS), which uses a pressure sensor to measure air pressure taken straight from the tyre. The rider does not need to get out of his vehicle and manually pump air into his tyres when the TPMS detects a reduced tyre pressure because the TPMS and the compressor unit are working together to supply the air to the tyre. Energy is provided to the gadget either by a dynamo or a backup battery. To ensure consistency and accuracy in reporting the pressure and providing enough air to the tyre, the key components must be calibrated. Although there are numerous challenges and constraints, this prototype is a promising product for use in the real world.

Stochastic Assessment of k Operational State System with k-out-of-n:G Working Scheme with Employing Copula Repair Approach

This paper is a probabilistic performance study of a repairable complex system with three subsystems coupled in a series configuration. All three subsystems have been differently configured and also have different operational schemes. The first subsystem has [Formula: see text] units and works under the [Formula: see text]-out-of-[Formula: see text]:G scheme, the second subsystem has four identical units and associates with a defined work scheme 2-out-of-4:G, however, the third subsystem has two indistinguishable units and works under the 1-out-of-2:G policy. The units’ failure rates of the subsystems are different but constant and follow an exponential distribution, however, there are two types of repair facilities available for repair general and copula repair. Under the consideration of the system with the operational duration, the failed unit was replaced with a new one and it was assigned for repair. In the complete shutdown condition, a copula repair has been employed to repair the system. Traditional reliability measures have been studied for different values of failure and repair through supplementary variable and copula approaches. The numerical computations for securing different values of [Formula: see text] and [Formula: see text] have been exhibited and tables and graphs predict the future behavior of the system performance. In the conclusion section, the effect of reliability measures has been highlighted.

North Indian winter fog, barbed wire, drunken driving and neck trauma

Inebriated motor cyclists in dense fog of North Punjab often lose control and run into the barbed village fencing. The wire drapes the front of the neck and penetrates the tissues to varying depth, depending on the intensity of trauma. This is commonly noted between the cricoids and the mandible. Timely surgical intervention, intoxication and speed checks can reduce the incidence of poor visibility related mishaps. An individual sustained and survived penetrating barbed wire injury by wrapping his head gear around his neck and drove to a rural health care facility for a primary repair of his neck.

THE INFLUENCE OF STRATEGIC RISK MANAGEMENT, CONFLICT MANAGEMENT AND CRISIS MANAGEMENT ON THE MANAGEMENT PERFORMANCE OF NAVY BASE AT RANAI NATUNA WITH ORGANIZATIONAL CITIZENSHIP BEHAVIOR

The purpose of this research is to follow up on the increasing escalation of conflict in the South China Sea, the Indonesian National Navy as the main component of the State's defense at sea supported by the readiness of the defense equipment, especially the Unitary Republic of Indonesia, to routinely carry out operations in the Natuna. In order for the Unitary Republic of Indonesia to optimally carry out operations in the Natuna Waters, it must be supported by appropriate maintenance and repair facilities at the Indonesian National Armed Forces base in Natuna. The analytical method is carried out through explanatory research, with the PLS/SEM application. The concepts and problems studied look at the causal relationship, then explain the variables that cause the problems studied. The research sample consisted of 187 leaders and personnel at Lanal Ranai. The results of this research are strategic risk management, conflict management and crisis management that affect management performance. Organizational citizenship behavior influences management performance. Likewise, strategic risk management, conflict management and crisis management have an effect on management performance mediated by organizational citizenship behavior in the Ranai Natuna Naval Base Border Area. Theoretical implications with the existence of strategic risk management, conflict management and crisis management through increasing its dimensions will be able to improve management performance in the Ranai Natuna Naval Base Border Area. so as to increase the trust and loyalty of related parties. Managerial implications that need to be implemented are strategic risk management, conflict management and crisis management which greatly affect management performance.

A heuristic maintenance scheduling framework for a military aircraft fleet under limited maintenance capacities

In many military scenarios, an aircraft fleet is oftentimes required to execute a sequence of missions with finite breaks between two adjacent missions. The performance of a fleet can be significantly improved by conducting appropriate maintenance activities on damaged aircraft during each break. The maintenance scheduling of such a scenario is, however, inherently subject to the limitation of maintenance capacities, such as repairpersons and repair facilities. Each maintenance activity contains multiple maintenance jobs that must be sequentially carried out, whereas the structural dependence of the constituent parts of each aircraft produces additional constraints to the sequence of maintenance activities. In this article, a new maintenance scheduling framework for a fleet of military aircraft is formulated to maximize the expected fleet readiness. Each maintenance activity requires specific repair facilities and repairpersons, and the limited maintenance capacities have to be arranged in a holistic manner. Due to the unexpected arrival of the next mission on battlefields, the uncertainty associated with the time duration of a break is also considered. Two heuristic algorithms are put forth to resolve the resulting optimization problem efficiently. Comparative studies show that the proposed heuristics outperform other alternative algorithms and are promising to solve large-scale problems.

Management of the development of a metallurgical company on the basis of the algorithm of the pre-investment analysis

The article is devoted to the development of methodological approaches to assessing the effectiveness of investments in innovations and repairs of Russian metallurgical companies based on an analysis of the state of innovation and technological potential in order to maintain competitiveness in the face of tougher sanctions. The analysis of sources and directions of investments and comparison of the current internal rate of return in the leading companies in the metallurgical sector were carried out: Severstal, MMK, NLMK, EVRAZ; their investment activity was studied and the predominant selfinvestment in the development of companies and interest in financial parameters and global trends were confirmed to the detriment of the material component of production. The problem of disunity of owners, managers of the main production, repair facilities and top management in making investment decisions is detailed and methods for its solution are proposed through the use of a company's preinvestment analysis algorithm based on the methodology of predictive analysis of large data arrays. The methodological basis is the theory of strategic management and investment analysis. Methods: classification, comparison, grouping, economic and mathematical modeling, predictive analysis and algorithms. The methodology for evaluating investment projects using the modified internal rate of return (MIRR) has been refined. An algorithm for analyzing the investment environment of metallurgical companies is proposed based on taking into account the service life of equipment and ranking it depending on the need for repair or renewal. The updated analytical tools will be of interest to industry enterprises, corporations and government agencies in substantiating the strategy of innovative development. The developed approaches are of scientific interest in the study of contradictions between production, top management, owners of metallurgical companies and the state.

Aircraft maintenance and repair using “Mobile complex of unified aircraft repair facilities”

This paper presents a projected model of aircraft Maintenance Repair and Overhaul (MRO) using “Mobile Complex of Unified Aircraft Repair Facilities” (MCARF). MRO using MCARF is part of the “Before Failure Detection” and “As Conditioned” MRO strategies. The MRO project with MCSM allows building a concept of control of the aircraft life cycle stage - operation in conditions of rapid response to current aircraft repair needs, in the presence of limitations in the required maintenance and repair facilities and the possibility of their rapid delivery.

Reliability Measures Assessment of Solar Water Heating System Under Copula and General Repair Facilities

Reliability Measures Assessment of Solar Water Heating System Under Copula and General Repair Facilities

FEATURES OF REPAIRING GRAIN HARVESTERS AT INDIVIDUAL SERVICE ENTERPRISES OF ENGINEERING SERVICE OF AIC OF KRASNODAR REGION

In this article, we considered the issues of optimizing the repair of combine harvesters at a separate repair facility of the engineering service of the agro-industrial complex of the Krasnodar Territory - RPK Yarovit. (Research purpose) The research purpose is substantiatiation the need to update and implement regulatory and technical documentation when carrying out all types of technical support of agricultural machinery at specialized enterprises of the engineering service of the agro-industrial complex throughout the entire life cycle of machines: repair, maintenance and disposal. (Materials and methods) They showed separate cycles of repair and modernization of combine harvesters using innovative technologies at the Yarovit RPC enterprise, presented illustrative materials that give a visual representation of the condition of individual units and aggregates of combine harvesters that are subjected to repair impacts. (Results and discussion) The standard GOST 34915-2022 «Combine harvesters and their assembly units» was introduced at the Yarovit RPC enterprise. Commissioning and release from repair». It was determined that as a result of using the standard, relations between the repair company and Rostechnadzor bodies are normalized in terms of registration of repaired combines, the most painful issues between the customer (owner of combines) and the contractor (repair company) on the quality problems of repaired combines are removed. (Conclusions) The experience of repairing combine harvesters at a specific service enterprise of the engineering service of the agro-industrial complex of the Krasnodar Territory showed the need to implement the GOST 34915-2022 standard «Combine harvesters and their assembly units. Commissioning and release from repair» at most repair enterprises of the engineering service of the agro-industrial complex of Russia.

Ռազմական գործողությունների վարման ժամանակ սպառազինության և ռազմական տեխնիկայի վերականգնման ուղղությամբ արդյունաբերական ձեռնարկությունների հնարավորությունների օգտագործումը / Using the capabilities of industrial enterprises to restore armaments and military equipment in the course of conducting military operations

One of the distinguishing features of modern military conflicts is the increased failure of armaments and military equipment (AME) due to the mass use of the high-precision weapons and UAVs. As a rule, the capabilities of the military unit to restore samples of military equipment that collapsed during military actions do not make room for solving repair tasks (especially for medium and major repairs) at the required scale in a relatively short period of time. Moreover, in this regard, it is best to turn to international experience of the restoration of military equipment. It can be noted that in the RA Armed Forces, the principles of the organization of the restoration of military equipment have been developed on the basis Soviet experience, which proves their effectiveness and viability during combat operations. Meanwhile, the industrial enterprises have been assigned a major role in replenishing the losses of military equipment, which implies that it is necessary to use their potential capabilities in order to solve the tasks of maintaining the combat effectiveness of the Armed Forces with regard to the military equipment. With a view on the experience of a number of modern wars and armed conflicts, we can identify some issues of concern regarding the restoration of military equipment, referring to both the evacuation of broken equipment samples to industrial enterprises, and the implementation of their repair. Withal, the problem of providing these enterprises with military-technical equipment necessary for the timely restoration of the combat capability of broken military equipment is of particular importance. Based on the research conducted, proposals and recommendations have been developed on the possible solution of existing issues of concern regarding the creation of additional repair facilities and their provision with the necessary amount of military-technical equipment.

Reliability analysis of redundant retrial machining system subject to standby switching failure

ABSTRACT With the rapid development of the Internet and hardware, cloud computing has been widely applied in various industries. Supporting services using high-quality and reliable communications equipment with an effective repair system is essential. A potential application of a cloud computing system for online data analysis services with multiple virtual machines is presented herein. The primary and standby virtual machines are both assumed to be unreliable. In this study, we analyze a retrial machine repair system with warm standbys and switching failure. When the repair facility is inaccessible, the failed machine joins a retrial pool and tries to access the repair service after a random period. The Laplace transform technique and matrix-analytical method are employed to derive the system performance measures of the reliability and mean time to failure. Moreover, numerical results are provided to investigate the effects of system parameters on system performances.

Stock reallocation policy for repairable service parts in case of supply disruptions due to extreme weather events

Climate change and global warming are resulting in extreme weather events that are occurring with increased frequency and intensity. These events often lead to supply disruptions of repairable assemblies which may be more damaging for regular operations of the main equipment (aircrafts and helicopters). In this paper, we design an inventory system for repairable service parts with a central repair facility (Depot) and several service parts inventories at the bases. When a part fails, it is replaced with part from inventory held at the base. The faulty part is transported back to the depot, repaired, and transported back to any of the bases following the stock allocation policy. However, extreme weather events may result in a scenario where the supply lines between the depot and one or more of the bases are disrupted. In such cases, a stock reallocation policy becomes a prudent approach in which the parts are transported within the bases to avoid a backorder situation. In order to service an aircraft or a helicopter at a base with low-level inventory, parts are optimally diverted from another base with higher stock. In this context, we also have to decide about the optimal time for initiating reallocation. We formulated the stock reallocation model as a Markov Decision Process (MDP) that uses an aggregate queuing model to approximate the relative value function (RVF) of the optimal stock reallocation policy. The results of the numerical experiment show that such a rule performs very close to optimality. We also conduct a sensitivity analysis to evaluate the effects of different problem characteristics on the optimality gap.