Machine Repair Research Articles

Reliability analysis and sensitivity analysis of retrial machine repair problems with multiple vacations and the recovery policy

Reliability analysis and sensitivity analysis of retrial machine repair problems with multiple vacations and the recovery policy

Analytical Investigation of Phthalates and Heavy Metals in Edible Ice from Vending Machines Connected to the Italian Water Supply.

Edible ice is often produced by special machines that can represent a source of significant chemical and microbiological contamination. In this work, the presence of phthalic acid esters (phthalates, PAEs) and heavy metals in ice cubes distributed by 77 vending machines installed in two different zones in southern Italy and fed by water from the public water supply was investigated. Solid-phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GC/MS) was used to evaluate contamination with four PAEs, which were selected because they are commonly used in the production of food-contact plastics, while inductively coupled plasma mass spectrometry (ICP/MS) was used to quantify the heavy metals. It was found that ice samples, especially those from one of the two considered zones (zone 2), exceeded the dibutyl phthalate (DBP) threshold limit value; some ice cubes from the other zone (zone 1) instead showed levels of both lead (Pb) and nickel (Ni) up to one order of magnitude higher than those observed in samples collected in zone 2 and higher than the maximum permitted values (European Directive n. 2184/2020). Since the water source connected to the ice vending machines was found to be free from significant levels of all considered target compounds and metals, the high levels of DBP, Ni, and Pb in ice cubes could be attributed to the components and/or to the state of repair of the ice vending machines themselves.

Customer Satisfaction Based on Service Quality and Price

Industrial machine repair services is one of the service industries where new company actors have emerged and innovated as a result of the growth of the service sector. One strategy to outperform the competition is to prioritize customer satisfaction. A few important factors that affect customer satisfaction are price and the quality of the services rendered. The purpose of this study is to ascertain how pricing and service quality at PT. Karya Utama Wijaya Sakti relate to each other in terms of customer satisfaction. The sample size is one hundred clients, and multiple linear regression analysis is the method employed. The study's findings show that, albeit slightly concurrently, both the pricing and the quality of services at PT. Karya Utama Wijaya Sakti have a positive and significant impact on customer satisfaction.

Particle Swarm Optimization for a redundant repairable machining system with working vacations and impatience in a multi-phase random environment

With the increasing reliance on cloud computing as the foundational manufacturing systems with intricate dynamics, featuring multiple service areas, varying job arrival rates, diverse service requirements, and the interplay of failures and impatience, significant analytical challenges arise. Queueing networks offer a powerful stochastic modeling framework to capture such complex dynamics. This paper develops a novel, exhaustive queueing model for a finite-capacity redundant multi-server system operating in a multi-phase random environment. The proposed model uniquely integrates real-world factors, including server breakdowns and repairs, waiting servers, synchronous working vacations, and state dependent balking and reneging, into a single queueing model, representing a significant advancement in the field. Using the matrix-analytic method, we establish the steady-state solution and derive key performance metrics. Numerical experiments and sensitivity analyses elucidate the impact of system parameters on performance measures. Additionally, a cost model is formulated, enabling cost optimization analysis using direct search method and Particle Swarm Optimization (PSO) to identify efficient operating configurations.

Cost analysis for machine repair problem under triadic policy with discouragement and multiple working vacations

ABSTRACT This study portrays the steady-state assessment of controlling the service of two removable repairmen for a machine maintenance problem with discouragement and multiple working vacations under a triadic policy. The L operating machines constitute the entire system, and it is believed that failing machines will be repaired in accordance with triadic policy and repairmen will take multiple working vacations. During the working vacation period, one repairman continues providing service and goes for another vacation as soon as queue of failed machines becomes empty. The system steady state equations are solved recursively and various performance metrics are established for constructing a system total expected cost function. Cost optimization is performed, and the optimal cost is compared using several approaches, including Particle Swarm Optimisation (PSO), the Artificial Bee Colony (ABC) algorithm, and the Genetic Algorithm (GA). The convexity behavior of the expected cost function, among choice variables with restricted region also presented graphically. Furthermore, the paper includes computational findings illustrating the impact of different parameters on the estimated optimal service rate and optimal thresholds, as well as a case study demonstrating the practical use of the designed model.

AUTOMATED COMPLEX FOR MEASURING THE WINDING TEMPERATURE OF TRACTION ELECTRIC MACHINES DURING THEIR HEATING TEST

Purpose. The development and implementation of automated complexes for testing traction electric machines of rolling stock at the current stage is an extremely important task. Automated test complexes provide an opportunity to significantly increase the quality and efficiency of tests on traction electric machines. Thanks to the use of advanced technologies, these complexes ensure accurate data collection and analysis during tests. One of the main advantages of automated complexes is the reduction of cost and labor costs for conducting tests. Instead of manual intervention by operators, automation systems can perform many tasks automatically, saving time and reducing labor costs. Methodology. The methodological basis of the research is analytical research methods based on the compilation of a calculation system of differential equations based on the accepted test scheme, as well as the development of an algorithm for conducting tests on a designed stand. Findings. The proposed test complex allows to conduct tests of collector traction electric machines, to determine the excess temperature of the windings of electric machines without the need to stop them. The functional scheme of the measuring complex allows you to automatically record the parameters of the tested electric machines, and if necessary, it is possible to output the test results to a computer with the subsequent formation of the test protocol in electronic form. The accuracy of the determination of the measured parameters is ensured by the accuracy of the measuring devices and the algorithm of the measuring complex. Originality. The proposed automated measuring complex is a big step in the direction of improving the efficiency and reliability of heating tests of traction electric machines. One of its key advantages is the ability to perform tests without stopping the machine, which significantly reduces the time and costs of conducting tests. Automatic registration of measured parameters allows to record several controlled indicators at the same time, which provides a more complete and objective assessment of the state of the electric machine during testing. This complex not only facilitates the testing process and reduces the cost of time and resources, but also increases the reliability of the obtained results, which is important for manufacturers and operators of transport systems. In general, the automated measuring complex opens up new opportunities for increasing the efficiency and reliability of testing electric traction machines, contributing to the further development of transport technologies. Practical value. The implementation of the obtained results by enterprises for the repair of traction electric machines of rolling stock will allow to reduce the material costs of carrying out repairs while simultaneously improving the quality of the conducted tests.

НАУЧНАЯ ШКОЛА ПРОФЕССОРА ПЕТРА ВАСИЛЬЕВИЧА СЕНИНА

The strategic task in the field of modern higher education is to develop the research potential of the university, to educate scientific staff. The effectiveness of this process depends on the successful functioning of scientific schools. In this regard, the research aimed at studying the experience of the author's scientific schools is relevant. (Research purpose) The research purpose is analyzing the concept and features of the scientific school as a form of personal growth and formation of researchers at the university using the example of research in the field of developing technologies for high-resource repair of machinery and technological equipment using metal coatings with specified functional properties (experience of the scientific school of professor P.V. Senin). (Materials and methods) Applied scientific and theoretical methods of analyzing the experience of the functioning of a scientific school, summarized and interpreted the criteria for its success as a form of personal growth and becoming a researcher at a university. Scientific and technical literature and publications in the field of humanitarian knowledge were used in the study. (Results and discussion) The experience of the P.V. Senin scientific school has shown that the implementation of the mechanisms of personal growth and formation of researchers at the university is the inclusion of students in the process of the scientific school, based on the creation of innovation centers, research laboratories, student teams, as well as the publication activity of the community of scientists on the basis of general theoretical and methodological approaches reflecting common research results. It was determined that the priority task of the scientific school is the interaction of university science and economic sectors aimed at creating technologies for high-resource repair of machines using the method of electric spark processing. (Conclusions) The results of the activities of the P.V. Senin scientific school allow us to consider this structure as a point of personal growth and professional development of a research student, a young scientist.

The Influence of Loyalty and Productivity on Employee Performance PT. Kreasindo Abadimas Medan Partners

Mitra Kreasindo Abadimas is a private company engaged in the sale and purchase of spare parts and machine repair services that has been operating since 2017. In its operational activities, the company experiences problems and problems that have not been resolved, namely disruption of employee performance due to lack of time to meet needs. The employee and the company are only asked to work continuously. Problems that allegedly cause poor employee performance in company operations are employee loyalty and low employee productivity. Simultaneous hypothesis test results show that simultaneously, loyalty and work productivity have a positive and significant effect on employee performance at PT. Kreasindo Abadimas Partners. The result of partial hypothesis test shows that partially, each variable of loyalty and work productivity has a positive and significant effect on employee performance at PT. Kreasindo Abadimas Partners.

Implementation of Preventive Maintenance Management on Multiline Wrapping Machines to Squirt the Production Process at PT Yili Indonesia Diary

PT. Yili Indonesia Diary is a manufacturing company that produces ice cream under the Joyday brand. The problem that occurs is that there are packaging defects resulting from the packaging machine, namely Multiline Wrapping. Maintenance management is interpreted as an appropriate strategy to manage when maintenance must be carried out on machines. Therefore, the production process in the factory will not be hampered as long as the machine runs smoothly. Preventative maintenance needs to be carried out as the first step so that the machine is always ready to use and can avoid significant damage. The aim of this research is to analyze the implementation of preventive maintenance management on Multiline Wrapping machines. Qualitative research methods were adopted in this research and data were collected through observation, documentation and literature study. The research results explain that the machine maintenance strategy, especially for Multiline Wrapping machines at PT Yili Indonesia Diary, includes, among other things, Preventive Maintenance, Machine Repair, Replacement, and Opportunity Maintenance. Machine maintenance is very important because it can speed up the production process.

Cost optimization and reliability analysis of fault tolerant system with service interruption and reboot

Due to widespread usage in many real time systems, reliability modeling and cost optimization of fault tolerance system have drawn attention of the practitioners. The fault tolerance in these systems can be provided by the support of maintenance and redundant components that help in smooth operation of the system in spite of failure of some active components. This investigation deals with the performance modeling of a fault-tolerant system consisting of a finite number of active (online) and standby components. During the switching from active to standby, the recovery procedure is performed, which may be imperfect. In case of imperfect recovery, the system reboot takes place. The maintenance of all the components is managed by a repairman (server) which is subject to failure. When the server is interrupted for rendering the service, functioning does not get stopped due to the system switch-over from perfect working to working breakdown mode. The system works even when the server is on working vacation and performs repair jobs of the failed components. The machine repair model based on Markovian process is developed to derive the transient probabilities and other performance indices of the fault tolerant system using Laplace transforms and matrix analytical method. Using the direct search strategy and particle swarm optimization, the cost-benefit analysis is done. The optimal design of the control parameters for the fault-tolerant system are presented by framing a cost-effective ratio function. The model is examined computationally by performing the numerical simulation and cost optimization.

Investigating the cost of mechanized unpaved road maintenance operations in Uganda

Force Account Mechanism (FAM) is the predominant road maintenance system in Uganda’s local government setup and a similar, though slightly different approach, is used in some large private sector agriculture plantations. With the Uganda Road Fund (URF) 2021/2022 annual report and previous research citing challenges in cost management and efficiency of the FAM method of road maintenance, it becomes paramount to analyse how FAM is implemented in government-led operations, in comparison to similar private sector approaches, while proposing possible solutions to these challenges. This research offered to analyse unpaved road maintenance cost drivers alongside providing a cost model solution to improve on cost prediction of the FAM system. Gulu District Local Government (DLG) and Kakira Sugar Limited (KSL) were selected as case study areas. Two descriptive research methods were used: observations and case study approach. The selected case study areas were accessible and reachable in terms of data. Control parameters affecting unpaved mechanized road maintenance were identified as machine repair costs, tool costs, labour costs, material costs, fuel costs and machine fuel costs. Unpaved mechanized road maintenance costs at KSL and Gulu DLG were computed as a cost/km ratio of 26,442,032Ugx/km (6,958.4USD/km) and 32,674,895Ugx/km (8,598.65USD/km) respectively. The Uganda National Roads Authority (UNRA) unpaved road maintenance costs were calculated as an average of 34,987,122.9Ugx/km (9,165USD/km) while the World Bank ROCKS database provided a comparable figure of 7,971USD/km (30,553,440.83Ugx/km). A USD to Ugx conversion rate of 3,800 was used. Two linear regression cost models with a 0.679 and 0.687 R2 value were computed, and these can be used in preliminary road maintenance cost prediction. The study recommends the need for an effective, digital road maintenance cost database system for mechanized unpaved road maintenance works, cost driver analytics and management, alongside improvement in aspects of maintenance processes at both the DLG and KSL. Further research can be conducted on equipment condition level prediction and analytics in the private sector and at the DLG.

The history of agricultural machinery repair system in Russia

The paper highlights the imperative for the maintenance and repair of agricultural machinery. (Research purpose) The research aims to undertake a retrospective analysis illuminating the evolution and establishment of the machine repair system. This analysis spans from the production of the inaugural Soviet tractor to the advancement and production of contemporary machinery and equipment. (Materials and methods) The paper analyses publications from different periods focused on the challenges surrounding the establishment of a centralized system for the repair and maintenance of machinery and equipment across all stages of agricultural production development. (Results and discussion). The paper sheds the light on the dynamics of tractor production in the early 1930s, detailing the transition from reliance on imports to the utilization of domestic agricultural machinery in the local market, alongside the phases involved in establishing a domestic repair service system. Furthermore, it explores the evolution of repair workshops at machinery technological stations from 1928 to 1957 and outlines the structuring of a repair depot within the enterprises of the All-Union Association «Soyuzselkhoztekhnika» between 1961 and 1990. Additionally, the paper delves into the analysis of repair strategies, ranging from individualized to in-line approaches. The paper underscores the pivotal role of academic and industrial science in equipping repair enterprises with essential technological documentation, repair equipment, and supplementary materials. It also highlights their contribution to the development of methodological support for maintenance and repair operations at the level of a centralized system. (Conclusions) The paper presents information on the research and design activities undertaken by specialized laboratories and departments within the All-Union Scientific Research Institute of Agricultural Mechanization VIM from 1930 to 1961. It acknowledges the significant contributions of scientists and experts in the domains of machine wear theory and the standardization of repair technologies. Furthermore, the paper emphasizes the critical influence of the State Union Scientific Research Technological Institute for the Repair and Operation of Tractors and Agricultural Machines GOSNITI between 1963 and 2013 on establishing a robust machinery repair and maintenance system. It outlines the potential and future directions for the evolution of a service system for agricultural machinery.

Cost optimal analysis for a differentiated vacation machining system with discouragement under the two threshold control policies

The present study explores the cost analysis for machine repair problem of queueing system using two-threshold control policies with discouragement and differentiated vacation. The way repairmen offer service has been established by two-threshold control policies based on queue size, with randomly distributed vacations of type A1 (full vacation) and type A2 (working vacation). Prior to the queue length being less than the lower threshold, both repairmen are on A1 type vacations. One repairman remains on A1 type vacation while the second repairman takes A2 type vacation if the queue length is in the intermediate range of the two thresholds. If the queue length is at or exceeds the upper threshold, both repairmen serve the queue to the best of their abilities. Meanwhile, during A1 and A2 types of vacations, failing machines exhibit impatience, which is a common occurrence in getting the service. It is supposed that vacation and repair time are exponentially distributed. The recursive method is utilized to calculate steady-state system probabilities. Furthermore, several metrics have been defined to measure the effectiveness of the system. A cost model is developed using system performance data for cost analysis. The Fibonacci search algorithm (FSA) and an artificial bee colony (ABC) are used to find the optimal value for the choice of variables with the lowest expected cost. A real-world instance demonstrating the implementation of the proposed model in practice will be shown at the end.

Current Issues of the Technical Support System for Complex Agricultural Machinery in the Agro-Industrial Complex

The basic principles are outlined and information is presented on the technical means essential for the system of maintenance and repair of machines in the agro-industrial complex, the mechanism of relations between manufacturers and consumers of technical means is described. Current issues of the subsystems of the repair and maintenance base in the engineering service of the agro-industrial complex, the main groups of repair and maintenance impacts on domestic agricultural machinery, etc. are considered.

The main stages of development of GOSNITI

The article presents the results of research scientists for 60 years of the State Scientifi c institutions of All-Russian Research Institute of Technology repair and maintenance of machines and tractors (GNU GOSNITI Ros-selhozakademii).

Performance Sensitivity Analysis for Machine Repair Problem with Two Failure Modes and Working Vacation

Production equipment is crucial to efficiency enhancement and product quality in the manufacturing industry. Repairman and removable standbys can be configured to support continuous production in order to minimize downtime and capacity loss associated with the malfunctioning of manufacturing equipment. Under these conditions, an idle repairman temporarily leaving the system to perform other tasks can undermine service performance. This paper presents a limited-capacity machine repair problem with standbys, two failure modes, and a working vacation policy. The steady-state system-size distribution is derived via the matrix analysis method and matrix decomposition. Based on steady-state probabilities, we derived closed-form formulations of several critical metrics for the assessment of system characteristics. Sensitivity analysis is performed to illustrate the effects of uncertainty in system parameters. Management implications are also addressed.

Skills and Techniques of Machine Repair Fitters

In this important understanding of machining, mechanical maintenance fitter occupies an important position. Machine repair fitters are mainly responsible for the processing and maintenance of various mechanical equipment, and use scientific control methods to restore mechanical properties. Therefore, we can see that the faults in machine maintenance need quick maintenance by fitters to solve various problems that often occur in machine maintenance. In this case, the fitter must master basic machine maintenance skills and use excellent information technology to assist in the installation of various machines. Therefore, this article gives a brief introduction to the machine fitters used for machine maintenance and shows how to increase their repair capacity to make machine maintenance more efficient. With the progress of scientific and the rapid increase in productivity, competition between enterprises is more and more intense. If enterprises want to maintain a high competitiveness and advantages, they need to focus on the research and development of core technology of their companies and improve core competitiveness. So in such a large background, many companies choose to focus on the development of their core business, and then they need other enterprises to complete their own non-core business resources. In such a development process, the logistics industry will gradually separated and then the third-party logistic enterprises show up.

Creation of innovative production systems in the machinery repair direction

This article examines the impact of digitization on machine repair production through the use of mathematical models. The main research tasks include analyzing recent studies and publications, identifying practical aspects of implementing innovative digital approaches in the machine repair production of Ukraine, developing mathematical models that describe the influence of «Industry 4.0» integration on machine repair processes and their research, and providing recommendations for machine repair enterprises to use innovative approaches to achieve stability in a changing market environment. The main focus is on analyzing the combination of «Industry 4.0» concepts and flexible production in machine repair processes. The research demonstrates significant potential for improving efficiency and productivity in this field with the implementation of innovative digital technologies. Based on the modeling, the possibility of assessing the impact of innovativeness on results in the context of machine repair has been considered. It is important to consider that this is only the most likely scenario of innovativeness, and actual results may depend on various factors, such as the amount of resources invested in research and implementation of innovations, as well as the level of competence of the personnel and other factors. Taking into account these additional factors allows understanding which combination of factors has the greatest impact on the results. Recommendations for further research include the use of machine learning algorithms and artificial intelligence to increase the accuracy and predictive capabilities of mathematical models. It is also recommended to explore the possibilities of integrating various digital technologies to achieve a synergy effect. For successful implementation of recommendations, it is important to systematically monitor their implementation and make necessary adjustments. Overall, this study opens up prospects for using digital technologies to improve the efficiency of machine repair production. Implementing the recommendations can lead to a significant increase in productivity and quality of processes, thereby enhancing the competitiveness of this market sector.

Technical support system for energy-installed agricultural equipment in the agricultural industry

Agricultural production in Russia solves the most important national problems - food security and import substitution. The conducted research substantiates the need to improve the engineering service of the agro-industrial complex through the introduction of modern innovative technologies. The article outlines the basic principles and technical means that determine the system of maintenance and repair of machines in the agro-industrial complex, as well as the mechanism of relations between manufacturers and consumers of technical means. Current issues of individual subsystems of the repair and maintenance base in the engineering service of the agro-industrial complex and the main groups of repair and maintenance impacts on domestic agricultural machinery were considered, and a relationship was established for foreign-made machines with all elements of maintenance, repair, modernization and disposal. Information is presented on depreciation rates and recommended distributions of the volume of repair and maintenance work by facility.

ANALYSIS OF WORK RISK LEVEL WITH SUITABILITY OF SAFETY SIGN AT PT. AIR MANCUR KARANGANYAR

Production activities that use machines pose a risk of danger to workers. The maintenance and repair of machines in the production process also has many potential hazards. So the purpose of this study was to analyze the effect of the level of occupational risk on the suitability of the safety sign at PT. Air Mancur Karanganyar. Hazard Identification Risk Assessment Determinant Control (HIRADC) method is a way of identifying hazards, risks and determining control of hazards. This study used a cross sectional quantitative, the sampling technique used was Porportionate Statified Random Sampling is if the population had members or elements that had proportional strata with the samples being 38 people. The inclusion criteria for this study were workers in engineering rooms, Solid External Medicines (OLP), and cosmetics at PT. Air Mancur Karanganyar. Data analysis of a spearmen correlation test. The results that there is a significant influence between the Level of Occupational Risk on the Compliance of the Safety Sign at PT. Air Mancur Karanganyar with a significance value of 0.012. The recommendations is are the placement of safety signs such as the Caution for Pinched Hands sign, routine socialization twice a week, and review HIRADC once a year