Regenerative Point Technique Research Articles

Optimizing System Efficiency and Reliability: Integrating Semi-Markov Processes and Regenerative Point Techniques for Maintenance Strategies in Plate Manufacturing

This paper offers a modeling methodology to evaluate similar systems’ performance and optimize system effectiveness with customized maintenance plans. This strategy, which combines regeneration point techniques with semi-Markov processes, is used to assess a plate manufacturing company’s system. Key insights are obtained using a thorough cost-benefit analysis that includes numerical analysis, graphical interpretations, and system efficacy indicators. The study clarifies the dynamics of the system’s reliability under different repair rates by showing an inverse relationship between Mean Time to System Failures (MTSF) and failure rate. Additionally, the analysis clarifies how profit is affected by failure rate, highlighting the necessity of efficient maintenance plans from an economic standpoint. This research highlights the growing significance of availability and dependability in technology-driven sectors and emphasizes the need for dependable systems. This paper makes a substantial contribution to the knowledge already available in the field of reliability engineering by providing a thorough framework that combines regeneration point approaches and semi-Markov processes. The metrics that are obtained offer a comprehensive understanding of the behavior of the system, which in turn helps industry practitioners make well-informed decisions.

Profit Comparison of Computer System with Hardware Redundancy Subject to Different Repair Activities

In this research paper, main concentrate of the authors on the profit comparison of computer system with hardware redundancy by introducing the concept of priority to software up-gradation, hardware preventive maintenance (PM) and hardware maximum repair time (MRT). The system fails independently from normal mode. All the repair activities such as hardware repair, software up-gradation, hardware preventive maintenance before failure and hardware replacement after maximum repair time are carried out by a single server immediately on need basis. All random variables are statistically independent. The negative exponential distribution is taken for the failure time of the component while the distributions of repair time, up-gradation time, preventive maintenance and replacement time are assumed arbitrary with different probability density functions. Semi-Markov process and regenerative point technique are used. The behaviour of profits of the system models have been examined for different parameters and costs.

Analysis of a Stochastic Model on Human Heart Considering its Failures and Treatments in Different Progression Stages

The goal of the present paper is to analyze the performance of a human heart considering failures of heart in different stages and their treatments. The aim of heart treatments is to progress through the stages or to slow down the progression from one stage to another. The artificial replacement of the heart is also possible these days. Keeping this in view, a stochastic model has been developed and investigated. The analysis of the model in terms of its performance measures is carried out on the basis of Markov process and regenerative point technique. Various conclusions are drawn on the basis of graphical study.. KEYWORDS :Human heart, Mean sojourn time, Mean time to system failure, Survivability, Regenerative point technique.

A two Identical Unit Cold Standby System with two Repairmen and Correlated Failure and Repair Times

The paper deals with the stochastic analysis of a two identical unit cold standby system model. As soon as a unit fails it is attended first by assistant repairman, who completes its repair to make it as good as new with fixed known probability p. Otherwise, with probability q( =1-p), the unit repaired by assistant repairman goes to expert repairman so as to make it as good as new. Both the repairmen are always available with the system and they work their jobs simultaneously. The failure time and repair time by assistant repairman are correlated random variables having their joint distribution as Bivariate exponential. Various measures of system effectiveness useful to system designers and operation managers are obtained by using regenerative point technique. The MTSF and steady state profit have also been studied through graphs in respect of parameter alpha for three different values of repair rate by expert repairman and two different values of correlation coefficient between failure and repair times and important conclusions are drawn.. KEYWORDS :Bivariate exponential distribution, Mean time to system failure (MTSF), Regenerative point, Laplace transform.

Performance Analysis of Feeding System in Sugar Mill with Consideration of Bagasse Jamming

Objectives: The sugar industry comprises various units, including feeding, crushing, evaporation, refining, and crystallization. The feeding system is the most crucial aspect of the sugar mill as the sugar-making process starts from here. So faults which occur here are divided into four categories minor, major, cease faults and walkout faults. This paper sets out to showcase a comprehensive analysis of the system's performance, availability, and profit. The study takes into account how minor, major, and cease faults can potentially impact the system's overall effectiveness. The findings of this research hold significant importance for sugar mills that prioritize optimal performance and profit. Methods: Primary data regarding various failures is collected from Ch. Devilal Co-Operative Sugar Mills Limited, Ahulana, Gohana. To find MTSF, Reliability, Availability, Profit etc., a mathematical model has been created. This model is based on the Semi-Markov process and Regenerative Point Technique and equations are drawn using exponential distribution and solved with Cremer’s rule and Laplace ­- Stieltjes transformation. Findings: A fault, Bagasse Jamming is considered a cease fault which occurs very frequently in the feeding system. Therefore, it is found that cease faults and major faults have more adverse impacts on the system's performance and availability than minor faults. MTSF, Availability and Profit are inversely proportional to these faults. When a major fault is 0.0035 and the cease fault is 0.0042, MTSF is nearly 100. So, to gain more profit we have to pay more attention to these faults. Novelty: The paper's results will aid in fault removal, increase availability, and optimize maintenance tactics in the sugar industry. Keywords: MTSF, Performance Analysis, Availability, Reliability, Minor, Major, Cease Faults

Optimizing Industrial Reliability: A Comparative Study of Hot and Cold Standby Configurations in Three-Unit Parallel Systems

This comparative research study explores the efficacy of two parallel systems, Model A employing a hot standby configuration and Model B utilizing a cold standby setup, each comprising three units operating based on demand. The investigation focuses on evaluating the reliability and cost-effectiveness of these systems, employing metrics such as Mean Time to System Failure, availability at full and reduced capacity, repairer busy periods, downtime, and profit analysis using Semi-Markov and regenerative point techniques. Results reveal that Model B (cold standby) outperforms Model A (hot standby) across multiple parameters, including Mean Time to System Failure, availability, repairer busy periods, downtime, and profitability. Specifically, Model B demonstrates higher values for Mean Time to System Failure, Availability at full and reduced capacity, Busy period for repairmen, and Profit in Rs. Consequently, it is inferred that Model B proves to be more reliable and efficient than Model A. These findings underscore the potential advantages of employing cold standby configurations in similar machinery setups, offering insights to enhance system performance and minimize downtime, thus suggesting avenues for optimizing cold standby parallel systems based on the study's outcomes.

Analyzing the Effects of Repairman Failure in Stochastic Models of Non-Identical Redundant Systems

A stochastic analysis is presented here of a repairable system containing two non-identical units, one of which is a duplicate and the other is a main unit. When the units are operative, they have a direct complete failure. During his work with the main unit, a single repairman may encounter problems that may cause his work to fail. During the repair of the duplicate unit, the repairman encounters no problems. Duplicate units receive priority for repair and operation over primary units. After receiving treatment, the repairman can perform his duties with full efficiency. For failure rates of the units, negative exponential distributions were used, while for repair and treatment rates, arbitrary distributions were used. The semi-Markov process and regenerative point technique studied various possible transition states. The reliability characteristics of the system model have been examined numerically and graphically for various parameter values. The profit of the system has also been analyzed for some fixed values of repair and other maintenance costs.

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.

Novel Analysis between Two-Unit Hot and Cold Standby Redundant Systems with Varied Demand

Decisive applications, such as control systems and aerial navigation, require a standby system to meet stringent safety, availability, and reliability. The paper evaluates the availability, reliability, and other measures of system effectiveness for two stochastic models in a symmetrical way with varying demand: Model 1 (a two-unit cold standby system) and Model 2 (a two-unit hot standby system). In Model 1, the standby unit needs to be activated before it may begin to function; in Model 2, the standby unit is always operational unless it fails. The current study demonstrates that the hot standby system is more expensive than the cold standby system under two circumstances: a decrease in demand or the hot standby unit’s failure rate exceeding a predetermined threshold. The cold standby system’s activation time is at most a certain threshold, and turning both units on at once is necessary to handle the increasing demand. In that case, the hot standby will be more expensive than the cold standby system. The authors used semi-Markov and regenerative point techniques to analyze both models. They collected actual data from a cable manufacturing plant to illustrate the findings. Plotting several graphs and obtaining cut-off points make it easier to choose the standby to employ.

Reliability modelling of a parallel-cold standby system with proviso of repair priority

Here, reliability modelling of a parallel cold standby system of four units has been done with the provision of priority to repair. Initially, the system has two operative units in parallel mode (called phase-I units) and the other two units are taken as spare in the cold standby (called phase-II units). The phase-I units (main units) are assumed as more efficient than that of the phase-II units (duplicate units). The units in phase-I and phase-II are non-identical but they are identical within the phases. The units in phase-II work simultaneously at the failure of units of phase-I. The priority to repair the units of phase-II has been given over the repair of the units of the phase-I. However, no priority is given for operation of the units of both phases. The repair activities are handled by a single server who attends the system immediately when required. The failure rate of the units follows negative exponential distribution while the distribution for repair time of the phase-I and phase-II units is assumed as arbitrary. Some significant reliability characteristics such as mean sojourn times (MST), transition probabilities, mean time to system failures (MTSF), availability, expected number of repairs (for both phase-I and phase-II units), busy period of the server, expected number of visits of the server and finally the profit function are obtained in steady state by making use of well-known semi-Markov process (SMP) and regenerative point technique (RPT). The graphical representation of these reliability characteristics has been made for arbitrary values of the rates associated with failure and repair times. The application of the present study can be seen in the power distribution system.

Stochastic modelling of a system having two non-identical class of units

This paper deals with the study of stochastic modelling of a system having two non-identical class of units. The whole system consists of two class L1 and L2 respectively. First class consists only one unit where as second class having two identical units. The whole system is used to process the jobs. Jobs are first processes on L1 unit (class one) and then goes to L2 unit (second class). All the failure time distribution are taken as arbitrarily distributed. Using regenerative point technique, various reliability characteristics of interest to the system managers have been evaluated. Finally, some graphs are also plotted in order to highlight the important results.

Reliability Modeling of a Food Industrial System with two Types of Repair Persons wherein Demand is Season Dependent

The present study pertains to developing a reliability model concerning a food industrial system that runs throughout the month except for Sundays. There are two types of repair persons engaged with the system, one known as operator while another is fitter. The operator is responsible for minor repairs, while the fitter is responsible for major repairs. It is also noticed that the operator is the first person who attends the failed unit in case of a major failure. If the operator is found incapable of repairing the unit within some patience time, then the fitter is called. While gathering the actual month-wise data of the plant, two types of seasons, namely normal and festival seasons, have been recorded. The festival season is from July to November, while the normal season is from December to June, based on consumer demand. During the months of the normal season, the system is shut down for a few days as the demand gets accomplished before the month ends. However, during the festival season, the system has to be kept operational throughout the month to fulfill the high demand for the product. The semi-Markov process and regenerative point technique are used to assess the reliability measures, namely mean time to system failure (MTSF), system availability in both seasons, expected busy period of the repair persons, and expected downtime of the system. The overall profitability of the system is also demonstrated by Graphical interpretation.

Reliability analysis of captive power plant system where the working of standby unit depends on connecting unit

Captive power plants usually operate parallel to the gridline to overcome the losses associated with power failures. While the connectivity of the power plant and gridline highly depends on the functioning of the electrical breaker. This study reveals the importance of connecting device breakers in a captive power plant to operate the system at full or reduced capacity and safer it from reverse feeding. Using semi-Markov processes reliability model is developed for steam turbine generators interconnected with gridline by an electric breaker. The expressions are formed for reliability measures like mean time to system failure, availability, busy period, and profit using regenerative point techniques. Also, these measures are evaluated numerically using an actual dataset belonging to a captive power plant. Graphical plotting shows a decline in profit with increasing the failure rates of turbine generators, gridline, and working probability of breaker. The revenue per unit uptime of the system is forecasted to get productive profit with different failure rates of the power generator.

An Analytical Study of Powder Plant System

Objective: An investigation was carried out for the seasonal functioning of the powder system in a dairy plant. The paper evaluates the reliability measures of the system in two seasons, which is based on the real-life case study of the system. Solutions are presented numerically as well as graphically. Methods: SemiMarkov process and the regenerative point technique have been used for the system analysis wherein the transition and steady-state probabilities are obtained. Findings: Numerical results have been found using MATLAB. Code Blocks, excel have been used for the graphical representation. Expressions for a variety of system effectiveness which include MTSF, long-term availability in two seasons, busy period for repair and maintenance in both the seasons, the expected number of repairs and maintenances, and at last the profit generated by the system. A specific case is considered for graphical analysis. Novelty: In the previous research paper, reliability modeling of the system was done without describing the seasonal effect; in this paper, reliability analysis is carried out of working of the powder system seasonally. The originality of this research lies in its way of calculating the expressions individually with respect to the seasons, giving a better and more accurate view of the system analysis. Applications: The model obtained from this research will benefit the engineers in understanding the systems having similar working conditions; also, the existing model will help in improving system performance in the powder system, attained from the Verka Milk Plant. Keywords: Powder plant; seasons; semiMarkov process; regenerative point technique; reliability measures

Reliability Modeling of a System With One Main Unit and Two Associate Units Along With Sub-Unit

In this paper, we develop a stochastic reliability model of a one-unit main system with two associate units. Each associate unit also has one sub-unit. Sub-units depend upon Associate units and associate units depend upon the main unit. The system will be operable when the main unit and at least one associate unit with sub-unit are in operation. As soon as a job arrives, all the units work with load. It is assumed that only one job is taken for processing at a time. There is a single repairman who repairs the failed units on a first-come-first-served basis. Various reliability characteristics of the system effectiveness will be obtained by using semi-Markov processes and regenerative point techniques.

STOCHASTIC MODELING AND SENSITIVITY ANALYSIS OF AN INTEGRATED HARDWARE-SOFTWARE SYSTEM SUBJECT TO DIFFERENT WEATHER CONDITIONS

The current study covenants with stochastic investigation of an integrated hardware-software system considering hardware failure, software up-gradation upon failure, precautionary maintenance (PM) after a pre-determined process time, maximum repair time of hardware and different weather conditions. All time dependent indiscriminate variables are arbitrarily dispersed. Some important reliability measures like MTSF, availability and revenue of the system are obtained by using well established techniques semi-Markov process. Regenerative point technique has also been taken into consideration during model development. Sensitivity analysis of these measures is also performed. Finally, empirical analysis is done to demonstrate the results for a specific case. To climax the significance of the study, graphs of MTSF, availability, profit and sensitivity are also depicted.

Reliability Analysis of Two Unit Standby Model with Controlled and Uncontrolled Failure of Unit and Replacement Facility Available in the System

Planning a highly reliable and efficient system has always been a primary interest for reliability engineers by devising the powerful design strategy and employing effective repair and replacement policy. Keeping in view this, the basic aim of this paper is to analyze the reliability of a system which comprised of two units A and B in which unit A is functional and B is held standby. Unit A after failure may be controlled or uncontrolled. The failed unit undergoes for repair in the controlled unit. If the repair of a unit is not controlled then it is replaced by a new one. Upon the breakdown of operational unit A, unit B come becomes active instantaneously. Unit B after failure is repaired by regular repairmen. System failure takes place when both the units quit serving. The unit serves as good as a fresh after preventive repair and replacement policy. The regenerative point technique has been used to obtain the expression for several reliability measures. Finally, the graphical behavior of MTSF and profit of the present model has been observed for arbitrary values of parameters and costs.

Reliability modeling and performance evaluation of solar photovoltaic system using Gumbel–Hougaard family copula

PurposeSolar photovoltaic (PV) is commonly used as a renewable energy source to provide electrical power to customers. This research establishes a method for testing the performance reliability of large grid-connected PV power systems. Solar PV can turn unrestricted amounts of sunlight into energy without releasing carbon dioxide or other contaminants into the atmosphere. Because of these advantages, large-scale solar PV generation has been increasingly incorporated into power grids to meet energy demand. The capability of the installation and the position of the PV are the most important considerations for a utility company when installing solar PV generation in their system. Because of the unpredictability of sunlight, the amount of solar penetration in a device is generally restricted by reliability constraints. PV power systems are made up of five PV modules, with three of them needing to be operational at the same time. In other words, three out of five. Then there is a charge controller and a battery bank with three batteries, two of which must be consecutively be in operation. i.e. two out of three. Inverter and two distributors, all of which were involved at the same time. i.e. two out of two. In order to evaluate real-world grid-connected PV networks, state enumeration is used. To measure the reliability of PV systems, a collection of reliability indices has been created. Furthermore, detailed sensitivity tests are carried out to examine the effect of various factors on the efficiency of PV power systems. Every module's test results on a realistic 10-kW PV system. To see how the model works in practice, many scenarios are considered. Tables and graphs are used to show the findings.Design/methodology/approachThe system of first-order differential equations is formulated and solved using Laplace transforms using regenerative point techniques. Several scenarios were examined to determine the impact of the model under consideration. The calculations were done with Maple 13 software.FindingsThe authors get availability, reliability, mean time to failure (MTTF), MTTF sensitivity and gain feature in this research. To measure the reliability of PV systems, a collection of reliability indices has been created. Furthermore, detailed sensitivity tests are carried out to examine the effect of various factors on the efficiency of PV power systems.Originality/valueThis is the authors' original copy of the paper. Because of the importance of the study, the references are well-cited. Nothing from any previously published articles or textbooks has been withdrawn.

Comparison of fuzzy semi-Markov models for one unit with mixed standby units with and without preventive maintenance using regenerative point method

This paper introduced a study for a new system that consists of one unit with mixed standby units. The mathematical model for the system is constructed using semi-Markov model with regenerative point technique in two cases: the first case when there is preventive maintenance provided to the main unit and the second case when there is no preventive maintenance in the system. Life and repair times of the units in the system are assumed to be generally distributed with fuzzy parameters defined by the bell-shaped membership function. A Numerical application is introduced to compare the performance of the system in the two cases.

Cost Benefit Analysis of Three Non-Identical Machine Model with Priority in Operation and Repair

The paper proposes a new real life model and the main aim is to examine the cost benefit analysis of Textile Industry model subject to different failure and repair strategies. The reliability model comprises of three units i,e Spinning machine (S), Weaving machine (W), Colouring and Finishing machine(Cf). The working principal of the model starts with spinning machine (S) where in unit S is in operative state while as weaving machine, Colouring and Finishing machine are in ideal state. Complete failure of system is observed when all three units of system i.e. S,W and Cf are in down state. Repairperson is always available to carry out the repair activities in the system in which first priority in repair is given to Colouring and Finishing machine followed by Spinning and weaving machine. The proposed model attempts to maximize the reliability of a real life system. Reliability measures such as Mean Sojourn time, Mean time to system failure, Profit analysis of system are examined to define the performance of the reliability characteristics. For concluding the study of such model, different stochastic measures are analyzed in steady state using regenerative point technique. The tables are prepared for arbitrary values of the parameters to show the performance of some important reliability measures and to check the efficiency of the model under such situations.