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Article
Publication date: 8 July 2019

Abdul Kareem Lado and V.V. Singh

The purpose of this paper is to covenant with the cost assessment of a complex repairable system, consisting of two subsystems (Subsystem 1 and Subsystem 2) connected in…

Abstract

Purpose

The purpose of this paper is to covenant with the cost assessment of a complex repairable system, consisting of two subsystems (Subsystem 1 and Subsystem 2) connected in series configuration and being operated by a human operator. Each subsystem has two identical units in parallel configuration and has different types of failure and two types of repairs (general repair and copula repair). Through the transition diagram, the system of first-order partial differential equations is derived and solved using a supplementary variable technique, Laplace transforms. All failures are assumed to follow exponential distribution, whereas repairs follow two types of distributions that are general and Gumbel–Hougaard family copula. In this paper, explicit expressions for reliability, availability, mean time to failure (MTTF) and cost analysis functions have been obtained. In this paper, two types of repairs (copula repair and general repair) have been studied, and it has been concluded that copula repair is more reliable as compared to general repair. Some computations are taken as particular case by evaluating: reliability, availability, MTTF and cost analysis, so as to capture the effect of both failure and repair rates to reliability measures. The results have been shown in tables and graphs. The convincing part has been discussed in last section of this study.

Design/methodology/approach

This paper is focused on the cost assessment of a system consisting two subsystem series configuration. Each subsystem has two identical units in parallel configuration. The performance of the system has been analyzed by supplementary variable techniques and Laplace transforms. Various measures of the reliability have been discussed by evaluations. Software called Maple 13 is used for computations.

Findings

In this research paper, the authors have evaluated the operational cost and incurred profit of the system together with other reliability measures for various situations and different types of failures and two types of repairs using Gumbel–Hougaard family copula distribution.

Research limitations/implications

The present research focuses on the series and parallel configured complex systems that is used everywhere in industry and other sectors. The authors main aim is to claim that repair through the joint probability distribution copula is far better than general repair. Copula repair for a completely failed system is more beneficial for industrial system operations that will increase profit to the industrial sector.

Practical implications

The authors have observed that when repair follows general distribution the values of reliability obtained of the system are less compared to the those obtained when the authors apply copula repair, a joint probability distribution. It is a clear implication for industrial sector and organization to use the policy for a better generate revenue.

Social implications

According to the best of authors’ knowledge, there is no social implication as this study is meant for reliability section. The study in management and case study matters is considered to have social implication.

Originality/value

This research is the original work of authors. Nothing has been copied from any paper or book. The references are cited according to the relevance of study.

Details

International Journal of Quality & Reliability Management, vol. 36 no. 10
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 25 May 2010

Mangey Ram and S.B. Singh

The main aim of this paper is to improve reliability characteristics namely availability, mean time to failure (MTTF), and expected profit of a complex system.

Abstract

Purpose

The main aim of this paper is to improve reliability characteristics namely availability, mean time to failure (MTTF), and expected profit of a complex system.

Design/methodology/approach

The paper discusses the availability of a complex system, which consists of two independent repairable subsystems A and B in (1‐out‐of‐2: F) and (1‐out‐of‐n: F) arrangement respectively. Subsystem A has two identical units arranged in parallel redundancy (1‐out‐of‐2: G), subsystem B has n units in series (1‐out‐of‐n: F) with two types of failure, namely, partial and catastrophic. Except at two transitions where there are two types of repair namely exponential and general possible. The failure and repair time for both subsystems follow exponential and general distributions respectively. The model is analysed under “preemptive‐repeat repair discipline” where A is a priority and B is non‐priority.

Findings

By employing supplementary variable technique, Laplace transformation and Gumbel‐Hougaard family copula various transition state probabilities, availability, MTTF and cost analysis (expected profit) are obtained along with steady‐state behaviour of the system. Inversions have also been carried out so as to obtain time dependent probabilities, which determine availability of the system at any instant.

Originality/value

This paper, through a systematic view, presents a mathematical model of a complex system from which the reliability characteristics namely availability, MTTF, and expected profit of a complex system can be improved.

Details

International Journal of Quality & Reliability Management, vol. 27 no. 5
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 5 January 2015

D. K. Rawal, Mangey Ram and V. V. Singh

– The purpose of this paper is to find the reliability measures of Linux operating system connected in local area network (LAN).

Abstract

Purpose

The purpose of this paper is to find the reliability measures of Linux operating system connected in local area network (LAN).

Design/methodology/approach

The system has two different topologies, i.e. star topology (subsystem-1) and bus topology (subsystem-2), are placed at two different places, and connected to a server through a hub. Both the topologies have n clients. The system has partial failure and complete failure. The partial failure is of two type’s namely minor partial and major partial. The minor partial failure degrades the system whereas the major partial failure brings the system to a break down mode. The system can completely fail due to failure of server hacking and blocking.

Findings

By using supplementary variable technique and Laplace transformation, by taking different types of failure and two types of repairs the availability, non-availability, mean time to failure and cost analysis (expected profit) of the design system have been obtained.

Originality/value

In this research, a mathematical model of Linux operating system has been discussed from which one can check the behavioral analysis of the designed system.

Details

International Journal of Quality & Reliability Management, vol. 32 no. 1
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 4 March 2020

Nisha Nautiyal, S.B. Singh and Soni Bisht

The present paper focuses on the evaluation of reliability and its characteristics (Mean time to failure and Sensitivity) of a k-out-of-n network.

Abstract

Purpose

The present paper focuses on the evaluation of reliability and its characteristics (Mean time to failure and Sensitivity) of a k-out-of-n network.

Design/methodology/approach

The minimal cuts of the network have been evaluated for different nodes in this paper, using an algorithm. With the help of these cuts, reliability and its characteristics are obtained using Gumbel–Hougaard family of the copula.

Findings

The present paper proposes to compute the reliability and its measures of the k-out-of-n network using the minimal cuts and copula methodology. The completely failed nodes of the network have been repaired using Gumbel–Hougaard family of the copula.

Originality/value

In this paper, the reliability of a k-out-of-n network has been evaluated by first calculating k-out-of-n minimal cuts, and the failed nodes have also been repaired using Gumbel–Hougaard family of the copula, unlike as done in the past.

Details

International Journal of Quality & Reliability Management, vol. 37 no. 4
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 12 February 2019

Neelam Chantola and S.B. Singh

The purpose of this paper is to study various reliability measures like reliability, mean time to failure (MTTF) and sensitivity of transformer including different…

Abstract

Purpose

The purpose of this paper is to study various reliability measures like reliability, mean time to failure (MTTF) and sensitivity of transformer including different parameters of insulating oil/paper as health index.

Design/methodology/approach

The reliability characteristics of transformer incorporating different parameters of insulating oil as well as paper have been evaluated using Markov process incorporating Gumbel–Hougaard copula, Laplace transforms and supplementary variable technique. The parameters taken into consideration are breakdown voltage (BDV) and moisture content (MC) of both insulating oil and paper, and other parameters considered are interfacial tension (IFT), dissipation factor (DF), degree of polymerization (DOP) and furanic content (FC) for insulating oil and paper, respectively. By probability consideration and continuity influence, difference-differential equations have been obtained for the considered model.

Findings

Transition state probabilities, reliability, MTTF and sensitivity of the transformer corresponding to different parameters of insulating oil and paper have been evaluated with the help of aforementioned technique. Variations of reliability with respect to time along with the variations of MTTF and sensitivity have also been examined. Remarkable points during the study have also been pointed out.

Originality/value

Reliability characteristics of the transformer have been evaluated including two parameters: insulating oil and paper with the help of supplementary variable technique, considering two different types of repairs incorporating Gumbel–Hougaard family of copula unlike done earlier. Reliability, MTTF and sensitivity of transformer have been analyzed considering the parameters: BDV, MC, IFT and FC of insulating oil, and BDV, MC, DOP, DF of insulating paper.

Details

International Journal of Quality & Reliability Management, vol. 36 no. 6
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 3 January 2017

Nupur Goyal and Mangey Ram

The purpose of this paper is to analyse the performance of a wind electric generating power plant through the study of reliability measures. The enhancement of the…

Abstract

Purpose

The purpose of this paper is to analyse the performance of a wind electric generating power plant through the study of reliability measures. The enhancement of the performance of the wind power plant using various approaches is also an objective of this paper.

Design/methodology/approach

This paper describes two models of a wind electric generating power plant using the Markov process and supplementary variable technique and solved with the help of Laplace transformation. The first model has been analyzed without fault coverage and Gumbel-Hougaard family of copula, while the second model of the wind power plant employs fault coverage and Gumbel-Hougaard family of copula which are used to enhance the performance. The proposed methodology is then illustrated in detail considering numerical examples.

Findings

Numerous reliability characteristics such as availability, reliability and mean time to failure to examine the performance of the wind power plant have been investigated. Through the comparative study of both the models, the authors concluded that the plant can generate electricity over long periods of time by covering more and more detected faults, which is made possible with two types of repair facility.

Originality/value

In this work, the authors have developed a mathematical model based on a wind electric generating power plant. This work incorporates not only the component failures that stop or degrade the working of the plant but also deals with the catastrophic and repair strategy of the plant.

Details

International Journal of Quality & Reliability Management, vol. 34 no. 1
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 6 April 2021

Abdulkareem Lado Ismail, Sanusi Abdullahi and Ibrahim Yusuf

This study deals with the reliability analysis of a hybrid series–parallel system consisting of two subsystems A and B with two human operators. Subsystem A has two units…

Abstract

Purpose

This study deals with the reliability analysis of a hybrid series–parallel system consisting of two subsystems A and B with two human operators. Subsystem A has two units in active parallel while subsystem B consists of two-out-of-four units. Both units have exponential failure and repair time. The system under consideration has two states: partial failure state and complete failure state. The mathematical equations associated with the transition diagram have been formulated using regenerative point techniques. The system is analysed using Laplace transforms to solve the mathematical equations. Some important measures of reliability such as availability of system, reliability of the system, mean time to failure (MTTF), sensitivity for MTTF and cost analysis have been discussed. Some particular cases have also been derived and examined to see the practical effect of the model. The computed results are demonstrated by tables and graphs. Furthermore, the results of the designed model are beneficial for system engineers and designers, reliability and maintenance managers.

Design/methodology/approach

This paper considered a hybrid series–parallel system consisting of two subsystems A and B with two human operators. The performance of the system is studied using the supplementary variable technique and Laplace transforms. The various measures of reliability such as availability, reliability, mean time to system failure (MTSF), sensitivity for MTTF and cost analysis have been computed for various values of failure and repair rates. Maple 13 software has been used for computations.

Findings

In this research paper, the authors have computed various measures of reliability such as availability, reliability, MTSF, sensitivity for MTTF and cost analysis for various values of failure and repair rates and find that failure due to human operators are more responsible for successful operation of the system and also regular repair should be invoked to improve system performance.

Originality/value

This research paper is the original work of authors. The references are well cited based on the importance of study. Nothing has been detached from any research paper or books.

Details

International Journal of Quality & Reliability Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 5 June 2017

Anuj Kumar, Sangeeta Pant and S.B. Singh

The purpose of this paper is to evaluate various reliability measures like availability, reliability, mean time to failure and profit function.

Abstract

Purpose

The purpose of this paper is to evaluate various reliability measures like availability, reliability, mean time to failure and profit function.

Design/methodology/approach

The authors present a novel method for availability analysis of an engineering system incorporating waiting time to repair. The considered system consists of two subsystems, namely, A and B connected in series. The subsystem B has two identical units in standby arrangement. Each unit of the subsystem has two modes, i.e. normal efficiency or failed. The two standby units of the subsystem B are connected by an imperfect switching. The system is analyzed by supplementary variable technique, Laplace transformation and Gumbel-Hougaard family of copula.

Findings

Numerical examples with a way to highlight the important results have been appended at last. Numerical calculation shows that availability and reliability of the system is decreasing with respect to time when failure rates are fixed at different values. Finally, cost analysis of system reveals that the expected profit decreases with increase in service cost.

Originality/value

This paper presents a mathematical model in which an important aspect of switching has been taken into consideration, which is consistent with actual failures of switching by assuming two different types of failure between adjacent transition. It is evaluated with the help of the Gumbel-Hougaard family of copula.

Details

International Journal of Quality & Reliability Management, vol. 34 no. 6
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 2 April 2021

V. V. Singh, Abubakkar Idris Mohhammad, Kabiru Hamisu Ibrahim and Ibrahim Yusuf

This paper analyzed a complex system consisting n-identical units under a k-out-of-n: G; configuration via a new method which has not been studied by previous researchers…

Abstract

Purpose

This paper analyzed a complex system consisting n-identical units under a k-out-of-n: G; configuration via a new method which has not been studied by previous researchers. The computed results are more supportable for repairable system performability analysis.

Design/methodology/approach

In this paper, the authors have analyzed a complex system consisting n-identical units under a k-out-of-n: G; configuration via a new method which has not been studied by previous researchers. The supplementary variable technique has employed for analyzing the performance of the system.

Findings

Reliability measures have been computed for different types of configuration. It generalized the results for purely series and purely parallel configurations.

Research limitations/implications

This research may be beneficial for industrial system performances whereas a k-out-of-n-type configuration exists.

Practical implications

Not sure as it is a theoretical assessment.

Social implications

This research may not have social implications.

Originality/value

This work is the sole work of authors that have not been communicated to any other journal before.

Details

International Journal of Quality & Reliability Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 7 March 2016

Mangey Ram and Kuldeep Nagiya

– The purpose of this paper is to evaluate performance of mobile communication system with reliability measures.

Abstract

Purpose

The purpose of this paper is to evaluate performance of mobile communication system with reliability measures.

Design/methodology/approach

The mobile communication system consists of a mobile station (MS), base transceiver station (BTS), base station controller (BSC) and the mobile switching center. The MS is connected to BTS, BTS is connected to BSC and BSC is connected with the mobile switching system. With the help of these stations working, the authors have developed a mathematical model using Markovian approach.

Findings

Using the supplementary variable technique, the Laplace transformations and Markov process theory, the reliability indices of the mobile communication system are determined.

Originality/value

In the present work, the authors have developed a mathematical model based on a mobile communication system.

Details

International Journal of Quality & Reliability Management, vol. 33 no. 3
Type: Research Article
ISSN: 0265-671X

Keywords

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