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1 – 10 of 299
Article
Publication date: 28 March 2008

Nabil Nahas, Mustapha Nourelfath and Daoud Ait‐Kadi

The purpose of this paper is to extend the optimal design problem of series manufacturing production lines to series‐parallel lines, where redundant machines and in‐process…

Abstract

Purpose

The purpose of this paper is to extend the optimal design problem of series manufacturing production lines to series‐parallel lines, where redundant machines and in‐process buffers are both included to achieve a greater production rate. The objective is to maximize production rate subject to a total cost constraint.

Design/methodology/approach

An analytical method is proposed to evaluate the production rate, and an ant colony approach is developed to solve the problem. To estimate series‐parallel production line performance, each component (i.e. each set of parallel machines) of the original production line is approximated as a single unreliable machine. To determine the steady state behaviour of the resulting non‐homogeneous production line, it is first transformed into an approximately equivalent homogeneous line. Then, the well‐known Dallery‐David‐Xie algorithm (DDX) is used to solve the decomposition equations of the resulting (homogenous) line. The optimal design problem is formulated as a combinatorial optimisation one where the decision variables are buffers and types of machines, as well as the number of redundant machines. The effectiveness of the ant colony system approach is illustrated through numerical examples.

Findings

Simulation results show that the analytical approximation used to estimate series‐parallel production lines is very accurate. It has been found also that ant colonies can be extended to deal with the series‐parallel extension to determine near‐optimal or optimal solutions in a reasonable amount of time.

Practical implications

The model and the solution approach developed can be applied for optimal design of several industrial systems such as manufacturing lines and power production systems.

Originality/value

The paper presents an approach for the optimal design problem of series‐parallel manufacturing production lines.

Details

Journal of Quality in Maintenance Engineering, vol. 14 no. 1
Type: Research Article
ISSN: 1355-2511

Keywords

Article
Publication date: 13 May 2021

Aiping Jiang, Zhenni Huang, Jiahui Xu and Xuemin Xu

The purpose of this paper is to propose a condition-based opportunistic maintenance policy considering economic dependence for a series–parallel hybrid system with a K-out-of-N

Abstract

Purpose

The purpose of this paper is to propose a condition-based opportunistic maintenance policy considering economic dependence for a series–parallel hybrid system with a K-out-of-N redundant structure, where a single component in series is denoted as subsystem1, and K-out-of-N redundant structure is denoted as subsystem2.

Design/methodology/approach

Based on the theory of Residual Useful Life (RUL), inspection points are determined, and then different maintenance actions are adopted in the purpose of minimizing the cost rate. Both perfect and imperfect maintenance actions are carried out for subsystem1. More significantly, regarding economic dependence, condition-based opportunistic maintenance is designed for the series–parallel hybrid system: preemptive maintenance for subsystem1, and both preemptive and postponed maintenance for subsystem2.

Findings

The sensitivity analysis indicates that the proposed policy outperforms two classical maintenance policies, incurring the lowest total cost rate under the context of both heterogeneous and quasi-homogeneous K-out-of-N subsystems.

Practical implications

This model can be applied in series–parallel systems with redundant structures that are widely used in power transmission systems in electric power plants, manufacturing systems in textile factories and sewerage systems. Considering inconvenience and high cost incurred in the inspection of hybrid systems, this model helps production managers better maintain these systems.

Originality/value

In maintenance literature, much attention has been received in repairing strategies on hybrid systems with economic dependence considering preemptive maintenance. Limited work has considered postponed maintenance. However, this paper uses both condition-based preemptive and postponed maintenance on the issue of economic dependence bringing opportunities for grouping maintenance activities for a series–parallel hybrid system.

Details

Journal of Quality in Maintenance Engineering, vol. 28 no. 3
Type: Research Article
ISSN: 1355-2511

Keywords

Article
Publication date: 1 September 2002

Toshio Nakagawa and Qian Cun Hua

This paper considers a series‐parallel and a parallel‐series system, and investigates theoretically their fundamental characteristics: it is shown that the reliability of the…

431

Abstract

This paper considers a series‐parallel and a parallel‐series system, and investigates theoretically their fundamental characteristics: it is shown that the reliability of the series‐parallel system with the same number of series and parallel tends to one as its number goes to infinity. It would be of great interest that the golden ratio plays a role in analyzing two systems. Further, an optimal number of units for a series‐parallel system with complexity is derived.

Details

Journal of Quality in Maintenance Engineering, vol. 8 no. 3
Type: Research Article
ISSN: 1355-2511

Keywords

Article
Publication date: 1 September 2005

Neeraj Kumar Goyal, Ravindra Babu Misra and Sanjay Kumar Chaturvedi

This paper proposes a new approach source node exclusion method (SNEM) to evaluate terminal pair reliability of complex communication networks.

Abstract

Purpose

This paper proposes a new approach source node exclusion method (SNEM) to evaluate terminal pair reliability of complex communication networks.

Design/methodology/approach

The proposed approach breaks a non‐series‐parallel network to obtain its sub‐networks by excluding the source node from rest of the network. The reliabilities of these sub‐networks are thereafter computed by first applying the series‐parallel‐reductions to it and if any sub‐network results into another non‐series‐parallel network then it is solved by the recursive application of SNEM.

Findings

The proposed method has been applied on a variety of network and found to be quite simple, robust, and fast for terminal pair reliability evaluation of large and complex networks.

Practical implications

The proposed approach is quite simple in application and applicable to any general networks, i.e. directed and undirected. The method does not require any prior information such as path (or cut) sets of the network and their pre‐processing thereafter or perform complex tests on networks to match a predefined criterion.

Originality/value

The proposed approach provides an easy to develop and easy to use tool to determine terminal pair reliability of a communication network. The approach is particularly useful for communication network designer and analysts.

Details

Journal of Quality in Maintenance Engineering, vol. 11 no. 3
Type: Research Article
ISSN: 1355-2511

Keywords

Article
Publication date: 5 October 2012

Stephen Twum, Elaine Aspinwall and Jörg Fliege

Reliability is a major quality characteristic which has grown in importance as products/systems have become ever more sophisticated. Neglecting it could spell great losses in…

Abstract

Purpose

Reliability is a major quality characteristic which has grown in importance as products/systems have become ever more sophisticated. Neglecting it could spell great losses in terms of patronage, revenue, and even lives. The purpose of this paper is to present a multi‐criteria optimisation model and methodology for the Pareto optimal assignment of reliability to the components of a series‐parallel system in order to maximise its reliability.

Design/methodology/approach

The subsystems' reliabilities are maximised independently but simultaneously in order to maximise the overall system reliability, while a penalty function modelling cost of reliability improvement is minimised. The resultant continuous and nonlinear optimisation problem is scalarised by a convex combination of the criteria and the MATLAB Optimisation Toolbox is used to generate the solutions.

Findings

The results for an illustrative example problem extracted from the literature show that: higher reliabilities could be assigned to the components, in order to achieve or exceed target system reliability; cost increased sharply with slight improvements in the component reliabilities, and the model was stable under the weighting scheme used.

Originality/value

The novelty of this work is in: the multi‐criteria optimisation view taken of the design problem; the focus on the subsystems' reliabilities and cost as the criteria to be optimised; the use of the two aforementioned qualities for the purpose of Pareto assignment of component reliabilities in a system's design; and the use of the model and methodology in the context of series‐parallel systems.

Details

International Journal of Quality & Reliability Management, vol. 29 no. 9
Type: Research Article
ISSN: 0265-671X

Keywords

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 in…

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. 39 no. 1
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 1 July 2000

Wu Xuemou, Pan Jinghong and Heng Pheng‐Ann

The framework, panorama, related applications and development of pansystems thinking are introduced and some problems concerning generalized systems, derivatives, symmetry and…

Abstract

The framework, panorama, related applications and development of pansystems thinking are introduced and some problems concerning generalized systems, derivatives, symmetry and quantification are investigated, a sort of difference‐identity theory within the framework of pansystems thinking is cultivated, and a new type of clustering method with many intertransformations among some important pansystems concepts is presented. Related contents include: pansystems combination of mathematics, systems, dialectics and poetry thinking, methodology to comprehend laws by pansymmetries or by moving networks, the pansystems views of generalized order, quotientization and series‐parallel relations, control‐reachability, duality transformation, discoupling principle, communication theorems, general parental relations, etc.

Details

Kybernetes, vol. 29 no. 5/6
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 1 January 1989

Shashwati Guha and K.K. Aggarwal

The process by which the system failure allowance is allocated in some logical manner among its subsystems is termed Reliability Allocation. Many methods are available for such an…

Abstract

The process by which the system failure allowance is allocated in some logical manner among its subsystems is termed Reliability Allocation. Many methods are available for such an allocation for series system but no method exists in case the system is non‐series‐parallel. In this article, the optimum allocation of reliability among its subsystems for general non‐series‐parallel systems has been discussed by extending the Minimum Effort Method which in its present form is applicable for series systems only. A number of effort functions are listed with a view to finding one which is suitable for application in this method and the same has been used for further calculations.

Details

International Journal of Quality & Reliability Management, vol. 6 no. 1
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 15 July 2022

Mehrnaz Ahmadi and Mehdi Khashei

The purpose of this paper is to propose a new linear-nonlinear data preprocessing-based hybrid model to achieve a more accurate result at a lower cost for wind power forecasting…

Abstract

Purpose

The purpose of this paper is to propose a new linear-nonlinear data preprocessing-based hybrid model to achieve a more accurate result at a lower cost for wind power forecasting. For this purpose, a decomposed based series-parallel hybrid model (PKF-ARIMA-FMLP) is proposed which can model linear/nonlinear and certain/uncertain patterns in underlying data simultaneously.

Design/methodology/approach

To design the proposed model at first, underlying data are divided into two categories of linear and nonlinear patterns by the proposed Kalman filter (PKF) technique. Then, the linear patterns are modeled by the linear-fuzzy nonlinear series (LLFN) hybrid models to detect linearity/nonlinearity and certainty/uncertainty in underlying data simultaneously. This step is also repeated for nonlinear decomposed patterns. Therefore, the nonlinear patterns are modeled by the linear-fuzzy nonlinear series (NLFN) hybrid models. Finally, the weight of each component (e.g. KF, LLFN and NLFN) is calculated by the least square algorithm, and then the results are combined in a parallel structure. Then the linear and nonlinear patterns are modeled with the lowest cost and the highest accuracy.

Findings

The effectiveness and predictive capability of the proposed model are examined and compared with its components, based models, single models, series component combination based hybrid models, parallel component combination based hybrid models and decomposed-based single model. Numerical results show that the proposed linear-nonlinear data preprocessing-based hybrid models have been able to improve the performance of single, hybrid and single decomposed based prediction methods by approximately 66.29%, 52.10% and 38.13% for predicting wind power time series in the test data, respectively.

Originality/value

The combination of single linear and nonlinear models has expanded due to the theory of the existence of linear and nonlinear patterns simultaneously in real-world data. The main idea of the linear and nonlinear hybridization method is to combine the benefits of these models to identify the linear and nonlinear patterns in the data in series, parallel or series-parallel based models by reducing the limitations of the single model that leads to higher accuracy, more comprehensiveness and less risky predictions. Although the literature shows that the combination of linear and nonlinear models can improve the prediction results by detecting most of the linear and nonlinear patterns in underlying data, the investigation of linear and nonlinear patterns before entering linear and nonlinear models can improve the performance, which in no paper this separation of patterns into two classes of linear and nonlinear is considered. So by this new data preprocessing based method, the modeling error can be reduced and higher accuracy can be achieved at a lower cost.

Article
Publication date: 15 June 2010

Chao Lv, AiPing Li and LiYun Xu

The purpose of this paper is to research the impact of hybrid series‐parallel and parallel‐series system configurations on system performances based on system reliability and to…

564

Abstract

Purpose

The purpose of this paper is to research the impact of hybrid series‐parallel and parallel‐series system configurations on system performances based on system reliability and to develop a configuration model to meet the requirement of reconfigurable manufacturing system (RMS).

Design/methodology/approach

Based on the criterion of system reliability, a RMS configuration model is presented – the hybrid parallel‐series model with waiting system characteristics. The configuration model is evaluated from reliability, productivity, and cost by combining system engineering theory, Boolean algebra methodology with statistical analysis theory. The model reliability has been used to ameliorate by adopting the integrated algorithm based on Shrama and Misra optimization algorithm.

Findings

The need for application of this method and model – some constraints must be limited, the hybrid parallel‐series configuration is superior and the integrated algorithm is effective to RMS system configuration.

Research limitations/implications

Cost constraints, equipment weight constraints, and function independency of equipment are main limitations.

Practical implications

The model and method have been used to ameliorate the reconfigurable automobile parts product line in SH automobile motor company of Shanghai. The operation result illustrates the validity of this configuration model and algorithm.

Originality/value

The new RMSs configuration model has been proposed. The new algorithm is proposed to ameliorate and optimize a reconfigurable product line with the integrated algorithm based on Shrama and Misra algorithm. The actual running effect is significant.

Details

Kybernetes, vol. 39 no. 6
Type: Research Article
ISSN: 0368-492X

Keywords

1 – 10 of 299