A model for reliability analysis of multi-state manufacturing systems

2014 ◽  
Vol 31 (8) ◽  
pp. 938-949 ◽  
Author(s):  
Seyed Ahmad Niknam ◽  
Rapinder Sawhney
Keyword(s):  
Reliability Analysis ◽  
System Reliability ◽  
Design Methodology ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Production Systems ◽  
Case Scenario ◽  
Worst Case ◽  
Content Type ◽  
Proposed Model

Purpose – The purpose of this paper is to investigate the reliability analysis of a multi-state manufacturing system with different performance levels. In, fact, reliability assessment of manufacturing systems gives a reasonable demonstration of system performance. Design/methodology/approach – This research utilizes a multi-state system reliability analysis to develop a new metric for evaluating production systems. Findings – The proposed model provides a sensible measure to assess the system situation against the best-case scenario of a production line. Originality/value – The proposed model incorporates not only failures that stop production but also deals with partial failures where the system continues to operate at reduced performance rates. The analyses are represented in a best-case vs worst-case situation. Each of these cases provides insight for managers with respect to planning operation and maintenance activities.

Fuzzy assessment analysis and key improvements to a production system

2019 ◽  
Vol 32 (1) ◽  
pp. 38-55
Author(s):  
Yau-Ren Shiau ◽  
Hui-Min Chang
Keyword(s):  
Performance Appraisal ◽  
Design Methodology ◽  
Production Systems ◽  
Quality Factors ◽  
Quality Performance ◽  
Content Type ◽  
Proposed Model ◽  
Fuzzy Assessment ◽  
Tools And Techniques ◽  
And Control

Purpose The framework of Six Sigma Define-Measure-Analyze-Improve-Control was applied in this study, and various tools and techniques were used at different stages to implement lean measures to ensure quality. The purpose of this paper is to develop a decision-making framework that assesses key quality performance to ensure that practitioners improve quality and control by modeling and optimizing production processes. Design/methodology/approach A model of a quality performance index system was established. The weights of factors and sub-factors, which were estimated using an FAHP, were used as a reference for the decision maker under fuzzy uncertainly to make a decision, and thus, results present the bottlenecks in processes. Furthermore, any other factors that may affect the key process bottlenecks must be considered. The critical to quality characteristics were determined, and factor levels were set. The interaction between the factors was analyzed, their significance was studied using the Design of experiments and the parameters were predicted. Finally, quality improvement decisions were made through failure mode and effects analysis. Findings The implementation results of this research prove that the proposed model could successfully determine the key processes and focus on the improvement of critical quality factors under limited resources. Originality/value This study establishes a set of performance appraisal methods for production systems, which can be used for improving productivity and quality.

A methodology for the reconfiguration process in manufacturing systems

2014 ◽  
Vol 25 (6) ◽  
pp. 891-915 ◽  
Author(s):  
Ibrahim H. Garbie
Keyword(s):  
System Design ◽  
Manufacturing Systems ◽  
Material Handling ◽  
Manufacturing System ◽  
Production Systems ◽  
Systems Design ◽  
Production Volume ◽  
Plant Layout ◽  
Content Type ◽  
Handling System

Purpose – The purpose of this paper is to propose a “Reconfiguration Methodology” in manufacturing systems that they can become more economically sustainable and can operate efficiency and effectively. This methodology will allow customized flexibility and capacity not only in producing a variety of products (parts) and with changing market demands, but also in changing and reengineering the system itself. Design/methodology/approach – Reconfigurable manufacturing system (RMS) is a philosophy or strategy which was introduced during the last decade to achieve agility in manufacturing systems. Until now, the RMS philosophy was based changing activities such routing, planning, programming of machines, controlling, scheduling, and physical layout or materials handling system. But the RMS concept can be based on the needed reconfiguration level (NRL), operational status of production systems, and new circumstances (NC). The NRL measure is based on the agility level of the manufacturing systems which is based on technology, people, management, and manufacturing strategies. The components of the manufacturing system design (MSD) consist of production system design, plant layout system, and material handling system. Operational status of production systems includes machine capability (flexibility) and capacity (reliability), production volume or demand, and material handling equipment in addition to the plant layout. The NC are also consisting of new product, developing the existing ones, and changing in demand. Findings – Reconfiguration manufacturing systems from one period to another period is highly desired and is considered as a novel manufacturing philosophy and/or strategy toward creating new sustainable manufacturing systems. A new reconfiguration methodology for the manufacturing systems will be analyzed and proposed. Two Case studies will be introduced. Originality/value – The suggestion of a new methodology of reconfiguration including the NRL (configurability index) and the operational status of manufacturing systems with respect to any circumstance is highly considered. The reconfiguration methodology also provides a framework for sustainability in the manufacturing area which mainly focussed on manufacturing systems design.

Risk-Based Robust Bidding Strategies for EVs’ Aggregators in Day-ahead Markets with Uncertainty

2020 ◽  
Author(s):  
Ahmed Abdelmoaty ◽  
Wessam Mesbah ◽  
Mohammad A. M. Abdel-Aal ◽  
Ali T. Alawami
Keyword(s):  
Robust Optimization ◽  
Electricity Market ◽  
Real Life ◽  
Optimization Approach ◽  
Case Scenario ◽  
Worst Case ◽  
Bidding Strategies ◽  
Wind Generators ◽  
Proposed Model ◽  
Optimal Bidding

In the recent electricity market framework, the profit of the generation companies depends on the decision of the operator on the schedule of its units, the energy price, and the optimal bidding strategies. Due to the expanded integration of uncertain renewable generators which is highly intermittent such as wind plants, the coordination with other facilities to mitigate the risks of imbalances is mandatory. Accordingly, coordination of wind generators with the evolutionary Electric Vehicles (EVs) is expected to boost the performance of the grid. In this paper, we propose a robust optimization approach for the coordination between the wind-thermal generators and the EVs in a virtual<br>power plant (VPP) environment. The objective of maximizing the profit of the VPP Operator (VPPO) is studied. The optimal bidding strategy of the VPPO in the day-ahead market under uncertainties of wind power, energy<br>prices, imbalance prices, and demand is obtained for the worst case scenario. A case study is conducted to assess the e?effectiveness of the proposed model in terms of the VPPO's profit. A comparison between the proposed model and the scenario-based optimization was introduced. Our results confirmed that, although the conservative behavior of the worst-case robust optimization model, it helps the decision maker from the fluctuations of the uncertain parameters involved in the production and bidding processes. In addition, robust optimization is a more tractable problem and does not suffer from<br>the high computation burden associated with scenario-based stochastic programming. This makes it more practical for real-life scenarios.<br>

Road to default: Tracoma holding Berhad Bai Bithaman Ajil Debt securities (BaIDS)

2015 ◽  
Vol 5 (5) ◽  
pp. 1-6
Author(s):  
A.M. Hafizi ◽  
Shahida Shahimi ◽  
Mohd Hafizuddin Syah Bangaan Abdullah ◽  
M. Badrul Hakimi Daud
Keyword(s):  
Learning Outcomes ◽  
Capital Market ◽  
Credit Rating ◽  
Subject Area ◽  
Capital Requirements ◽  
Fund Raising ◽  
Case Scenario ◽  
Worst Case ◽  
Content Type ◽  
Analytical Skills

Subject area Islamic Finance and Investment Study level/applicability Level of program/audience: Advanced undergraduate and postgraduate. Courses Intermediate and Advanced Finance, Economics, Islamic Economics & Finance, Islamic Banking & Finance, Islamic Capital Market and other relevant courses. Specifictopics/syllabus Capital markets instruments, conventional or Islamic. Case overview This case focuses on Tracoma Holding Berhad Bai Bithaman Ajil Debt Securities (BaIDS) amounting to RM 100 million which was issued by Tracoma Holding Berhad in 2005. It was the first issuance of a sukuk (Islamic debt securities or bond) by the company. The proceeds were used to finance its growth and to repay existing bank borrowings and capital requirements. This case is interesting, as it allows students to study the bai bithaman ajil sukuk structure and issuance process in the Malaysian capital market. It also provides basic financial transaction and credit rating of sukuk which requires analytical skills. Being a debt-based facility, the sukuk was subjected to credit rating evaluation by the MARC, the rating agency appointed by the company. Further downgrading of the sukuk meant it would lead to the worst-case scenario. Some actions needed to be taken to solve this issue; therefore, the CFO suggested an urgent meeting with the sukuk holders. Expected learning outcomes The students should be able to: understand the issuance process and the principle of BBA (bai bithamin ajil) in sukuk structure; understand reason(s) methods of fund raising by firm and the allocations of fund; understand the sukuk default issue; analyze the reasons for sukuk default; understand the importance of debt securities credit ratings; and identify investors' protection in the case of sukuk default. Supplementary materials Teaching notes are available for educators only. Please contact your library to gain login details or email [email protected] to request teaching notes.

Modeling multi-state system reliability analysis in a power station under fatal and nonfatal shocks: a simulation approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Reza Pourhassan ◽  
Sadigh Raissi ◽  
Arash Apornak
Keyword(s):  
Reliability Analysis ◽  
System Reliability ◽  
System Performance ◽  
Failure Process ◽  
State System ◽  
Failure Behavior ◽  
Simulation Approach ◽  
Critical System ◽  
Content Type ◽  
System Reliability Analysis

PurposeIn some environments, the failure rate of a system depends not only on time but also on the system condition, such as vibrational level, efficiency and the number of random shocks, each of which causes failure. In this situation, systems can keep working, though they fail gradually. So, the purpose of this paper is modeling multi-state system reliability analysis in capacitor bank under fatal and nonfatal shocks by a simulation approach.Design/methodology/approachIn some situations, there may be several levels of failure where the system performance diminishes gradually. However, if the level of failure is beyond a certain threshold, the system may stop working. Transition from one faulty stage to the next can lead the system to more rapid degradation. Thus, in failure analysis, the authors need to consider the transition rate from these stages in order to model the failure process.FindingsThis study aims to perform multi-state system reliability analysis in energy storage facilities of SAIPA Corporation. This is performed to extract a predictive model for failure behavior as well as to analyze the effect of shocks on deterioration. The results indicate that the reliability of the system improved by 6%.Originality/valueThe results of this study can provide more confidence for critical system designers who are engaged on the proper system performance beyond economic design.

Sprawl of the COVID-19 in changing scenario: a methodology based on social interaction

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gaurav Kumar ◽  
Akshay Kumar ◽  
Farhan Mohammad Khan ◽  
Rajiv Gupta
Keyword(s):  
Social Interaction ◽  
Design Methodology ◽  
Mitigation Strategy ◽  
Recent Past ◽  
Scenario Development ◽  
Worst Case ◽  
Content Type ◽  
Management Scheme ◽  
Business As Usual ◽  
Inter State

PurposeThere are several methods developed in the recent past to predict the spread of COVID-19 in different countries. However, due to changing scenarios in terms of interaction among people, none could predict the case close to the actual figures. An attempt to simulate people's interaction due to economic reopening concerning the confirmed cases at various places as per changing situation has been made. The scenario development method's base lies in the hypothesis that if there were no inter-state transportation during India's lockdown after May 24th, the number of infection cases would have started lowering down in a normalized progression.Design/methodology/approachThis study has developed three scenarios from the worst to the business-as-usual to the best in order to project the COVID-19 infections in India concerning infections observed from January 30th till May 24th, 2020, since the domestic flights became operational from May 25th, 2020, in India.FindingsBased on the observed cases till May 24th, the rise of cases is projected further in a random progression and superimposed to the normal progression. The results obtained in the three scenarios present that worst case needs complete lockdown, business-as-usual case needs regulatory lockdown and best case assures complete lockdown release by the second week of September 2020. This study suggests the preparedness and mitigation strategy for a threefold lockdown management scheme in all-inclusive.Originality/valueThe work has been done on a hypothesis which is solely original.

Production models of multiple products using a single machine under quality screening and reworking policies

2019 ◽  
Vol 14 (1) ◽  
pp. 232-259 ◽  
Author(s):  
Ata Allah Taleizadeh ◽  
Mahshid Yadegari ◽  
Shib Sankar Sana
Keyword(s):  
Single Machine ◽  
Manufacturing Systems ◽  
Production Systems ◽  
Production Costs ◽  
High Tech ◽  
Screening Process ◽  
Automatic Production ◽  
Content Type ◽  
Economic Production ◽  
Imperfect Items

Purpose The purpose of this study is to formulate two multi-product single-machine economic production quantity (EPQ) models by considering imperfect products. Two policies are assumed to deal with imperfect products: selling them at discount and applying a reworking process. Design/methodology/approach A screening process is used to identify imperfect items during and after production. Selling the imperfect items at a discount is examined in the first model and the reworking policy in the second model. In both models, demand during the production process is satisfied only by perfect items. Data collected from a case company are used to illustrate the performance of the two models. Moreover, a sensitivity analysis is carried out by varying the most important parameters of the models. Findings The case study in this research is used to demonstrate the applicability of the proposed models, i.e. the EPQ model with salvaging and reworking imperfect items. The models are applied to a high-tech un-plasticized polyvinyl chloride (UPVC) doors and windows manufacturer that produces different types of doors and windows. ROGAWIN Co. is a privately owned company that started in 2001 with fully automatic production lines. Finally, the results of applying the different ways of handling the imperfect items are discussed, along with managerial insights. Originality/value In real-world production systems, manufacturing imperfect products is unavoidable. That is why, it is important to make a proper decision about imperfect products to reduce overall production costs. Recently, applying a reworking strategy has gained the most interest when it comes to handling this problem. The principal idea of this research is to maximize the total profit of manufacturing systems by optimizing the period length under some capacity constraints. The proposed models were applied to a company of manufacturing UPVC doors and windows.

Importance measures for degrading components based on cooperative game theory

2019 ◽  
Vol 37 (2) ◽  
pp. 189-206
Author(s):  
Yingsai Cao ◽  
Sifeng Liu ◽  
Zhigeng Fang
Keyword(s):  
Cooperative Game ◽  
Shapley Value ◽  
System Reliability ◽  
Design Methodology ◽  
System Structure ◽  
Importance Measure ◽  
Engineering Systems ◽  
Content Type ◽  
Timely Feedback ◽  
Degradation Models

Purpose The purpose of this paper is to propose new importance measures for degrading components based on Shapley value, which can provide answers about how important players are to the whole cooperative game and what payoff each player can reasonably expect. Design/methodology/approach The proposed importance measure characterizes how a specific degrading component contributes to the degradation of system reliability by using Shapley value. Degradation models are also introduced to assess the reliability of degrading components. The reliability of system consisting independent degrading components is obtained by using structure functions, while reliability of system comprising correlated degrading components is evaluated with a multivariate distribution. Findings The ranking of degrading components according to the newly developed importance measure depends on the degradation parameters of components, system structure and parameters characterizing the association of components. Originality/value Considering the fact that reliability degradation of engineering systems and equipment are often attributed to the degradation of a particular or set of components that are characterized by degrading features. This paper proposes new importance measures for degrading components based on Shapley value to reflect the responsibility of each degrading component for the deterioration of system reliability. The results are also able to give timely feedback of the expected contribution of each degrading component to system reliability degradation.

scholarly journals The flexibility of industrial additive manufacturing systems

2018 ◽  
Vol 38 (12) ◽  
pp. 2313-2343 ◽  
Author(s):  
Daniel R. Eyers ◽  
Andrew T. Potter ◽  
Jonathan Gosling ◽  
Mohamed M. Naim
Keyword(s):  
Additive Manufacturing ◽  
Operations Management ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Detailed Examination ◽  
Multiple Sources ◽  
Content Type ◽  
Commercial Practice ◽  
Systems Perspective ◽  
Manufacturing Operations

Purpose Flexibility is a fundamental performance objective for manufacturing operations, allowing them to respond to changing requirements in uncertain and competitive global markets. Additive manufacturing machines are often described as “flexible,” but there is no detailed understanding of such flexibility in an operations management context. The purpose of this paper is to examine flexibility from a manufacturing systems perspective, demonstrating the different competencies that can be achieved and the factors that can inhibit these in commercial practice. Design/methodology/approach This study extends existing flexibility theory in the context of an industrial additive manufacturing system through an investigation of 12 case studies, covering a range of sectors, product volumes, and technologies. Drawing upon multiple sources, this research takes a manufacturing systems perspective that recognizes the multitude of different resources that, together with individual industrial additive manufacturing machines, contribute to the satisfaction of demand. Findings The results show that the manufacturing system can achieve seven distinct internal flexibility competencies. This ability was shown to enable six out of seven external flexibility capabilities identified in the literature. Through a categorical assessment the extent to which each competency can be achieved is identified, supported by a detailed explanation of the enablers and inhibitors of flexibility for industrial additive manufacturing systems. Originality/value Additive manufacturing is widely expected to make an important contribution to future manufacturing, yet relevant management research is scant and the flexibility term is often ambiguously used. This research contributes the first detailed examination of flexibility for industrial additive manufacturing systems.

Investigating the effects of operators on warranty cost under sales delay conditions

2018 ◽  
Vol 24 (2) ◽  
pp. 244-259
Author(s):  
Sepideh Eskandari Dorabati ◽  
Ali Zeinal Hamadani ◽  
Hamed Fazlollahtabar
Keyword(s):  
Data Analysis ◽  
Design Methodology ◽  
Claims Data ◽  
Time Interval ◽  
Content Type ◽  
Proposed Model ◽  
Warranty Cost ◽  
Warranty Costs ◽  
Warranty Claims ◽  
Claims Data Analysis

Purpose Due to the fact that the non-standard products, being used by customers, may cause failures in products with sales delays, which naturally affect the warranty policy. Thus, it seems to be necessary to study these two concepts simultaneously. The paper aims to discuss these issues. Design/methodology/approach In this paper, a model is developed for estimating the expected warranty costs under sales delay conditions when two operator costs (failing but not reported and non-failing but reported) are included. Findings The proposed model is validated using a numerical example for a two types of intermittent and fatal failures occur under a non-renewing warranty policy. Originality/value Sales delay is the time interval between the date of production and the date of sale. Most reported literature on warranty claims data analysis related to sales delay have mainly focussed on estimating the probability distribution of the sales delay.

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