A Simulation and Modeling Based Reliability Requirements Assessment Methodology

2014 ◽  
Author(s):  
Tomonori Honda ◽  
Eric Saund ◽  
Ion Matei ◽  
Bill Janssen ◽  
Bhaskar Saha ◽  
...  
Keyword(s):  
System Reliability ◽  
Failure Modes ◽  
Vehicle Design ◽  
Assessment Methodology ◽  
Exploration Tool ◽  
Design Case Study ◽  
The Cost ◽  
Design Cost ◽  
The Impact

To minimize the design cost of a complex system and maximize performance, a design team ideally must be able to quantify reliability and mitigate risk at the earliest phases of the design process, where 80% of the cost is committed. This paper demonstrates the capabilities of a new System Reliability Exploration Tool based on the improved simulation capabilities of a system called Fault-Augmented Modelica Extension (FAME). This novel tool combines concepts from FMEA, traditional Reliability Analysis, and Quality Engineering to identify, gain insight, and quantify the impact of component failure modes through time evolution of a system’s lifecycle. We illustrate how to use the FAME System Reliability Exploration Tool through a vehicle design case study.

scholarly journals The Potential of a Cost-Per-Use Analysis to Assess the Value of Library Open-Access Funds

2018 ◽  
Vol 13 (4) ◽  
pp. 99-101
Author(s):  
Jessica Koos
Keyword(s):  
Open Access ◽  
Biomed Central ◽  
Journal Articles ◽  
Level Data ◽  
Article Usage ◽  
Article Processing Charges ◽  
The Cost ◽  
Design Cost ◽  
The Impact

A Review of: Hampson, C., & Stregger, E. (2017). Measuring cost per use of library-funded open access article processing charges: Examination and implications of one method. Journal of Librarianship & Scholarly Communication, 5(1), eP2182. https://doi.org/10.7710/2162-3309.2182 Abstract Objective – To determine the feasibility and potential effects of a cost-per-use analysis of library funds dedicated to open access. Design – Cost-per-use analysis, case study. Setting – PLOS and BioMed Central. Subjects – 591 articles published in PLOS ONE, 165 articles published in PLOS Biology, and 17 articles published in BioMed Central. Methods – Three specific examples are provided of how academic libraries can employ a cost-per-use analysis in order to determine the impact of library-based open access (OA) funds. This method is modeled after the traditional cost-per-use method of analyzing a library collection, and facilitates comparison to other non-OA items. The first example consisted of using a formula dividing the total library-funded article processing charges (APCs) by the total global use of the specific PLOS journal articles that were funded. The second and third examples demonstrated what a library-funded OA membership to BioMed Central would cost alone, and then with APCs that cost could be divided by the total usage of the funded articles to determine cost-per-use. Main Results – The authors found both of the examples described in the article to be potential ways of determining cost-per-use of OA articles, with some limitations. For instance, counting article usage through the publisher’s website may not capture the true usage of an article, as it does not take altmetrics into consideration. In addition, article-level data is not always readily available. In addition, the cost-per-use of OA articles was found to be very low, ranging from $0.01 to $1.51 after the first three years of publication based on the cost of library-funded APCs. The second and third methods revealed a cost-per-use of $0.10 using membership-only payments, while using the cost of membership plus APCs resulted in a cost-per-use of $0.41. Conclusion – Libraries may wish to consider using these methods for demonstrating the value of OA funds in terms of return on investment, as these techniques allow for direct comparison to the usage of traditional journals. However, several barriers need to be overcome in how article-level usage is obtained in order for these methods to be more accurate and efficient. In addition, while the authors report that "The specific examples in this study suggest that OA APCs may compare favorably to traditional publishing when considering value for money based on cost per use," they also caution that the study was not designed to answer the question if the ROI is greater for OA publications than for traditional articles, stating that "...the data in this study should not be interpreted as a verification of such an argument, as this study was not designed to answer that question, nor can it do so given the limitations on the data. This paper was designed to present and illustrate a method. Further study would be necessary to verify or refute this possibility" (p. 15).

scholarly journals Reliability of Supply and the Impact of Weather Exposure and Protection System Failures

2020 ◽  
Vol 11 (1) ◽  
pp. 182
Author(s):  
Erlend Sandø Kiel ◽  
Gerd Hovin Kjølle
Keyword(s):  
System Reliability ◽  
Failure Modes ◽  
Extreme Weather ◽  
Test System ◽  
Protection System ◽  
Electrical Transmission ◽  
System Failures ◽  
Reliability Indices ◽  
The Impact

Extreme weather is known to cause failure bunching in electrical transmission systems. However, protection systems can also contribute to the worsening of the system state through various failure modes—spontaneous, missing or unwanted operation. The latter two types of failures only occur when an initial failure has happened, and thus are more likely to happen when the probability of failure of transmission lines is high, such as in an extreme weather scenario. This causes an exacerbation of failure bunching effects, increasing the risk of blackouts, or High Impact Low Probability (HILP) events. This paper describes a method to model transmission line failure rates, considering both protection system reliability and extreme weather exposure. A case study is presented using the IEEE 24 bus Reliability Test System (RTS) test system. The case study, using both an approximate method as well as a time-series approach to calculate reliability indices, demonstrates both a compact generalization of including protection system failures in reliability analysis, as well as the interaction between weather exposure and protection system failures and its impact on power system reliability indices. The results show that the inclusion of protection system failures can have a large impact on the estimated occurrence of higher order contingencies for adjacent lines, especially for lines with correlated weather exposure.

scholarly journals Evaluation of the Impact of Timber Truck Configuration and Tare Weight on Payload Efficiency: An Australian Case Study

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 855
Author(s):  
Mark W. Brown
Keyword(s):  
Load Management ◽  
Vehicle Design ◽  
Forest Industry ◽  
Post Operation ◽  
Gross Vehicle Weight ◽  
Australian Case ◽  
Trends Over Time ◽  
The Impact

The forest industry tends to plan, and model transportation costs based on the potential payload benefits of increased legal gross vehicle weight (GVW) by deploying different configurations, while payload benefits of a configuration can be significantly influenced by the vehicle design tare weight. Through this research the relative benefit of increased legal GVW of different configurations is compared across Australia over a 13-year period from 2006 to 2019, by examining data collected post operation across multiple operations. This approach is intended to offer realistic insight to real operations not influenced by observation and thus reflect long-term operating behaviour. The inclusion of the three most common configuration classes in Australian forestry over a 13-year period has also allowed the exploration of load management between configurations and potential trends over time. When considering the legal GVW and the tare weight impacts across the fleets, the semi-trailer has an 8 t payload disadvantage compared to B-Doubles and 19.6 t disadvantage compared to road trains.

Optimal Reliability and Cost of Non-Repairable Systems Subject to Two Failure Modes Considering Correlated Failures

2018 ◽  
Vol 25 (05) ◽  
pp. 1850024
Author(s):  
Anusha Krishna Murthy ◽  
Saikath Bhattacharya ◽  
Lance Fiondella
Keyword(s):  
Failure Mode ◽  
System Reliability ◽  
Failure Modes ◽  
Optimal Number ◽  
Optimal Designs ◽  
Repairable Systems ◽  
Independent Manner ◽  
Reliability Models ◽  
Correlated Failures ◽  
The Impact

Most reliability models assume that components and systems experience one failure mode. Several systems such as hardware, however, are prone to more than one mode of failure. Past two-failure mode research derives equations to maximize reliability or minimize cost by identifying the optimal number of components. However, many if not all of these equations are derived from models that make the simplifying assumption that components fail in a statistically independent manner. In this paper, models to assess the impact of correlation on two-failure mode system reliability and cost are developed and corresponding expressions for reliability and cost optimal designs derived. Our illustrations demonstrate that, despite correlation, the approach identifies reliability and cost optimal designs.

Value Implications of Green Design: Case Study of a Videocassette

1996 ◽  
Author(s):  
Anne-Claire Kopp ◽  
Robert H. Sturges
Keyword(s):  
Green Design ◽  
Green Products ◽  
Resource Analysis ◽  
Joint Project ◽  
Physical Attributes ◽  
Design Case ◽  
Design Case Study ◽  
The Cost ◽  
Time And Energy

Abstract Recent concern for the environment has caused growing attention to recycling, both using recycled materials to make products and recycling products after use. Although environmentalists may be eager to buy recycled/recyclable products, other consumers may not be so easily convinced. It may also be difficult to convince manufacturers that it is beneficial to develop green products. This paper supports a joint project between engineering and marketing disciplines to determine the cost and value of an environmentally designed product. Specifically, this paper evaluates the resources spent to manufacture a green videocassette in comparison with a standard videocassette by performing a resource analysis. This analysis estimates the cost, time and energy necessary to produce both videocassettes. This paper also compares the value of the videocassettes in terms of performance and physical attributes.

Probability of Uncontrolled External Leakage During the Production Phase of a Subsea Well

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
André L. R. Alves ◽  
T. A. Netto
Keyword(s):  
Failure Modes ◽  
Base Case ◽  
Component Reliability ◽  
Production Phase ◽  
Distribution Parameters ◽  
Common Cause Failures ◽  
Integrity Management ◽  
Closed Position ◽  
The Impact

Abstract This work presents a methodology for evaluating the uncontrolled external leakage probability of a subsea well during the production phase. Based on a barrier diagram, an algorithm for possible leak path identification is proposed, considering different operation modes: gas lift operation, free-flowing, or well closed at the subsea Christmas tree. Considering the equivalency between these paths and the minimum cut sets from a fault tree modeling, the uncontrolled external leakage probability is calculated using the upper bound approximation. The effect of common cause failures is considered for the failure mode fail-to-close-valve. The instantaneous availability function of each component is considered. Non-repairable, repairable, and periodically tested items are used. Probability distribution parameters are estimated in order to make a case study. The failure rate functions determined are used as input for the proposed model, regarding the following failure modes: fail-to-close, external-leakage, and internal-leakage at the closed position. Finally, failure probability results and sensitivity analysis are demonstrated for a base case study. Parameters like time between tests, inspections, and component reliability are varied in order to identify the impact on the uncontrolled external leakage probability. The main objective of the proposed methodology is to support decision-making on the well integrity management system during the production phase of a subsea well. To this end, actual and reliable input data should be considered.

scholarly journals Estimating the Impact of Medical Innovation: A Case Study of HIV Antiretroviral Treatments

2008 ◽  
Vol 11 (2) ◽  
Author(s):  
Mark G Duggan ◽  
William N Evans
Keyword(s):  
Health Care ◽  
Good Alternative ◽  
Care Utilization ◽  
Short Term ◽  
Fda Approval ◽  
New Treatments ◽  
The Cost ◽  
The Impact ◽  
Average Health

As health care consumes a growing share of GDP, the demand for better evidence regarding the effects of health care treatments and how these vary across individuals is increasing. Estimating this with observational data is difficult given the endogeneity of treatment decisions. But because the random assignment clinical trials (RACTs) used in the FDA approval process only estimate average health effects and do not consider spending, there is no good alternative. In this study we use administrative data from California's Medicaid program to estimate the impact of HIV antiretroviral treatments (ARVs). We use data on health care utilization to proxy for health status and exploit the rapid takeup of ARVs following their FDA approval. Our estimate of a 68 percent average mortality rate reduction is in line with the results from RACTs. We also find that the ARVs lowered short-term health care spending by reducing expenditures on other categories of medical care. Combining these two effects we estimate the cost per life year saved at $19,000. Our results suggest an alternative method for estimating the real-world effects of new treatments that is especially well-suited to those treatments that diffuse rapidly following their approval.

scholarly journals THE IMPACT OF PRODUCT LIFE CYCLE TECHNIQUE IN REDUCING COSTS AND ACHIEVING SUSTAINABLE DEVELOPMENT GOALS, A CASE STUDY IN THE RUSTAN STEEL STRUCTURE PRODUCTION COMPANY IN ERBIL

2021 ◽  
Vol 03 (07) ◽  
pp. 314-328
Author(s):  
Ghazi Abdulazeez SULAIMAN BAG ◽  
Rafiq Faraj MAHMOOD
Keyword(s):  
Corporate Governance ◽  
Life Cycle ◽  
Life Cycle Cost ◽  
Product Life Cycle ◽  
Steel Structures ◽  
Product Life ◽  
Technical Requirements ◽  
The Cost ◽  
The Impact

This research was - case study in Rstin company for the steel structures in Erbil- addressed the cost technique of product life cycle, as discussed the kinds, relevance and the stages of the life cycle of the product, also it referred to the corporate governance of discussing its inception the concept and importance of the principles, objectives, and mechanisms was addressed to the technical aspects of the overlap between the cost of the product life cycle corporate governance and show the appropriate techniques used in each stage of the life cycle of the product and how it achieved by a reduction of costs. The result of this study indicates that the integration between the product life cycle cost and corporate governance works on reduce costs through the various stages of product life cycle. It also concluded that this integration increases the company ability to compete in market which leads to rise in its market share and eventually lead to maximize the profit which has been achieved through the optimal use of a company available resources. It also found that the techniques of life cycle cost of the product cannot be applied without support of the company directors, throughout the technical requirements of the application. Corporate governance ensures directors of the company to utilize firm resources which makes the company to achieve several stakeholders' objectives.

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