scholarly journals Condition-Based Maintenance of HVAC on a High-Speed Train for Fault Detection

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1418
Author(s):  
Lorenzo Ciani ◽  
Giulia Guidi ◽  
Gabriele Patrizi ◽  
Diego Galar
Keyword(s):  
Decision Making ◽  
High Speed ◽  
Failure Modes ◽  
Air Conditioning System ◽  
Suggested Approach ◽  
Reliability Centered Maintenance ◽  
High Speed Trains ◽  
Optimal Maintenance ◽  
The Cost ◽  
Maintenance Plan

Reliability-centered maintenance (RCM) is a well-established method for preventive maintenance planning. This paper focuses on the optimization of a maintenance plan for an HVAC (heating, ventilation and air conditioning) system located on high-speed trains. The first steps of the RCM procedure help in identifying the most critical items of the system in terms of safety and availability by means of a failure modes and effects analysis. Then, RMC proposes the optimal maintenance tasks for each item making up the system. However, the decision-making diagram that leads to the maintenance choice is extremely generic, with a consequent high subjectivity in the task selection. This paper proposes a new fuzzy-based decision-making diagram to minimize the subjectivity of the task choice and preserve the cost-efficiency of the procedure. It uses a case from the railway industry to illustrate the suggested approach, but the procedure could be easily applied to different industrial and technological fields. The results of the proposed fuzzy approach highlight the importance of an accurate diagnostics (with an overall 86% of the task as diagnostic-based maintenance) and condition monitoring strategy (covering 54% of the tasks) to optimize the maintenance plan and to minimize the system availability. The findings show that the framework strongly mitigates the issues related to the classical RCM procedure, notably the high subjectivity of experts. It lays the groundwork for a general fuzzy-based reliability-centered maintenance method.

scholarly journals Multicriteria FMECA Based Decision-Making for Aluminium Wire Process Rolling Mill through COPRAS-G

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Nilesh Pancholi ◽  
M. G. Bhatt
Keyword(s):  
Decision Making ◽  
Failure Mode ◽  
Rolling Mill ◽  
Failure Modes ◽  
Current Control ◽  
Aluminium Wire ◽  
Grey Number ◽  
Criticality Index ◽  
Criticality Analysis ◽  
Maintenance Plan

This paper presents a multifactor decision-making approach based on “grey-complex proportional assessment (COPRAS-G) method” in a view to overcome the limitations of Failure Mode Effect and Criticality Analysis (FMECA). In this model, the scores against each failure mode are expressed in grey number instead of crisp values to evaluate the criticalities of the failure modes without uncertainty. The suggested study is carried out to identify the weights of major failure causes for bearings, gears, and shafts of aluminium wire rolling mill plant. The primary findings of the paper are that sudden impact on the rolls seems to be most critical failure cause and loss of power seems to be least critical failure cause. It is suggested to modify the current control practices with proper maintenance strategy based on achieved maintainability criticality index (MCI) for different failure causes. The outcome of study will be helpful in deriving optimized maintenance plan to maximize the performance of process industry.

scholarly journals Analyzing the Long-Term Service Life of MEP Using the Probabilistic Approach in Residential Buildings

2018 ◽  
Vol 10 (10) ◽  
pp. 3803 ◽  
Author(s):  
Sanghyo Lee ◽  
Yonghan Ahn
Keyword(s):  
Decision Making ◽  
Service Life ◽  
Residential Buildings ◽  
Probabilistic Approach ◽  
Life Time ◽  
Probabilistic Methods ◽  
The Cost ◽  
Maintenance Plan ◽  
Term Maintenance

Establishing an effective long-term maintenance plan is essential to ensure the sustainability of a building. Among the various components of a building, the mechanical, electrical, and plumbing (MEP) components are complexly affected by various parameters, such as quality and user pattern, with respect to the service life. Besides, these components are replaced at different points in time, which becomes one of the main risks when establishing a maintenance plan for the building. Therefore, it is very important to consider the uncertainty in calculating the service lives of MEP components in a systematic and reasonable way. This study aims to systemize the MEP components of residential buildings and analyze their service life patterns using a probabilistic approach for long-term maintenance planning. The analysis was performed on 54,318 maintenance cases from 1998 to 2017 at 65 twenty-five-year-old rental apartment buildings in South Korea. Before performing the analysis, a service life matrix was established by classifying the MEP components into 12 types and setting the service life time at 6–25 years. Then, the service life distribution was derived for each MEP component. The probabilistic approach can provide information for rational maintenance decision-making regarding each MEP component as well as basic service life settings. Since the performance of the MEP components deteriorates due to various reasons, de facto uncertainty exists in the service life of each component; thus, the probabilistic approach can serve as an important decision-making method. If probabilistic methods are developed by acquiring the cost data in addition to the frequency of maintenance activity used in this study, a more effective long-term maintenance plan can be established.

Application status and developing foreground of CRTS Ⅲ ballastless track

2018 ◽  
Author(s):  
Bai Jing-Yuan ◽  
Bin Yan
Keyword(s):  
High Speed ◽  
Driving Forces ◽  
Curved Space ◽  
Unit Structure ◽  
Ballastless Track ◽  
National Economic ◽  
High Speed Trains ◽  
The Cost ◽  
Ca Mortar ◽  
Track Slab

<p>The technology of high-speed railway is one of the central driving forces in national economic growth. To increase the speed of high-speed trains and ensure their safety, the research and development of brand-new ballastless track techniques are of vital significance. This article simply talked about China's domestically designed CRTS III ballastless track. This technique is famous for some technical characteristics: it replaced CA mortar with self-compacting concrete as adjustment layer, which not only simplified the structure but also reduced the cost; 2-D scalable steel mould was adopted to materialize the track slab with high precision shoulder post-tensioned prestressed spatial curved space, which simplified the construction craft a lot; it adopted flexible longitudinal coupled structure of the subgrade as bridge-tunnel unit structure, which weakened the influence of temperature stress; unit-separated structure and flexible-separated structure were widely used, which made the maintainability of all unit structure. This article was based on the analysis of these technical characteristics and discussed the application status and developing foreground of this technique in some way.</p>

scholarly journals A Reliability-Centered Maintenance Study for an Individual Section Forming Machine

2018 ◽  
Author(s):  
Samuel Okwuobi ◽  
Felix Ishola ◽  
Oluseyi Ajayi
Keyword(s):  
Failure Modes ◽  
Special Focus ◽  
Effect Analysis ◽  
Automated Production ◽  
Individual Section ◽  
Reliability Centered Maintenance ◽  
Maintenance Program ◽  
Optimal Maintenance ◽  
Critical Components ◽  
Functional Components

This study investigated the breakdown trend in an automated production with an aim to recommend the application of Reliability-centered maintenance (RCM) for an improved productivity via a new preventive maintenance (PM) program. Individual Section-forming machine (ISM): a glass blowing machine for making glass bottles was used as the case study of an automated production system. The machine parts and the working mechanisms were analysed with a special focus on methods of processes and procedures that will enable the ISM maintenance department run more effective and achieve its essential goal of ensuring effective machine operation and reducing machine downtime. In this work, information is provided on the steps and procedures to identify critical components of the ISM using Failure Modes and Effect Analysis (FMEA) as a tool to develop an optimal maintenance program based on the reliability data of the equipment&rsquo;s functional components. A relationship was established between the failure rate of the machine components&nbsp;and the&nbsp;maintenance&nbsp;costs such that using the recommended PM program, an evidence of improvement in the machine&rsquo;s availability, safety and cost-effectiveness will result into an increase in the company&rsquo;s profit margin.

Bayesian Networks on Risk Analysis of a Regasification System on an Offshore Unit

2011 ◽  
Author(s):  
Adriana Miralles Schleder ◽  
Marcelo Ramos Martins ◽  
Gilberto Francisco Martha Souza
Keyword(s):  
Risk Analysis ◽  
Bayesian Networks ◽  
Failure Modes ◽  
Terrorist Attack ◽  
Fault Trees ◽  
Reliability Centered Maintenance ◽  
Considerable Impact ◽  
Cut Set ◽  
Maintenance Plan

Nowadays, LNG Import Terminals (where the storage and regasification process is conducted) are mostly onshore; the construction of these terminals is costly and many adaptations are necessary to abide by environmental and safety laws. Moreover, an accident in one of these plants might produce considerable impact in neighboring areas and population; this risk may be even worse due to the possibility of a terrorist attack. Under this perspective, a discussion is conducted about a vessel known as FSRU (Floating Storage and Regasification Unit), which is a storage and regasification offshore unit, that can work miles away from de coast and, owing to this, can be viewed as an option for LNG storage and regasification facilities. The goal is to develop a method for using Bayesian Networks in the Risk Analysis of Regasification System of the FSRU, which will convert Fault Trees (FT) into Bayesian Networks (BN) providing more accurate data. Using BN is possible to represent uncertain knowledge and local conditional dependencies. In addition, FT models the failure modes as independent and binary events while BN may model a larger number of states. It is worth noting that BN does not require the determination of cut sets; however, given a failure, it is capable of providing the probability of each possible cut set. This method will provide information to define, in a future study, a maintenance plan based on the Reliability Centered Maintenance. The results intend to clarify the applicability of BN on risk assessment and might improve the risk analysis of a Regasification System FSRU.

scholarly journals Improvements of a Failure Database for Marine Diesel Engines Using the RCM and Simulations

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 104 ◽  
Author(s):  
Francisco Vera-García ◽  
José Antonio Pagán Rubio ◽  
José Hernández Grau ◽  
Daniel Albaladejo Hernández
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
High Speed ◽  
Failure Modes ◽  
Expert Knowledge ◽  
Reliability Centered Maintenance ◽  
Marine Diesel ◽  
Engine Failure ◽  
Generator Sets ◽  
Criticality Analysis

Diesel engines are widely used in marine transportation as a direct connection to the propeller and as electrical principal or auxiliary generator sets. The engine is the most critical piece of equipment on a vessel platform; therefore, the engine’s reliability is paramount in order to optimize safety, life cycle costs, and energy of the boat, and hence, vessel availability. In this paper, the improvements of a failure database used for a four-stroke high-speed marine diesel engine are discussed. This type of engine is normally used in military and civil vessels as the main engine of small patrols and yachts and as an auxiliary generator set (GENSET) for larger vessels. This database was assembled by considering “failure modes, effects, and criticality analysis (FMECA),” as well as an analysis of the symptoms obtained in an engine failure simulator. The FMECA was performed following the methodology of reliability-centered maintenance (RCM), while the engine response against failures was obtained from a failure simulator based on a thermodynamic one-dimensional model created by the authors, which was adjusted and validated with experimental data. The novelty of this work is the methodology applied, which combines expert knowledge of the asset, the RCM methodology, and the failure simulation to obtain an accurate and reliable database for the prediction of failures, which serves as a key element of a diesel engine failure diagnosis system.

ANALISA PERBANDINGAN DALAM RANGKA PEMILIHAN BEBERAPA IP UPSTREAM PROVIDER DI PT. INDOSAT

2018 ◽  
Vol 4 (1) ◽  
pp. 57
Author(s):  
Yuli Anwar ◽  
Dahlar .
Keyword(s):  
Business Strategy ◽  
High Speed ◽  
Human Life ◽  
Sustainable Growth ◽  
The Internet ◽  
Network Service Provider ◽  
High Speed Data ◽  
Telecommunications Services ◽  
The Cost ◽  
Internet Network

Abstract. One of the advances in information technology that now has changed the outlook and human life, business process and business strategy of an institution is the internet. The internet is a very large networks that connected to computers and serves throughout the world in one centralized network. With the internet we can access data and information anytime and anywhere.    As one provider of high-speed data communications services and the pioneer of the internet network service provider in Indonesia that provides integrated services, as well as one of the pioneer development of internet services that provide extensive services in the building and apply it throughout Indonesia. Indosat ready to seize opportunities for sustainable growth of business spectrum are still sprawling Indonesia.    Therefore, Indosat continues to focus on the development of increased efforts to provide the best service for customers of Indosat. Indosat will continue to develop and expand network coverage and a larger investment that the company will achieve excellence in the field of integrated telecommunications services.    Ranking by region of the IP Providers can be seen by grouping IP Providers, and management over IP Providers prefer to choose providers based on where it orginates as an example for the region of the U.S if it will be preferred providers that come from U.S. providers.With the commencement of the internet network optimization start early in 2008 with the selection of the appropriate IP Upstream Provider criteria, it is up to date according to data obtained from Indosat, seen any significant changes to the cost of purchasing capacity of the IP Upstream.    Based on the data obtained that until Q3 or September 2008, the number of IP Upstream Providers that previously there were 20 to 10 IP Upstream Provider, IP Transit Price total decrease of 11% to the price of IP Transit Price / Mbps there is a decrease of 78%, while from the capacity bandwith an increase of 301% capacity from 2008.

Sign in / Sign up

Export Citation Format

Share Document