Selective maintenance of multi-state series systems considering maintenance quality uncertainty and failure effects

2021 ◽  
pp. 095440892199693
Author(s):  
Xinlong Li ◽  
Yan Ran ◽  
Genbao Zhang ◽  
Hui Yu
Keyword(s):  
Decision Maker ◽  
Engineering Practice ◽  
Quality Uncertainty ◽  
Equipment Operation ◽  
System Maintenance ◽  
Selective Maintenance ◽  
Maintenance Decision ◽  
Series Systems ◽  
Maintenance Model

In order to improve the lifetime and reliability of equipment operation stage, it is necessary to carry out maintenance for components. The typical selective maintenance model does not consider the maintenance quality uncertainty and the failure effects, which may make the decision-maker overestimates the reliability of completing the next task after system maintenance, resulting in incorrect maintenance decision and prone to serious consequences of failure. In this paper, the potential discrepancy between the target maintenance quality and the actual maintenance quality of the decision maker is considered. At the same time, a multi-state FMECA is proposed to measure the failure effects under different states. Finally, the selective maintenance model of the multi-state series systems is established and solved by the genetic algorithm. The results show that considering the effect of component failure and the uncertainty of maintenance quality has an influence on maintenance decision. The maintenance decision made in this way is more consistent with the engineering practice.

scholarly journals Optimal Selective Maintenance Decision-Making for Consecutive-Mission Systems with Variable Durations and Limited Maintenance Time

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Huiying Gao ◽  
Xiaoqiang Zhang ◽  
Xiaoqiang Yang ◽  
Bo Zheng
Keyword(s):  
Genetic Algorithm ◽  
Optimization Problem ◽  
Great Influence ◽  
Maintenance Strategy ◽  
Maintenance Time ◽  
Selective Maintenance ◽  
Maintenance Decision ◽  
Set Up ◽  
Maintenance Model ◽  
Repairable Components

Maintenance is inevitable for repairable components or systems in modern industries. Since the maintenance effectiveness has a great influence on the subsequent operations and in addition, different maintenance options are possible for the components of the system during the break between any two successive missions, the optimal selective maintenance strategy needs to be determined for a system performing successive missions. A number of selective maintenance models were set up on the basis that the durations of each mission are predetermined, the maintenance time is negligible, and the states of the components at the end of the previous mission can be accurately obtained. However, in the actual industrial and military missions, these premises may not always hold. In this paper, a novel selective maintenance model under uncertainties and limited maintenance time is proposed to improve these deficiencies. The genetic algorithm is selected to solve the optimization problem, and an illustrative example is presented to demonstrate the proposed method. The optimal selective maintenance decision without the constraint of maintenance time is used for comparison.

Simulation of vibration piercing of pipe blank at press

2020 ◽  
Vol 76 (11) ◽  
pp. 1128-1138
Author(s):  
S. R. Rakhmanov
Keyword(s):  
High Frequency ◽  
Deformation Zone ◽  
Pipe Blank ◽  
Equipment Operation ◽  
Metal Deformation ◽  
Technological Tool ◽  
High Frequency Vibrations ◽  
Pipe Blanks ◽  
Wave Phenomena

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.

The influence of unintentional radio interference on the equipment operation quality of satellite radio navigation systems consumers

2020 ◽  
pp. 165-170
Keyword(s):  
Underlying Surface ◽  
Navigation Systems ◽  
Signal Attenuation ◽  
Radio Navigation ◽  
Equipment Operation ◽  
Atmospheric Noise ◽  
Detection Mode ◽  
Signal Mode ◽  
Cosmic Noise

The analysis an influence of reflections from the underlying surface, atmospheric noise, the Earth’s surface, cosmic noise and signal attenuation of the signal the atmosphere, as well as the flight dynamics of the aircraft (AC) on the signal/noise ratio and, accordingly, on the accuracy of AC navigation definitions by using consumer equipment of the satellite radio navigation systems. The analysis an influence of reflections from the underlying surface on the equipment operation quality of the satellite radio navigation systems consumers is carried out by using the Beckman model, in accordance with the earth’s surface appears to consist of flat faces with an arbitrary slope. It is noted that reflections from the underlying surface have a greater effect on the quality of functioning of the consumer equipment of the satellite radio navigation systems in the tracking signal mode than in the detection mode. In this case, the influence of reflections increases with decreasing flight altitude and an increase in the angle of heel of the AC in the direction of the navigation spacecraft.

Multifactor mathematical model of criticality of welding process of products from aluminum- magnesium alloys

2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina
Keyword(s):  
Mathematical Model ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Welding Process ◽  
Welding Equipment ◽  
Equipment Operation ◽  
Aluminum Magnesium Alloys ◽  
Aluminum Magnesium Alloy ◽  
Welding Materials

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]

A Survey of the Present State of Friction Modelling in the Analytical and Numerical Investigation of Brake Noise Generation

1999 ◽  
Author(s):  
Jörg Wallaschek ◽  
Karl-Heinz Hach ◽  
Ulrich Stolz ◽  
Parimal Mody
Keyword(s):  
Friction And Wear ◽  
Numerical Models ◽  
Engineering Practice ◽  
Noise Generation ◽  
Noise And Vibration ◽  
Levels Of Detail ◽  
Key Issues ◽  
Brake Noise ◽  
Automotive Brake

Abstract Noise and vibration have become key issues in the design of automotive braking systems. Efforts to improve present day braking systems must take noise and vibration behaviour into account. Good knowledge of the mechanisms involved in the generation of brake noise has thus become an important competitive factor in the design of automotive brake systems. The present paper summarizes some facts and hypotheses concerning the generation of brake noise. First the different brake noise phenomena are classified. Then several approaches, including models of various levels of detail which have been suggested to explain the root causes of brake noise generation are discussed in detail. It will be pointed out that friction and wear processes at the interface of brake pad and rotor play an important role in the understanding of brake noise generation. Unfortunately, our present day knowledge on these processes is quite limited. Further research of basic processes is still needed to improve the quality of analytical and numerical models of friction and wear processes, before reliable predictions of brake noise generation become possible. Based on a discussion of simple models frequently used in engineering practice, guidelines for further research in tribological modelling of the interface processes in pad/rotor interaction will be formulated.

Competitive Entry of Information Goods Under Quality Uncertainty

2021 ◽  
pp. 1-20
Author(s):  
Zan Zhang ◽  
Guofang Nan ◽  
Minqiang Li ◽  
Yong Tan
Keyword(s):  
Product Quality ◽  
New Product ◽  
High Price ◽  
Quality Uncertainty ◽  
Information Goods ◽  
Consumer Uncertainty ◽  
Willingness To Adopt ◽  
Marketing Activities ◽  
Very High

When confronted with a new product, consumers often find it difficult to predict how it will perform, and such uncertainty reduces consumers’ willingness to adopt the product. In this paper, we consider a market whereby consumers decide when and which product to buy, given that they know the product quality of the incumbent but are uncertain about that of the entrant. We investigate how consumer uncertainty about product quality affects firms’ behavior-based pricing and customer acquisition and retention dynamics. Using a two-period vertical model, we find that, under high-end encroachment, an increase in consumer uncertainty reduces the entrant’s profit and hurts the incumbent’s profit when the quality differential between the products is relatively small, whereas, under low-end encroachment, increasing uncertainty not only benefits the incumbent but also can favor the entrant. An important implication for entrants is that the marketing activities, which aim to reduce consumer uncertainty about product functionalities, may fail to improve profitability. We also find that the entrant lowers the price for uninformed customers and raises the price for repeat buyers under high-end encroachment but lowers the price for all customers under low-end encroachment. We further examine the subsidy strategy and show that, when the entrant’s product has a significant quality advantage and consumer uncertainty is high but not very high, the optimal strategy for the entrant is to acquire all consumers who do not buy from the incumbent by providing subsidies and to drop the low-valuation customers by means of a high price after their uncertainty is resolved.

To Charter or Not to Charter: What Questions Should We Ask, and What Will the Answers Tell Us?

2014 ◽  
Vol 84 (3) ◽  
pp. 341-364 ◽  
Author(s):  
Harry Brighouse ◽  
Gina Schouten
Keyword(s):  
Charter Schools ◽  
Lived Experience ◽  
School Board ◽  
Decision Maker ◽  
Charter School ◽  
School Performance ◽  
Board Member ◽  
New School ◽  
School Board Member

In this essay, Harry Brighouse and Gina Schouten outline four standards for judging whether to support the chartering of a new school within a given jurisdiction. The authors pose the following questions to a hypothetical school board member: Will the school increase equality of opportunity? Will it benefit the least-advantaged students in the jurisdiction? Will it improve the preparation of democratically competent citizens? Will it improve the quality of the daily, lived experience of the students? Brighouse and Schouten suggest that most of the evidence concerning charter school performance focuses on just the students within the schools, without addressing a charter school's effect on students who do not attend. They argue that a full evaluation requires both kinds of evidence and that these questions are the four standards that should guide both the decision maker and researchers gathering evidence on the effects of charter schools.

A Dynamic Reliability-Centered Maintenance Analysis Method for Natural Gas Compressor Station Based on Diagnostic and Prognostic Technology

2015 ◽  
Vol 138 (6) ◽  
Author(s):  
Dengji Zhou ◽  
Huisheng Zhang ◽  
Yi-Guang Li ◽  
Shilie Weng
Keyword(s):  
Natural Gas ◽  
Preventive Maintenance ◽  
Condition Based Maintenance ◽  
Equipment Management ◽  
Analysis Method ◽  
Dynamic Reliability ◽  
Maintenance Schedule ◽  
Reliability Centered Maintenance ◽  
Maintenance Decision ◽  
Maintenance Model

The availability requirement of natural gas compressors is high. Thus, current maintenance architecture, combined periodical maintenance and simple condition based maintenance, should be improved. In this paper, a new maintenance method, dynamic reliability-centered maintenance (DRCM), is proposed for equipment management. It aims at expanding the application of reliability-centered maintenance (RCM) in maintenance schedule making to preventive maintenance decision-making online and seems suitable for maintenance of natural gas compressor stations. A decision diagram and a maintenance model are developed for DRCM. Then, three application cases of DRCM for actual natural gas compressor stations are shown to validate this new method.

Auctioning IT Contracts with Renegotiable Scope

2021 ◽  
Author(s):  
He Huang ◽  
Zhipeng Li ◽  
De Liu ◽  
Hongyan Xu
Keyword(s):  
Bargaining Power ◽  
It Outsourcing ◽  
Quality Uncertainty ◽  
Strategic Substitutes ◽  
Fixed Price ◽  
Ex Post ◽  
Information Rent ◽  
High Investment ◽  
Two Measures

Motivated by challenges facing IT procurement, this paper studies a hybrid procurement model in which a reverse auction of a fixed-price IT outsourcing contract may be followed by renegotiation to extend the contract’s scope. In this model, the buyer balances the needs to incentivize noncontractible vendor investment and to curb the winning vendor’s information rent by choosing the initial project scope and the buyer’s investment in the quality of the project. We find that a buyer may benefit from inducing ex post renegotiation to motivate vendor investment, especially when the winning vendor has high bargaining power and the quality uncertainty is low. Broadening the initial scope reduces information rent but leaves little room for ex post renegotiation and, hence, discourages vendor investment, whereas increasing the buyer’s investment has opposite effects. Interestingly, the two measures can be strategic substitutes or complements depending on the likelihood of the renegotiation and the two parties’ bargaining powers. The buyer may strategically set a low initial project scope and high investment to incentivize renegotiation and vendor investment, which may explain why many IT outsourcing projects start small and allow expansions. Our findings also generate several testable predictions for IT outsourcing. This paper was accepted by Kartik Hosanagar, information systems.

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