scholarly journals JUSTIFICATION OPTIMAL PARAMETERS OF REGULATED MAINTENANCE STRATEGY

Author(s):  
S.V. Lienkov ◽  
I.V. Tolok ◽  
G.V. Banzak ◽  
R.Yu. Koltsov ◽  
E.S. Lenkov ◽  
...  

A characteristic feature of complex technical objects for special purposes is the presence in their composition of a large number (tens, hundreds of thousands) of different types component parts that have different levels of reliability, different patterns of their wear and tear processes. This feature requires a more subtle approach to the organization and planning maintenance in the course of their operation. The problem is that in the development of such facilities, all issues related to maintainability and maintenance should be addressed already at the early stages of facility design. If you do not provide in advance the necessary hardware and software for the built-in monitoring of the technical condition (TC) of the facility, do not develop and “build” the maintenance technology into facility, then it will not be possible to realize in the future a possible gain in the reliability of the facility due to maintenance. Since all these issues must be resolved at the stage of object creation (when object does not yet exist), mathematical models of the maintenance process are needed, with the help of which it would be possible to calculate the possible gain in the level of reliability facility due to maintenance, estimate the cost costs required for this. Then, based on such calculations, make a decision on the need for maintenance given type of objects and, if such a decision is made, develop the structure of the maintenance system, choose the most acceptable maintenance strategy, and determine its optimal parameters. The paper shows that the model for the regulated maintenance strategy is an improved version of the already known models and is introduced into the complex model for the purpose of comparative assessment of various maintenance strategies. In addition, it should be borne in mind that in practice, some cases, a regulated maintenance strategy may be preferable to MCC strategies.

Author(s):  
I.V. Tolok ◽  
G.V. Banzak ◽  
E.S. Lenkov ◽  
L.M. Vozikova

A characteristic feature of complex technical objects for special purposes is the presence in their composition of a large number (tens, hundreds of thousands) of various types component parts, which have different levels of reliability, different patterns of their wear and tear processes. This feature requires a more subtle approach to the organization and planning of maintenance in course of their operation. The problem is that in the development of such facilities, all issues related to maintainability and maintenance should be addressed already at the early stages of facility design. If you do not provide in advance the necessary hardware and software for the built-in monitoring of technical condition (TC) of the object, do not develop and "build" the maintenance technology into the object, then it will not be possible to realize in the future a possible gain in the reliability of the object due to maintenance. Since all these issues must be resolved at the stage of object creation (when the object does not yet exist), mathematical models of the maintenance process are needed, with the help of which it would be possible to calculate the possible gain in the level of reliability the facility due to maintenance, to estimate the cost costs required for this. Then, on the basis of such calculations, make a decision on the need for maintenance for this type of objects and, if such a decision is made, develop the structure of the maintenance system, choose the most acceptable maintenance strategy, and determine its optimal parameters. The article shows that the optimal parameters of various maintenance strategies significantly depend on both the reliability and cost structure of the facility and specified requirements for the facility's reliability . The higher the specified value , the more serviced items should be included in the optimal maintenance strategy. It has also been proven that the effectiveness of various maintenance strategies depends significantly on the reliability and cost structure of object. If the distribution of cost restored (including serviced) elements is closely correlated with the distribution of their reliability indicators, difference in effectiveness of different maintenance strategies is reduced. This is clearly seen in the example of Test-2 object, for which the least reliable elements are also the most expensive.


2021 ◽  
Vol 14 (1) ◽  
pp. 40-44
Author(s):  
N. V. Baidakova ◽  
A. V. Afonin ◽  
A. V. Blagochinnov

Deterioration and aging of the technical fleet of thermal power facilities lead to an unpredictable shutdowns of power equipment. Therefore, it is necessary to create a special approach in maintenance and repair programs, taking into account the possibility of predicting the moment of onset of the defect, its development, as well as the time of possible equipment failure. The equipment maintenance system used at the enterprises is based on the collection of retrospective data on defects and failures on the main and auxiliary equipment of the TPP and summarizing statistics on identical or similar equipment samples. Analysis of domestic and foreign methods of maintenance and organization of repair, as well as possibility of their application in modern power engineering is given. In order to create an efficient production asset management system, which addresses the problem of finding a balance between the potential risk of losses associated with both the operation of equipment and the cost of correcting defects, new class systems are now used in the software market, which carry out equipment maintenance based on the forecast. In order to optimize the equipment maintenance system and ensure uninterrupted and reliable operation of the equipment at minimum operating costs, as well as to reduce equipment downtime, unscheduled and emergency operations, it is advisable to use a modern approach to manage both reliability and risk, as well as the cost of asset ownership. This will enable to control the economic efficiency of the use of production assets. The necessity of creation of an algorithm of implementation of repair programs of power equipment base on technical condition for its use in digital power systems is shown. An algorithm is proposed for implementing the repair program of power units of electric power plants, including steam boilers and turbines of thermal power plants, differing by taking into account the technical condition of power equipment, which allows recognizing the defect that has appeared, determining the cause of its occurrence, its evolution and the duration of possible equipment failure. In the developed repair maintenance algorithm, it is proposed to make a transition from statistical empirical assessments of the technical condition of the equipment to objective estimates obtained on the basis of automated technical diagnostics systems and predictive analysis of situations.


Author(s):  
I.V. Tolok ◽  
G.V. Banzak ◽  
E.S. Lenkov ◽  
T.V. Bondarenko

Complex technical objects in modern society are extremely important. Such objects belong to the class of recoverable objects of long-term repeated use. They tend to be expensive and costly to operate. To ensure the required level of reliability during their operation, maintenance is usually carried out, the essence of which is the timely preventive replacement of elements that are in a pre-failure state. A characteristic feature of complex technical objects for special purposes is the presence in their composition of a large number (tens, hundreds of thousands) of different types of component parts that have different levels of reliability, different patterns of their wear and tear processes. This feature requires a more subtle approach to the organization and planning of maintenance during their operation. The problem is that during the development of such facilities, all issues related to maintainability and maintenance should be addressed already at the early stages of facility design. If you do not provide in advance the necessary hardware and software for the built-in monitoring of technical condition (TC) of the object, do not develop and “build” the maintenance technology into the object, then it will not be possible to realize in the future a possible gain in the reliability of object due to maintenance. Since all these issues must be resolved at the stage of object creation (when the object does not yet exist), mathematical models of the maintenance process are needed, with the help of which it would be possible to calculate the possible gain in the level of reliability of facility due to maintenance, to estimate the cost costs required for this. Then, based on such calculations, make a decision on the need for maintenance for this type of objects and, if such a decision is made, develop structure of the maintenance system, choose the most acceptable maintenance strategy, and determine its optimal parameters. In this paper, we study the influence of the coefficient variation on value of the optimal level of maintenance. The work also confirms the general idea that the smaller value of the coefficient variation of random operating time to failure of the serviced elements, greater optimal value of maintenance level should be.


Robotica ◽  
2003 ◽  
Vol 21 (3) ◽  
pp. 313-324 ◽  
Author(s):  
B. Iung ◽  
G. Morel ◽  
J.B. Léger

Quay cranes are particular transportation devices for which operation's safety and CRAMP parameters (Cost, Reliability, Availability, Maintainability, and Productivity) should be fulfilled with regard to a harbor maintenance strategy. The maintenance process is first considered within a holistic modeling framework in order to cope with the current practices of treating strategic, operational and engineering maintenance issues independently without taking into account their interactions within an entire Enterprise System. Proactive maintenance is then highlighted as a new model aiming to globally optimize the components operation parameters throughout three interacting prognosis, diagnosis and monitoring processes. Technical issues related to Intelligent Maintenance System are finally proposed in order to support proactive maintenance operations at the enterprise field level and applied to quay cranes in a particular site within the frame of the European Eureka ‘Robcrane' project.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Alireza Irajpour ◽  
Ali Fallahian-Najafabadi ◽  
Mohammad Ali Mahbod ◽  
Mohammad Karimi

The purpose of this paper is to provide a framework that can identify and evaluate the effectiveness of a given maintenance strategy and to rank components of maintenance system. The framework is developed using DEMATEL method on maintenance strategy as a guideline. To gain a richer understanding of the framework, a questionnaire is constructed and answered by experts. Then the DEMATEL method is applied to analyze the importance of criteria and the casual relations among the criteria are constructed. The scope of the paper is limited to performance measurement of maintenance strategies. It is found that the framework is applicable and useful for the strategic management of the maintenance function. It is observed that the influencing and preferred infrastructures for designing Learning and Training are three components, that is, optimal maintenance, CMMS, and RCM which are interdependent on each other and are the fundamental components to realize the designed goals of maintenance process. This paper provides an overview of research and developments in the measurement of maintenance performance. Many tools and techniques have been developed in other fields. However, the applicability of those tools to maintenance function has never been tried. In that respect this topic is novel. It helps in managing maintenance more effectively.


The article deals with the distribution of agricultural periodicals on the territory of the Russian Em-pire in the early twentieth century. Before that there were practically no publications on the pages of sci-entific magazines. Great emphasis is placed on the analysis of agricultural magazines published before 1917 in the Upper Volga region, namely in Vladimir, Kostroma, Tver and Yaroslavl provinces. Thanks to existed in pre-revolutionary Russian periodicals on agricultural subjects advanced knowledge of agron-omy, agriculture, soil science, horticulture, fruit growing, vegetable growing, winemaking, viticulture, 135 tobacco growing, livestock, poultry, bee-keeping, veterinary medicine, forestry, and hunting, land man-agement, irrigation, horse breeding were promoted. On the basis of statistical data, office documentation and other published sources, the author draws conclusions about the degree of accessibility of agricul-tural periodicals for the population, including the peasantry. Availability of agricultural periodicals largely depended on its price, so the author studied the situation with the cost of the annual subscription fee of these publications. The article investigates the issues of periodicity of agricultural magazines and newspapers, the exact number of such publications, as well as their subject matter. Existence duration of different types of periodicals is analyzed, the main publishers of magazines and newspapers, places of their publication are revealed. A prominent place is given to the publishing activities of agricultural pub-lic organizations and zemstvo self-government bodies. It is concluded that natural process of agricultural knowledge distribution among the population of Russia through publications on the pages of periodicals was disrupted by revolutionary events of 1917.


Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5300
Author(s):  
Antonia Nisioti ◽  
George Loukas ◽  
Stefan Rass ◽  
Emmanouil Panaousis

The use of anti-forensic techniques is a very common practice that stealthy adversaries may deploy to minimise their traces and make the investigation of an incident harder by evading detection and attribution. In this paper, we study the interaction between a cyber forensic Investigator and a strategic Attacker using a game-theoretic framework. This is based on a Bayesian game of incomplete information played on a multi-host cyber forensics investigation graph of actions traversed by both players. The edges of the graph represent players’ actions across different hosts in a network. In alignment with the concept of Bayesian games, we define two Attacker types to represent their ability of deploying anti-forensic techniques to conceal their activities. In this way, our model allows the Investigator to identify the optimal investigating policy taking into consideration the cost and impact of the available actions, while coping with the uncertainty of the Attacker’s type and strategic decisions. To evaluate our model, we construct a realistic case study based on threat reports and data extracted from the MITRE ATT&CK STIX repository, Common Vulnerability Scoring System (CVSS), and interviews with cyber-security practitioners. We use the case study to compare the performance of the proposed method against two other investigative methods and three different types of Attackers.


2015 ◽  
Vol 8 (2/3) ◽  
pp. 262-283 ◽  
Author(s):  
Alona Mykhaylenko ◽  
Ágnes Motika ◽  
Brian Vejrum Waehrens ◽  
Dmitrij Slepniov

Purpose – The purpose of this paper is to advance the understanding of factors that affect offshoring performance results. To do so, this paper focuses on the access to location-specific advantages, rather than solely on the properties of the offshoring company, its strategy or environment. Assuming that different levels of synergy may exist between particular offshoring strategic decisions (choosing offshore outsourcing or captive offshoring and the type of function) and different offshoring advantages, this work advocates that the actual fact of realization of certain offshoring advantages (getting or not getting access to them) is a more reliable predictor of offshoring success. Design/methodology/approach – A set of hypotheses derived from the extant literature is tested on the data from a quantitative survey of 1,143 Scandinavian firms. Findings – The paper demonstrates that different governance modes and types of offshored function indeed provide different levels of access to different types of location-specific offshoring advantages. This difference may help to explain the ambiguity of offshoring initiatives performance results. Research limitations/implications – Limitations of the work include using only the offshoring strategy elements and only their limited variety as factors potentially influencing access to offshoring advantages. Also, the findings are limited to Scandinavian companies. Originality/value – The paper introduces a new concept of access, which can help to more reliably predict performance outcomes of offshoring initiatives. Recommendations are also provided to practitioners dealing with offshoring initiatives.


2001 ◽  
Vol 38 (02) ◽  
pp. 386-406 ◽  
Author(s):  
Bernd Heidergott

We consider a multicomponent maintenance system controlled by an age replacement policy: when one of the components fails, it is immediately replaced; all components older than a threshold age θ are preventively replaced. Costs are associated with each maintenance action, such as replacement after failure or preventive replacement. We derive a weak derivative estimator for the derivative of the cost performance with respect to θ. The technique is quite general and can be applied to many other threshold optimization problems in maintenance. The estimator is easy to implement and considerably increases the efficiency of a Robbins-Monro type of stochastic approximation algorithm. The paper is self-contained in the sense that it includes a proof of the correctness of the weak derivative estimation algorithm.


2021 ◽  
Vol 13 (7) ◽  
pp. 3850
Author(s):  
Ting Liu ◽  
Gabriel Lodewijks

This paper proposed a scheme design for Sydney’s frontport check-in system, which completes check-in and baggage drop-off at Sydney’s Circular Quay, and transports the baggage to Sydney Kingsford Smith Airport by waterway, and provided a strengths, weaknesses, opportunities and threats (SWOT) analysis of Sydney’s frontport check-in system. Using the process method of quality management, the frontport check-in process was divided into three sub-processes: baggage consignment, baggage packing and transportation, and airport baggage handling. The eight key elements of each sub-process such as input, output, resources, and methods, etc. were discussed, the key factors influencing the cost of baggage transportation were analyzed, and the cost control measures such as adopting economic speed, reducing fuel consumption of the main engine, improving the ship loading rate, and raising loading and unloading efficiency were proposed. At the same time, two different types of baggage transportation ships and other parameters that affect the cost such as the number of berths, ships, lifting machineries, and the yard area were analyzed and calculated through calculation cases. This scheme is a beneficial addition to the existing in-town check-in system.


Sign in / Sign up

Export Citation Format

Share Document