The Aim of the paper is to create a method for including information on censorship for the purpose of adjusting the estimates of the S-N diagram of composite materials. Censored items are such items that did not fail by the end of testing, for which a certain operation time has been registered. It must be noted that, currently, researchers often ignore the operation time data of the items that did not fail by the end of testing, which does not appear to be justified in terms of cost saving and reliability of statistical conclusions. Censorship information is very important in terms of assessing durability. It only needs the right tool to use it.

The proposed Method consists in bootstrapping-based simulation, a method from the group of computer-intensive methods. In the process of the method’s development, the previously used approaches (for instance, as regards metals) were considered. In the examined example of the method’s application, the data was taken from literary sources.

Results. The paper shows an example of fatigue testing conducted by the authors that produced a large number of censored items. The results obtained using the method were compared with real data. It is shown that the quality of statistical estimation improves with the use of the method. The paper sets forth certain observations regarding the mechanical testing tool for quality control. The source of data dispersion associated with fatigue testing is discussed.

Conclusions. The application of the method will help include the information on censored items in the estimation of the S-N diagram. For scientists who are involved in the experimental research of the fatigue resistance of composite materials, the suggested method might prove to be quite useful. It takes into consideration the characteristic features of the strength analysis of composite materials (large properties dispersion and absence of unlimited fatigue range). The method will allow taking onto account an important, but not always so far used information on the items that operated a certain number of cycles, but did not fail.

Hierarchy analysis developed by Thomas Saaty is a closed logical structure that uses simple and well-substantiated rules that allow solving multicriterial problems that include both quantitative, and qualitative factors, whereby the quantitative factors can differ in terms of their dimensionality. The method is based on problem decomposition and its representation as a hierarchical arrangement, which allows including into such hierarchy all the knowledge the decision-maker has regarding the problem at hand and subsequent processing of decision-makers’ judgements. As the result, the relative degree of the interaction between the elements of such hierarchy can be identified and later quantified. Hierarchy analysis includes the procedure of multiple judgement synthesis, criteria priority definition and rating of the compared alternatives. The method’s significant limitation consists in the requirement of coherence of pairwise comparison matrices for correct definition of the weights of compared alternatives. The Aim of the paper is to examine a non-conventional method of solving the problem of alternative ratings estimation based on their pairwise comparisons that arises in the process of expert preference analysis in various fields of research. Approaches are discussed to the generation of pairwise comparison matrices taking into consideration the problem of coherence of such matrices and expert competence estimation.

Method. The methods of hierarchy analysis, models and methods of the Markovian process theory were used.

Result. The paper suggested a method of using the transitive graph of a Markovian process as part of expert ranking of items of a certain parent entity subject to the competence and qualification of the experts involved in the pairwise comparison. It is proposed to use steady-state probabilities of a Markovian process as the correlation of priorities (weights) of the compared items. The paper sets forth an algorithm for constructing the final scale of comparison taking into consideration the experts’ level of competence.

Conclusion. The decision procedures, in which the experts are expected to choose the best alternatives out of the allowable set, are quite frequently used in a variety of fields for the purpose of estimation and objective priority definition, etc. The described method can be applied not only for comparing items, but also for solving more complicated problems of expert group estimation, i.e., planning and management, prediction, etc. The use of the method contributes to the objectivity of analysis, when comparing alternatives, taking into consideration various aspects of their consequences, as well as the decision-maker’s attitude to such consequences. The suggested model-based approach allows the decision-maker identifying and adjusting his/her preferences and, consequently, choosing the decisions according to such preferences, avoiding logical errors in long and complex reasoning chains. This approach can be used in group decision-making, description of the procedures that compensate a specific expert’s insufficient knowledge by using information provided by the other experts.

Any process of technical product development may involve dependability testing. If in the course of operation, the recovery of an entity after a failure is the norm, then test plans of types NRect, NRecR, NNoRect и NNoRecR are normally used, where N is the number of tested same-type entities; t is the testing time of each of the N entities; R is the number of failures; Rec (NoRec) is the characteristic of the plan that indicates that the entity’s operability after each failure within the testing time is recovered (not recovered). Normally, NRect and NRecR indicate that, in the process of testing, failures are recovered immediately. In order not to confuse plans NRect, NRecR, NNoRect and NNoRecR with test plans with long recovery times, let us denote the latter as NRec!t, NRec!R, NNoRec!t and NNoRec!R respectively. Let us simplify the problem description and require, for test plans of types NRec!t, NRec!R, NNoRec!t and NNoRec!R, the fulfilment of condition D = R, where D is the number of recoveries, i.e. after the conclusion of testing, at the moment of time t, the recovery of entities continues until the last of R failed entities is recovered. We will denote such test plans NRec!t(D=R), NRec!R(D=R), NNoRec!t(D=R) and NNoRec!R(D=R). As the dependability model, an exponential distribution is adopted. Steady-state availability is normally defined as the composite dependability indicator of recoverable entities. Finding efficient estimates is one of the primary goals of the dependability theory. Since the 1960s, Russian scientific literature has featured next to no research dedicated to the properties of steady-state availability estimates. The best known work in the steady-state availability estimates for a NRecR test plan is in the book: Beletsky B.R. [Dependability theory of radio engineering systems (mathematical foundations). Study guide for colleges]. Moscow: Sovetskoye radio; 1978. This paper makes up for this deficiency. In order to identify the efficient steady-state availability estimate out of infinite many, first, an estimate efficiency comparison criterion is to be constructed. The paper

Aims to construct a simple criterion of steady-state availability estimation for test plans with long recovery times and identify the efficient estimate out of the available ones using the constructed criterion.

Methods of research. The efficient estimate was found using integral numerical characteristics of the accuracy of estimate, i.e., the sum square of the displacement of the expected realization of an estimate from the considered parameters of the distribution laws.

Conclusions. The authors constructed simple criteria of efficiency of steady-state availability estimation for test plans with long recovery time (case of N≥1). Estimate G₃=(1+VR/S(R1))^-1 is bias-efficient out of those available for test plans of types NRec!t(D=R) and NNoRec!t(D=R). Conventional estimate G₁=(1+ V/S)^-1 is bias-efficient out of those available for test plans of types NRec!R(D=R) and NNoRec!R(D=R).

Aim. In healthcare field there exist different types of uncertainty due to medical error generated by human and technologies. In general the crisp value generate loss of precision and inaccuracy about result and therefore the available data is not sufficient to assessed clinical process up to desired degree of accuracy. Therefore fuzzy set theory play as an important and advance role in accuracy of results in healthcare related problems.

Methods. Here for more accuracy of result, we use functional fuzzy numbers in this paper. This study uses a new fuzzy fault tree analysis for patient safety risk modelling in healthcare. In this paper we will use level (λ, ρ) interval-valued triangular fuzzy number, their functional, t-norm operation and centre of gravity defuzzification method to evaluate fuzzy failure probability and estimate reliability of system. The effectiveness of these methods is illustrated by an example related to healthcare problems and then we analyse the result obtained with the other existing techniques. Tanaka et al.’s approach has been used to give the rank of basic events of the considered problems. Also, we use functional of fuzzy numbers to analyse the change in fuzzy failure probability.

Results. The paper examines the application of the failure tree, t-norm and functional fuzzy numbers in the context of interval-valued triangular fuzzy numbers. The research examined two types of healthcare-specific problems and the corresponding defuzzification techniques for the purpose of reliability analysis using the existing methods. The authors concluded that t-norm is not associated with significant accumulation and identified how a functional fuzzy number affects reliability. Similarly, using the V index method, the least critical events were found for each system.

Aim. The long-lasting discussion of the dependability-related terminology is evidence of the relevance of the subject matter and, at the same time, identifies difficulties associated with finding middle-ground solutions. This article aims to eliminate the shortcomings associated with the application of the conventional, yet insufficiently substantiated terms in the GOST 27.002-2015 interstate standard. Correct understanding and use of terms are of great significance.

Methods. The paper lays down the requirements for the used terminology in terms of internal logical consistency and identifies specific terms, the use of which violates such requirements. Several terms from the standard underwent a logical and terminological analysis based on statutory requirements and the semantic meanings of such terms.

 Findings and conclusions. The paper states that the perfection of terms, definitions and basic concepts comes down to the fact that a standard shall not contain synonyms, homonyms and terms previously adopted in other standards with new or modified definitions. The terminological analysis helped to identify the terms whose use is unjustified. It was noted that the term “dependability” is clearly defined as a property, whose content and meaning are set forth with adequate substantiation. However, other definitions of dependability in the standard are not substantiated. Several cases of the use of terms that do not comply with the proposed requirements were considered, e.g., “dependability estimation”, “dependability indicators estimation”, “state of item”, etc.

The Aim of this paper is to evaluate the advantages of digital twin technology as compared with the conventional approaches to the design of a vital two-channel system.

Methods. The system is described with a Markovian model. This model allows defining the quantitative safety characteristics if the system is affected by right-side failures.

Results. The system’s primary quantitative safety indicators were identified as the mean time to wrong-side failure and mean time to right-side failure along with the quantitative relations of the prime and additional costs for a batch of products.

Conclusion. Transforming the initial item into a system with digital twins allows significantly reducing the rate of wrong-side failures. This effect may be obtained not only with the use of digital twins, but also as the result of the system transitioning into the state of right-side failure in each event of discrepancy betwin the initial item and/or the digital twins. It has been established that the mean time to right-side failure under such conditions is not less than the mean time to failure of the initial item. That means that highly efficient measures for safety improvement allow maintaining the system dependability at a level not lower than that of the initial item. The introduction of digital twins into a system is a new, not yet tested way of ensuring system safety. The decision on the benefits of additional costs is taken by the customer and system developer together. At the same time, it must be taken into consideration that in case of large batches of manufactured technical systems, the effect of additional costs is reduced and the effect of significantly improved safety is maintained.

Aim. This article continues the series of studies aimed at improving the aptitude screening of commercial aviation personnel. The socionic characteristics of a human operator define his/her work with information flows, and their significance is the higher, the greater is the time shortage they have to deal with as part of their professional activities, therefore, in this paper, those characteristics were examined as professionally important qualities of both a pilot, and an air traffic controller. The task consisted in evaluating the socionic characteristics of male and female control room specialists, who have successfully completed aptitude screening in commercial aviation, identifying the presence or absence of differences between the obtained results. Additionally, for the sake of comparison, the research covered the socionic characteristics of males and females, whose professional activities have nothing to do with technology. In total, the study includes data of over 3116 tested persons.

Methods. The 5-th modification of the MM-1 socionic test developed by the Saint Petersburg State University of Civil Aviation was used as the psychodiagnostic method for estimating constituent socionic characteristics. The obtained samples were primarily compared using Pearson’s chi-squared test. The results were also processed using correlation analysis.

Results. The paper presents socionic portraits,i.e. the distribution of the dominating components of the human socionic model among various samples, socionic models of various professional groups (human socionic model for a typical member of a sample), as well as graphical data per individual psychological dichotomies: “extraversion – introversion”, “logic – ethics”, “sensorics – intuition”, “rationality – irrationality”.

Conclusions. The identified differences between the studied samples are primarily professional in their nature, i.e. comparing samples of individuals from the same professional group and approximately the same age, but different gender, in no case reliable differences were identified. Thus, no fundamental gender-specific differences were identified by the socionic psychodiagnostic method used as part of this work. However, the analysis of a number of Russian and foreign sources dedicated to gender differences suggests that improving the reliability of aptitude screening of aviation specialists requires further research involving the evaluation of the differences in the expression of the necessary professionally significant qualities of control room specialists, not by criterion of biological sex, but rather in accordance with the identified gender-related personality type.

Aim. JSC RZD is one of the largest and most advanced companies in Russia who actively deploys and uses best practices in asset and risk management. In 2010, the railway industry initiated the project for the management of resources, risks and dependability at lifecycle stages of railway facilities (URRAN) that is currently under way. The aims of this paper are to overview the asset management tasks covered by URRAN; examine the marketed IT tools designed to address such problems; present the progress of the URRAN project in terms of process automation implemented by JSC RZD in light of the international best practice and the specificity of the Company.

Methods. The preparation of this paper involved empirical and theoretical research. The authors analysed the URRAN project’s package of guidelines and regulations, public information on the globally available software products enabling asset management, as well as the program documentation of the EKP URRAN automated system. They analysed the functionalities and and engineering solutions used in the development of this automated system. The results of the EKP URRAN deployment and practical application by units and branches of JSC RZD were evaluated.

Results. Asset management involves using Enterprise Asset Management Systems (EAMS) specially designed to suit the needs of specific companies or mass-produced “out-of-the-box” systems, e.g. SAP ERP, IBM MAXIMO, ABB AbilityТМ and SimeoTM that are examined in the paper. The EKP URRAN implements a single information space that is a decision support tool for the asset management system as it possesses the required regulatory and procedural resources, hardware and software assets intended for comprehensive management of assets and processes for the purpose of efficient railway service. In the future, the EKP URRAN is to become part of the Digital Platform for Risk and Traffic Safety Management deployed in JSC RZD and will comprise modules that implement dynamic predictive analytics models for the purpose of predicting undesirable events involving infrastructure and rolling stock that may disrupt traffic safety.

Conclusions. Further development of the EKP URRAN will soon provide all levels of company management with an efficient tool that allows, in the context of limited resources, making substantiated managerial decisions and rational investment allocation. The EKP URRAN is an asset of JSC RZD designed to be used by the managers and specialists of various JSC RZD units. It can be implemented as a standalone IT product for the purpose of developing and deploying an asset management system in various railway companies.