Solojentsev E.D., Karasev V.V.
SCIENTIFIC SCHOOL «MODELING AND ANALYSIS OF SAFETY AND RISK IN COMPLEX SYSTEMS» - ACTUAL APPROACH TO ACTUAL
 

Alexej Chovanec
PREDICTION OF NO – FAILURE SYSTEM OPERATION

Alexej Chovanec
PREDICTION OF THE SYSTEM AVAILABILITY USING SIMULATION MODELING
The article deals with the possibility of system availability prediction using the simulation modelling. The system availability determined with system faultlessness and system maintainability is expressed by various parameters of mean time between the failures and the mean time of single elements repair. The system simulations are carried out with more parameters MTBF and MTTR, the results of the simulation course gives a real idea about the system behaviour in time and about changes of the values of asymptotic system availability factor.

Anton Ambrozy, Alexej Chovanec
COST OPTIMIZATION FOR REALISATION OF MAINTENANCE COST
This paper deals with optimal control interval determination using minimization the financial costs. It clears conceptual, mathematical and simulation model of the problem solution. It enumerates and evaluates results of the simulation.

Jozef Bucha, Alexej Chovanec
SIMULATION OF FTA IN SIMULINK
This paper deals with possibility of simulation of reliability block diagrams, failure trees analysis as a time dependent analysis using Matlab/Simulnk

Himanshu Dutt Sharma, Bangale Shreyas Madhukarao
SIMULATED ELECTRICAL NETWORK APPROACH (SENA) TO HARD OPTIMIZATION PROBLEMS
A novel method is proposed for hard optimization type of problem wherein an exact optimal solution is increasingly difficult in terms of run time and memory requirements. Especially for the cases when search graph has higher number of nodes and more number of paths, which increase as factorial of node number. This is based on Simulated Electrical Network Approach (SENA) proposed here, in which the graph is modeled as an electrical network and current distribution is found which is used as a directive for search decisions. The proposed algorithm results in an approximate method that achieves average accuracy of 99.89% to reach close to the most optimal path that is found by ranking all possible paths. Conversely, it can eliminate on average 99.89%
paths in polynomial time from consideration if one requires finding the most optimal one.

Milan Holicke
RISK ASSESSMENT AND OPTIMIZATION OF ROAD TUNNELS
Probabilistic methods of risk optimization are applied to specify the most effective arrangements of road tunnels. The total consequences of alternative arrangements are assessed using Bayesian networks supplemented by decision and utility nodes. It appears that the optimization may provide valuable information for a rational decision concerning number of escape routes. Discount rate seems to affect the total consequences and the optimum arrangements of the tunnels more significantly than number of escape routes.
 

Melnikov V.A.
MODEL OF A RELIABILITY FOR STRUCTURAL - COMPLICATED SYSTEMS, INCLUDING MULTYSTATE ELEMENTS
The problem of development of Boolean models of a reliability for systems, including elements with many states is considered on the basis of multivalued logic, algebra of trains, algebra of groups of incompatible events and classical logistic-probabilistic method (LPM). The inexpediency of development of Boolean models of a reliability on the basis of multivalued logic is displayed. The numerical examples demonstrating serviceability of LPM and their new possibilities are demonstrated. The perspective of development of methods of an evaluation of effectiveness of operation at different levels of operation rate by formulation of a set of different tasks, solved by the same LPM is underlined

Solojentsev E.D.
SCENARIO MANAGEMENT OF RISKS OF ACCIDENTS AND CATASTROPHES IN BUSINESS AND ENGINEERING
The stages of development of Management and Risk are described. The scenario management of risks of accidents and catastrophes in complex systems on the stages of designing, debugging and exploitation test and exploitation itself are considered. In the scenario management of accidents and catastrophes risks the personnel and the General designer are taken into account. The uniform approach to the modelling of risks in technical, economic and organisational systems is presented on the basis of substantial description of a SCENARIO of an accident or a catastrophe, and then the construction of models of the risk for the purpose of analysis and management. As the intellectual core for the risk quantitative evaluation and analysis and the scenario management of accidents and catastrophes risk, LP-methods and risk LP-models with groups of incompatible events are used.

Romney B. Duffey, John W. Saull
MANAGING AND MEASURING RISK IN TECHNOLOGICAL SYSTEMS
Safety Management is intended to create order out of disorder, to reduce the “information entropy”, for the purpose of improved safety. Our purpose here and now is to try to introduce some predictability and insight into the risk or occurrence of apparently random events, where a general risk prediction we adopt a fundamental must be testable against the world’s existing data. The risk management issues are clear, given the classic features of major human involvement and contribution to accidents, errors and outcomes occurring with modern technological systems. Prior incidents and prior knowledge and experience must be fully incorporated or learned from. If we do not know where we are on the learning curve, we also do not know the probability of such an
event, and we have no objective measure of the “safety culture”. Emphasis on defining and finding so-called “lack of safety culture” has resulted in an extensive and detailed study of the safety management and process safety of many global corporations. We utilize the concepts adopted in thermodynamics and Information Theory to establish the information entropy as a finite, physically based and useful measure of risk in technological systems. The results that we demonstrate show that the risk is dynamic, and can be utilized for management and predictive risk analysis purposes.

Jiri Stodola
TRAFFIC ACCIDENTAS INFORMATION SYSTEM AND RISK CRASH EVALUATION
This article analyses the traffic accident rate on roads and highways and possibilities of risk evaluation related to traffic accident occurrence based on factors that were the causes of accidents. A new term – risk of traffic accident occurrence is a product of probability of accident occurrence and its impacts. The results are presented by way of example that uses selected statistical data of the Czech Republic traffic accident rate between 1993 - 2001. The article provides a brief methodological procedure of evaluation of the traffic accident rate using the risk of traffic accident occurrence.

I. Kozine, N.J. Duijm, H. Hagen
THE SEVESO II DIRECTIVE AND DANISH ACTIVITIES SUPPORTING ITS APPLICATION IN SOME EASTERN EUROPEAN COUNTRIES

K. Lauridsen, I. Kozine, A. Amendola, M. Fiori
EU ADVANCES IN IDENTIFYING SOURCES OF UNCERTAINTY IN RISK ANALYSES
This paper presents the scope and some main results of a European project on the ASSessment of Uncertainties in Risk ANalysis of Chemical Establishments (ASSURANCE). The project aims at identifying the uncertainties associated with risk analysis of major industrial hazards and assessing the way these uncertainties can affect the final outcome of risk studies and of the relevant decisions based on that outcome. In order to achieve this goal, a number of benchmark exercises/case studies have been performed by the partners and the results were analysed in a modular and structured way. A reference plant served as the basis for a realistic description of these case studies. For this particular project an ammonia storage plant was selected, consisting of cryogenic and pressurised storage tanks, together with import loading/unloading facilities and the relevant piping. This installation was analysed independently by each partner, using common input data and boundary conditions, but different methods, tools and assumptions. The results were then compared and discrepancies identified, discussed and explained.
 

Henry K Moskatov
ADAPTATION, LEARNING AND INHERENT SAFETY OF 2ND GENERATION AIRSHIPS
Inherent safety of the new generation airships, based on some fundamental laws of Space, is discussed in some detail. An algorithm is proposed to analyze risks, resulting from hazards not compensated by “inherent safety”. Then a thoroughly verified statistical model of learning is used to evaluate results of airship flight testing-the probability of mission success and its confidence limit. The results can be used as a part of evidence for airship airworthiness certification.

Yu. Paramonov, A. Kuznetsov
PLANNING OF INSPECTION PROGRAM OF FATIGUE-PRONE AIRFRAME
To keep the fatigue ageing failure probability of an aircraft fleet on or below the certain level an inspection program is appointed to discover fatigue cracks before they decrease the residual strength of the airframe lower the level allowed by regulations. In this article the Minimax approach with the use one- and two-parametric Monte Carlo modelling for calculating failure probability in the interval between inspections is offered.

Finkelstein M.S.
STOCHASTIC APPROACH TO SAFETY AT SEA ASSESSMENT
A general approach for analysing spatial survival in the plane is suggested. Two types of harmful random events are considered: points with fixed coordinates and moving points. A small normally or tangentially oriented interval is moving along a fixed route in the plane, crossing points of initial Poisson random processes. Each crossing leads to termination of the process with a given probability. The probability of passing the route without termination is derived. A safety at sea application is discussed.
 

Novosyolov A.
MEASURING RISK
Problem of representation of human preferences among uncertain outcomes by functionals (risk measures) is being considered in the paper. Some known risk measures are presented: expected utility, distorted probability and value-at-risk. Properties of the measures are stated and interrelations between them are established. A number of methods for obtaining new risk measures from known ones are also proposed: calculating mixtures and extremal values over given families of risk measures.

Solojentsev E.D., Rybakov A.V.
RESEARCHES IN IDENTIFICATION OF LOGICAL AND PROBABILISTIC RISK MODELS WITH GROUPS OF INCOMPATIBLE EVENTS
In this paper the results of the researches in identification of the logical and probabilistic (LP) risk models with groups of incompatible events are presented. The dependence of the criterion function on several parameters has been investigated. The parameters include: the total number of optimisations, the amplitude of parameters increments, the initial value of the criterion function (CF), the choice of identical or different amplitudes of increments for different parameters, objects risks distribution. An effective technology of defining the global extreme in the identification of LP-risk model for the calculation time, appreciable to practice has been suggested.

Renzo Righini, Enrique Montiel
A NEW METHOD FOR THE APPLICATION OF RAMS TECHNIQUES TO QUALITY ASSURANCE (QA)
The application of RAMS techniques in all the phases of the lifecycle of each type of installation will surely guarantee its adequate exploitation in terms of production continuity and quality of the obtained products in the respect of prefixed constraints on the security of the working staff, safety and environment impact. In this frame, a particular importance must be attributed to the use of those techniques as support to quality assurance applied in the planning and building phases of the installation and of the products obtained by it. The present paper will include a short description of a method for the application of those techniques in this phase of the lifecycle and of the results that may be obtained by its application in shoes manufacturing, in particular those types where the technical requirements are higher, as it is the cases of certified products like “safety” footwear.

Igor Safonov
ASPECT-ORIENTED SOFTWARE RELIABILITY ENGINEERING
Aspect-Oriented Approach to Software Development allows us effectively to effectively extract, evaluate and solve the main problem of contemporary tendency in Information Technology (particularly, in an Application Software) – a unification is alternated by a personalization. Increasing customer concerns about Performance, Quality, Reliability and Security (PQRS concept) can be satisfied only by symbiosis synergy of adequate models, techniques and tools on all stages of the Software lifecycle. We propose original methodology, formal models and simple methods of Software Reliability Engineering based on our many years experience of concern separation and aspect orientation in Software Development for Specialized Computers, Business Application and
Government Institutions.

Brian Bailey, Igor Safonov
TRUST ENGINEERING AND RISK MANAGEMENT FOR SAFETY OF METROPOLIS AND MEGALOPOLIS CITIZENS
The article describes the problems and solutions in the field of safety enhancement in emergency situations of the complex urban agglomerations and analyses of the most actual problem for all metropolises and megalopolises – terrorism, proposing the rational models and techniques of counterterrorism strategy, based on knowledge and experience.

Lev V. Utkin, Thomas Augustin
RISK ANALYSIS ON THE BASIS OF PARTIAL INFORMATION ABOUT QUANTILES
Risk analysis under partial information about probability distributions of states of nature is studied. An efficient method is proposed for a case when initial information is elicited from experts in the form of interval quantiles of an unknown probability distribution. This method reduces a difficult to handle non-linear optimisation problem for computing the optimal action to a simple linear one. A numerical example illustrates the proposed approach.

Lev V. Utkin, Sergey P. Shaburov
RISK ANALYSIS ON THE BASIS OF JUDGMENTS SUPPLIED BY UNKNOWN EXPERTS
The development of a system requires fulfilling the available standards of reliability and safety. Due to possible complexity of the system, its parameters often are determined by experts whose judgements are usually imprecise and unreliable due to the limited precision of human assessments. Therefore, an approach for computing probabilities of expert judgments and for analysing the risk of decision about satisfying the parameters to standards of reliability and safety is proposed in the paper. A numerical example considering a microprocessor system of central train control illustrates the proposed approach.

David VALIS
CONTRIBUTION TO CONSEQUENCES ANALYSIS USING FUZZY PROBABILITY
This article deals both with dependability and risk analysis from a complex point of view. Both these fields seem to be similar in many aspects, but unfortunately no congruence in sources of basic characteristics has been reached, yet. Statistical files are often very vague in terms of monitoring dependability measures or risk factors. There is a great need to use another point of view to describe these factors. One of those measures and fragments of risk or dependability are consequences both in terms of an event occurrence and failure occurrence. By using a new approach, better interconnection between these both fields and deeper applicability would be provided. A theory of fuzzy probability could be one of these new methods that could facilitate modelling of quantitative factors.

David VALIS
CONTRIBUTION TO STOCHASTIC METHODS OF COMPLEX SYSTEMS RISK ANALYSIS
The paper deals with risk assessment of complex systems. As we investigate situations regarding military applications the fragments of risk management are very important for us. Risk and dependability characteristics of military battle equipment have the same importance for us as those measures which have to serve to perform battle missions itself. There is no time on the battle field to solve unpredicted and unexpected situations caused by high risk level or unreliability which might lead to loss of both equipment and crew. Due to high level of risk we face on the battlefield many systems have to be robust enough or have to be redundant to succeed.