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.
