Barnert Tomasz, Kosmowski Kazimierz T., Śliwiński Marcin
Knowledge-based functional safety management using ProSIL software
In the article the ProSIL software for computer aided functional safety management is presented. The software consists of three modules for the determination of the required SIL level (ProSILen) and verification of the SIL level (ProSILver). In the ProSIL the calibrated knowledge-based risk graph method for determining the required safety integrity level (SIL) of the safety functions identified in hazard analysis is implemented. The SILs are then verified for safety-related control and protection systems implementing relevant functions with regard to random failures and potential systematic failures. The assessment methods are compatible with international standards IEC 61508 and IEC 61511. Some current challenges and methodological issues concerning knowledge-based functional safety management in life cycle are also discussed.[full text]
Berg Heinz Peter
Critical infrastructure and resilience goals
Critical infrastructure risks pose a special problem for all countries. The companies that own these infrastructures operate in competitive and regulated environments. However, it is neither practical nor possible to protect critical infrastructures from all hazards. For the government, the continuity of these infrastructures is critical to many of its fundamental missions: economic stability and growth, national security, public safety, and quality of life. In that context resilience has become an important factor to fulfil the task of the critical infrastructure protection. Thus, the development of a framework to establish resilience goals could be helpful.[full text]
Duarte, José Caldeira
A unified approach to maintenance management supported by statistical techniques
Maintenance activities represent an increasingly high cost in any manufacturing system or in different types of structures. Its achievement or not has a major impact on availability of equipment or structures. Nowadays cost reduction, minimizing downtime and ensuring reliability levels are central objectives in any sector of industrial activity and maintenance is observed as an important service. To achieve these goals, decision support systems should be available, optimizing the exploration and maintenance plans and ensuring companies meeting their goals. In this paper a global model for maintenance management based on the reliability theory and other statistical techniques, is presented. This model is being applied to several industrial sectors and some prototypes have been developed. The need for a maintenance database is also highlighted. [full text]
Eid Mohamed, Souza de Cursi Eduardo, El Hami Abdelkhalak
A topological model to assess networks connectivity and reliability
The acceleration of the interconnectivity of networks of all sorts brings to the front scene the issue of networks performance measure. Recently, one observed an accelerating course towards quantitative probabilistic models to describe and assess networks’ Connectivity, as being the main vector of performance. However, modelling realistic networks is still far from being satisfactorily achieved using quantitative probabilistic models.
On the other hand, little room had been lift to exploring the potential of topological models to develop qualitative and semi- quantitative models in order to assess networks connectivity. In this paper, we are exploring the potential of the topological modelling. The proposed model is based on describing the nodepair connectivity using binary scalars of different orders (tensors). Preliminary results of our explorations sounded very promoting.[full text]
Grabski Franciszek
Application of perturbed semi-Markov processes in reliability
The paper is concerned with the application of perturbed semi-Markov (SM) processes in reliability problems. There are two kinds of perturbed SM processes presented in the paper. First of them was defined by Shpak and the second one was introduced by Pavlov and Ushakov. Shpak’s concept of perturbed SM is applied for calculating the approximate reliability function of many tasks operation process and Pavlov and Ushakov concept of that one is used to obtain the approximate reliability function of a repairable cold standby system with a switch.
[full text]
Kolowrocki Krzysztof, Soszynska-Budny Joanna
On safety of critical infrastructures modeling with application to port oil transportation system
A new approach to safety investigations of multistate complex systems with dependent components at variable operation conditions called critical infrastructures is proposed. The safety function of the critical infrastructure system is defined and determined for an exemplary “m out of l” critical infrastructure. In the developed model, it is assumed that the system components have the multistate exponential safety functions with interdependent departures rates from the subsets of the safety states. The approach is adapted to safety prediction of oil piping transportation system operating at a maritime port. [full text]
Kuligowska Ewa,
Monte Carlo simulation for reliability assessment and optimization of an object subjected to varying operation conditions
This paper presents the computer simulation technique related to the reliability of an object under variable operation conditions. The considered object operation process is modelled using semi-Markov processes and its reliability is analysed by application of the conditional reliability functions in its different operation states. The backgrounds and procedures of the Monte Carlo simulation method application to an object at variable condition reliability analysis are proposed and applied to reliability evaluation of an exemplary object. Consequently, under arbitrarily assumed the parameters of this exemplary object operation process and its conditional reliability functions, using the proposed Monte Carlo simulation procedures, the transient probabilities of the exemplary object operation process at the particular operation states and its unconditional reliability function are determined. Further, the linear programming is introduced and proposed to reliability optimization of an object at variable operation conditions and the optimal transient probabilities of the exemplary object operation process at the particular operation states and its optimal unconditional reliability function are determined. Finally, some practical suggestions on the modification of the exemplary object operation process improving its reliability are proposed.
[full text]
Mazurkiewicz Jacek,
Softcomputing approach to discrete transport system analysis
The paper presents an approach to complex analysis of sophisticated Discrete Transport Systems (DTS) using softcomputing. The proposed methodology can efficiently substitute the classical approach especially since dependability parameters of the system are mostly approximated by experts instead of classical sources of data. On the other hand we can try to combine reliability and functional aspects. The paper describes the multicriteria scientific field of the Discrete Transport Systems and shows the way how the softcomputing can be in use in the sensible way. Moreover, results of the numerical experiment performed on a test case scenario related to the reliability and functional aspects using proposed methodology are given. The approach allows reducing the problem of assumptions of reliability distributions and – this way – seems to be very interesting for real systems management and tuning. [full text]

Milazzo Maria Francesca
Approaches to industrial risk assessment coupled with catastrophic natural phenomena
The aim of this contribution is to focus attention on a new emerging risk known in the literature as Na-Tech risk (Natural-Technological risk). Na-Tech are technological accidents triggered by natural events, these are of particular interest for high risk industries. The magnitude of such an event is much broader than that related to a technological accident and its management is much more complex. Adequate preparedness, proper emergency planning and effective response are crucial for the prevention and mitigation of the consequences of Na-Techs This contribution gives a general overview of the methodologies, that are currently being developed, in order to integrate these types of scenarios into the conventional quantitative risk analysis for chemical and process industry. [full text]

Pietrucha-Urbanik Katarzyna, Rak Janusz Ryszard, Tchórzewska-Cieślak Barbara,
Safety analysis of water supply systems including protection barriers
Water quality control from the perspective of water supply system users’ safety contributed to create drinking water production and quality control procedures. Contemporary risk hazard analysis should be performed on the stage of production, distribution and storage of tap water. Sequences of undesirable events are considered in the so-called waterworks chain series. This leads to critical control points and gives the ability to provide current control over the processes in the collective water supply system, as well as of their combinations and mutual interactions. Methodology of water consumers protection against incidental pollutions was shown. Algorithm concerning identification of critical control points – CCP was developed .The rules of safety related system into drinking water production have been shown. Also risk assessment using the tree event method was presented. [full text]

Stanclik Miłosz, Walkowiak Tomasz
Risk in systems with virtualization – test case analysis

The paper presents an approach to risk analysis of exemplar test case information systems. Authors point out
the common practice to implement virtualization and put away security considerations for future[5]. The overview of virtualization techniques, focusing on server virtualization is given. Next, authors present risk analysis of exemplar GIS system. First of all identification of threats is taken out focusing on virtualization aspects, but it also includes common threats for both that could have a significant impact on safety when using a virtualization. The risk assessment for the test case system was performed using qualitative method. Assessment of the likelihood and magnitude of impact of identified risks was performed on the basis of the expert’s knowledge and experience. The obtained results were used to develop risk rankings, which indicate the risks that need special attention when designing and managing a virtual system.[full text]

Vaidogas Egidijus Rytas, Kisezauskiene Lina, JuoceviciusVirmantas
An assessment of reliability of a blast wall using limited statistical information on blast loading
A design of a blast wall is considered. Methods of structural reliability analysis and quantitative risk assessment are applied to the design. The basic idea of this design is to apply a probability of failure of cladding components as a criterion of damage to the cladding. This probability is used as an estimate of the proportion of cladding components destroyed by an explosion. The cladding failure probability is estimated by quantifying and propagating uncertainties related to a mechanical model of cladding and elements of the statistical sample containing records of blast loading. It is demonstrated how to estimate the cladding failure probability when the size of this sample is small from the standpoint of classical statistics. The case study included in the paper considers a design of a cladding for a blast wall to be deployed for protecting a fuel tank against an explosion of a railroad tank car. [full text]
Woch Maria, Bońkowski Tomasz, Kłysz Sylwester
Combat survivability of hit aircraft
The paper is provides a preliminary breakdown susceptibility analysis for an aircraft PZL-130 ORLIK TC II in combat conditions. An analysis of breakdown forms and consequences for aircraft sections and installations in battle conditions including probability of being shot down when hit was made. The article presents a theoretical outline for calculation methods on aircraft kill probability in case of being shot, depending on critical element configuration and number of hits. The probability figures have been calculated for a specific model describing the aircraft PZL-130 ORLIK TC II. As a result of the conducted analysis it was possible to determine, for a specified weapon caliber, probabilities and effects of receiving combat damage.[full text]