Systems reliability analysis in variable operation conditions

The semi-markov model of the system operation process is proposed and its selected parameters are defined. There are found reliability and risk characteristics of the multi-state series- “m out of k ” system. Next, the joint model of the semi-markov system operation process and the considered multi-state system reliability and risk is constructed. The asymptotic approach to reliability and risk evaluation of this system in its operation process is proposed as well

Complex technical systems safety prediction

There are presented general safety analytical models of complex multistate technical systems related to their operation processes. They are the integrated general models of complex technical systems, linking their multistate safety models and their operation processes models and considering variable at the different operation states safety structures and their components safety parameters. The conditional safety functions at the system particular operation states and independent of the system particular operation states the unconditional safety function and the risk function of the complex technical systems are defined. These joint models of the safety and the variable in time system operation processes are constructed for multistate series, parallel, “m out of n”, consecutive “m out of n: F”, series-parallel, parallel-series, series-“m out of k”, “mi out of li”-series, series-consecutive “m out of k: F” and consecutive “mi out of li: F”-series systems. The joint models are applied to determining safety characteristics of these systems related to their varying in time safety structures and their components safety characteristics. Under the assumption that the considered systems are exponential, the unconditional safety functions of these systems are determined. The proposed models and methods are applied to the safety analysis, evaluation and prediction of the one subsystem of the port grain transportation system related to varying in time their operation processes, structures and components safety parameters

Modelling safety of multistate systems with ageing components

Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. The exemplary safety structures of the multistate systems with ageing components are defined and their safety functions are determined. As a particular case, the safety functions of the considered multistate systems composed of components having exponential safety functions are determined. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics of the exemplary series, parallel, “m out of n”, consecutive “m out of n: F”, series-parallel, parallel-series and “m out of l”-series systems are presented as well

Multi-state system safety analysis in changing operation conditions

W artykule zaproponowano wielostanowe podejście do oceny bezpieczeństwa systemów oraz zastosowane są procesy semi-markova do modelowania ich procesu eksploatacji. Zdefiniowano funkcję bezpieczeństwa systemu i funkcja ryzyka systemu. Zaproponowano również podejście do rozwiązania bardzo ważnego, praktycznego problemu powiązania bezpieczeństwa systemów z ich procesami eksploatacji. Zastosowanie proponowanej metody zostało przedstawione na przykładzie oceny bezpieczeństwa portowego systemu transportu paliwa.A multi-state approach to estimation of the systems' safety is proposed and a semi-markov processes for their operation modelling are applied. A system safety function and a system risk function are defined. The paper offers an approach to the solution of a practically very important problem of linking the systems' safety and their operation processes. Application of the proposed method is illustrated in the safety evaluation of the port oil transportation system

Reliability and risk evaluation of a container gantry crane at variable operation conditions

The joint model of the system operation process and the system multi-state reliability is applied to the reliability and risk evaluation of the container gantry crane. The container gantry crane is described and its operation process unknown parameters are identified on the basis of real statistical data. The mean values of the container gantry crane operation process unconditional sojourn times in particular operation states are found and applied to determining this process transient probabilities in these states. The container gantry crane different reliability structures in various its operation states are fixed and their conditional reliability functions on the basis of data coming from experts are approximately determined. Finally, after applying earlier estimated transient probabilities and system conditional reliability functions in particular operation states the unconditional reliability function, the mean values and standard deviations of the container gantry crane lifetimes in particular reliability states, risk function and the moment when the risk exceeds a critical value are found. he joint model of the system operation process and the system multi-state reliability is applied to the reliability and risk evaluation of the container gantry crane. The container gantry crane is described and its operation process unknown parameters are identified on the basis of real statistical data. The mean values of the container gantry crane operation process unconditional sojourn times in particular operation states are found and applied to determining this process transient probabilities in these states. The container gantry crane different reliability structures in various its operation states are fixed and their conditional reliability functions on the basis of data coming from experts are approximately determined. Finally, after applying earlier estimated transient probabilities and system conditional reliability functions in particular operation states the unconditional reliability function, the mean values and standard deviations of the container gantry crane lifetimes in particular reliability states, risk function and the moment when the risk exceeds a critical value are found

Reliability, risk and availability based optimization of complex technical systems operation processes. Part 1, Theoretical backgrounds

A convenient new tool for solving the problem of reliability and availability evaluation and optimization of complex technical systems is presented. Linking a semi-markov modeling of the system operation processes with a multi-state approach to system reliability and availability analysis is proposed to construct the joint general model of reliability and availability of complex technical systems in variable operation conditions. This joint model and a linear programming is proposed to complex technical systems reliability and availability evaluation and optimization respectively

Safety and risk evaluation of Stena Baltica ferry in variable operation conditions

Basic safety structures of multi-state systems of components with degrading safety states related to their variable operation conditions are defined. For these systems the conditional and unconditional multi-state safety functions are determined. A semi-markov process for the considered systems operation modelling is applied. Further, the paper offers an approach to the solution of a practically important problem of linking the multi-state systems safety models and the systems operation processes models. Theoretical definitions and results are illustrated by the example of their application in the safety and risk evaluation of the Stena Baltica ferry operating at the Baltic Sea. The ferry transportation system has been considered in varying in time operation conditions. The system safety structure and its components safety functions were changing in variable operation conditions

Optimization of port oil transportation system operation processes

W artykule zintegrowany ogólny model niezawodności złożonych systemów technicznych w zmiennych warunkach eksploatacyjnych, łączący wielostanowe podejście do analizy niezawodności systemów z modelem semi-markowskim ich procesu eksploatacji oraz programowanie liniowe zastosowane są w transporcie morskim do optymalizacji procesu eksploatacji skutkującej podwyższeniem niezawodności portowego rurociągowego systemu transportu paliwa.The joint general model of reliability of complex technical systems in variable operation conditions linking a semi-markov modeling of the system operation processes with a multi-state approach to system reliability analysis and linear programming are applied in maritime industry to operation process optimization improving reliability of a port piping oil transportation system

The Evaluation of Reliability and Availability of a Port Grain Transportation System

Zaproponowano użycie granicznych funkcji do oceny niezawodności i gotowości systemów oraz zastosowanie procesów Semi-Markova do modelowania ich procesu eksploatacji. Analizowano też podejście do rozwiązania bardzo ważnego, praktycznego problemu powiązania niezawodności systemów z ich procesem eksploatacji. Zastosowanie przedstawionej metody omówiono na przykładzie oceny niezawodności i gotowości portowego systemu transportu zboża.The paper proposes the use of the limit reliability functions in the systems' reliability and availability evaluation and semi-markov processes application for their operation modelling. The paper offers an approach to the solution of a practically very important problem of linking the systems' reliability and their operation processes. An application of the proposed method is illustrated in the evaluation of reliability, risk and availability of the port grain transportation system

Optimization of complex technical systems operation processes

W artykule przedstawiono nowe praktyczne narzędzie do rozwiązania zagadnienia optymalizacji procesu eksploatacji i niezawodności złożonych systemów technicznych. Wykorzystano zintegrowany ogólny model niezawodności złożonych systemów technicznych w zmiennych warunkach eksploatacyjnych, łączący wielostanowe podejście do analizy niezawodności systemów z modelem semi-markowskim ich procesu eksploatacji. Ten łączny model oraz programowanie liniowe zaproponowane są jako narzędzie do optymalizacji procesów eksploatacji złożonych systemów technicznych skutkującej maksymalizacją średnich czasów przebywania systemów w podzbiorach stanów niezawodnościowych.A convenient new tool for solving the problem of reliability and availability evaluation and optimisation of complex technical systems is presented. Linking a semi-Markov modelling of the system operation processes with a multi-state approach to system reliability analysis is proposed to construct the joint general model of the reliability of complex technical systems in variable operation conditions. This joint model and linear programming are proposed for complex technical systems for the optimisation and maximisation the system lifetimes in the reliability state subsets