a This paper presents a reliability analysis method on repairable system with standby structure based on goal oriented (GO) methodology. Firstly, a new combination of GO operator, which is composed of a new logical GO operator named Type 18A operator and a new auxiliary GO operator named Type 20 operator, is created to represent standby mode. The availability formula of standby equipment with translation exception is deduced based on Markov process theory. Then, the application method of combination of GO operator for standby mode and the analysis process of repairable system with standby structure based on GO method are proposed. Thirdly, this new combination of GO operator is applied in availability analysis of the hydraulic oil supply system of power-shift steering transmission. Finally, the results obtained by the new GO method are compared with the results of fault tree analysis, Monte Carlo simulation, GO methods using Type 2 operator and Type 18 operator to represent the standby mode, respectively. And the comparison results show that this new GO method is applicable and reasonable for reliability analysis of repairable system with standby structure. All in all, this paper provides guidance for reliability analysis of repairable systems with standby structure.

GO methodology is a success-oriented method for system reliability analysis. There are Multiple-Input, which contain control signal, oil provided and electrical signal et.al and MultiFunction Components (MIMFC) in some repairable systems, such as double-action variable displacement pump, multiple directional control valve, and hydraulic coupler etc. Because existing 17 basic GO operators in GO methodology can’t describe these MIMFCs accurately, it is a problem to adopt existing GO methodology to conduct the reliability analysis for these systems with MIMFC. In this paper, firstly a new GO operator combination, which is composed of a new function GO operator and a new auxiliary GO operator, is created to represent MIMFC. The new function GO operator named as Type 22 operator is created to represent MIMFC itself, and the auxiliary GO operator named as Type 15B operator is created to represent multi-conditions control signals of MIMFC. Then, quantitative calculation formulas of new GO operator combination are derived based on logical relationships among inputs, outputs, and component itself. Thirdly, this new GO operator combination is applied for the first time in steady availability analysis and qualitative analysis of the fan drive system of a Power-shift Steering Transmission. Finally, the results obtained by the method in this paper are compared with the result of Fault Tree Analysis (FTA) and result of Monte Carlo simulation, and the comparison results show that this new GO operator combination is usable and correct for reliability analysis of repairable system with MIMFC, and it has more advantageous in the aspects of building system model and quantitative analysis. Meantime, this paper provides guidance for reliability analysis of other repairable systems with MIMFC.

This paper presents a new approach for the reliability analysis of vehicle systems by considering typical characteristics based on goal-oriented methodology. First, solutions are proposed for vehicle systems with multiple fault modes, a standby structure at any position, a multiple-input closed-loop feedback link, multiple functions, and multiple conditions for the goal-oriented method. Then, a two-level goal-oriented model and the new rules of goal-oriented operation for such vehicle systems are proposed. Furthermore, the quantitative method and the qualitative method are improved. In addition, the analysis process for these vehicle systems based on the new goal-oriented method is formulated. Finally, this new goal-oriented methodology is applied in the dynamic availability analysis and qualitative analysis of the power-shift steering transmission for a heavy military vehicle. In order to verify the feasibility, the advantages, and the correctness of the new goal-oriented methodology, the results are compared with those from fault tree analysis and Monte Carlo simulations. In general, this study not only improves the theory of the goal-oriented method and widens the application of the goal-oriented method but also provides a new reliability analysis method for such vehicle systems. In addition, the analysis process of the new goal-oriented method shows that the goal-oriented method has advantages in system reliability modeling and system reliability analysis for vehicle systems.

This paper proposes a new GO method for repairable systems with multiple unstable operation states. First, multi-state signal flow and multi-state GO operator are defined, respectively. And the formula for calculating state probability of unit with multiple unstable operation states is deduced based on Markov theory. Furthermore, a new function GO operator named Type 19 is created to describe the unit stabilizing property. And its GO operation formulas for reliability analysis are deduced. On this basis, the reliability analysis process of multi-state repairable systems based on the new GO method is formulated. Then, this new GO method is applied in reliability analysis of Hydraulic Oil Supply System of a heavy vehicle. In order to verify the feasibility, advantage and reasonability of the new GO method, its analysis result is compared with those of FTA and the existing GO method for two-state repairable systems. All in all, this paper not only improves the theory of GO method, and widens the application of GO method, but also provides a new approach for reliability analysis of multi-state repairable systems.