Showing papers presented at "International Conference on Reliability, Maintainability and Safety in 2016"

Research method for determining preventive maintenance period based on time stress factors

Abstract: Determining the time interval for preventive maintenance is one of the most important duties in programming maintenance guides The purpose of planning the time interval is to keep and restore the reliability of equipment, which means selecting the suitable interval to avoid failures before they occur Existing methods of determining a fixed-time interval always ignore influences such as cumulative failure, overhaul, and repair, which could cause insufficient maintenance or surplus inspection Therefore, making full use of preventative maintenance is a matter of being able to arrange the time interval introduced by time stress factors that could reflect the effect of cumulative failure, repair, overhaul, etc By extending or shortening the time interval according to the specific circumstances of equipment, a modified method of time-interval determination is proposed and verified

Online estimation of state-of-health for lithium ion batteries based on charge curves

Abstract: Usable capacity refers to the maximum capacity in theory that a fully charged battery can release, and is often used as an indicator in state of health (SOH) estimation for lithium ion batteries. The traditional method for measuring usable capacity is mainly based on voltage data in the discharge process with a constant current. However, the discharge current of a lithium ion battery in operation always fluctuates due to load changes, which makes the traditional method difficult for realizing online capacity measurement. To overcome the above problems, a novel approach is proposed in this paper to estimate the usable capacity and SOH of lithium ion batteries based on the charge curve. The time intervals between two voltages and currents during charging are used as the health factors to predict the usable capacity, which is then used to perform the SOH estimation. Experiments are implemented based on data provided by the NASA Ames Prognostics Center of Excellence. Results confirm that the proposed method performs well in online estimation of SOH.

A reliability data fusion method based on improved D-S evidence theory

Abstract: In order to solve the problem of the uncertainty of multi-source reliability data, a reliability data fusion method based on improved D-S evidence theory was presented. The confidence level was calculated by using the angle cosine similarity coefficient and its similarity matrix which is as the weight of the data. After the weights are assigned again, they are fused together with the information. By using this method, the causes of the faults can be determined. A major problem that the fusion results are inconsistent with the intuition when the multi-source data information conflicts each other was solved. A case of reliability analysis of a certain diesel engine was presented as an example to illustrate the proposed method. The results showed that the interference of conflicting evidence can be reduced by introducing a similarity coefficient. Furthermore, the fusion efficiency and precision of the model are increased. Not only can the real reasons for the diesel engine faults be identified accurately, but also the identification efficiency of the whole system can be improved.

High availability verification framework for OpenStack based on fault injection

Abstract: The phenomenon of high availability (HA) is of vital importance in cloud architecture This paper proposes an HA verification framework, called HAVerifier, for OpenStack, a popular open source cloud platform Fault injection technology has been adopted to verify the system's reliability by determining its health status after injecting faults The framework proposed in this paper verifies the availability of services by injecting faults into the different components of OpenStack Service indicators (for example, downtime) are monitored after the faults are injected The collected metrics are compared with the provided service level agreement to verify whether the platform's availability meets the requirements The fault injection steps can be implemented dynamically using the proposed framework, and the faults injected into the platform can be restored without manual intervention Finally, a prototype for this framework is implemented to prove its applicability to verifying the HA of the OpenStack platform

Modeling failure data by 3-parameter Weibull distribution models

Abstract: Many models with three parameters have been developed based on extension or generalization of the Weibull distribution. These models include modified Weibull, Weibull extension, extended Weibull and others. Seven such models are discussed in this paper, in addition to a generalization of the exponential distribution, and a flexible Weibull model with two parameters. These models are more flexible than the usual 2-parameter Weibull, and they are useful for modeling lifetime/failure data with different behaviors such as decreasing, increasing, bathtub-shaped, or even upside-down bathtub-shaped failure rate. In this paper, a procedure for selecting an optimal model for lifetime data analysis is presented based on the plots on Weibull probability paper (WPP). An example is provided to illustrate the procedure and the usefulness of these models. This procedure serves as a guideline for reliability engineers and statisticians when dealing with data modeling.

New forecasting method of closing time for aerospace relay in storage accelerated degradation testing

Abstract: Space relays are affected by many nonlinear elements during storage, and the reason for predicting time series is to achieve nonlinear mapping Combining artificial neural networks and grey system theory, we built a grey artificial neural network (GANN) model The model effectively combined the characteristics of artificial-neural-network nonlinear adaptability and the characteristics of grey theory weakening data sequence volatility integration We predicted the degradation value of the closing time of measured data in a relay accelerated storage test by using a variety of grey models and GANN models By comparing several forecasting methods, the results showed the proposed grey neural network model has higher precision and is more accurate than a single grey model The method also provides new ideas and methods for the life prediction of relay storage acceleration tests

Research on fault injection technology for embedded software based on JTAG interface

Abstract: Fault injection is an effective method for PHM and testability validation. However, with the increasing complexity of structures and functions, and with the promotion of integration levels for airborne prognostics and health management (PHM) and integrated modular avionics (IMA) systems, fault injection is often difficult to use in conventional “plug,” “probe,” or “adaptor plate” methods. Fault injection based on software also presents a bottleneck for engineering applications in terms of controllability and operability. Seeking to solve the problem of applying software fault injection to testability validation, a fault injection technique based on the Joint Test Action Group (JTAG) interface is proposed in this study. The proposed technique is based on the demands of testability validation, takes into account the development trend in avionics of modularization and integration, and adopts aspects of the JTAG boundary-scan technique. Through use of the boundary-scan technique and chip debugging functions, noncontacted hardware fault injection can be realized. Accurate and controllable fault injection of embedded chip pins/functions can then be achieved that satisfies the requirements of fault simulation and injection effect/time. The problems of fault injection implementations for equipment-oriented IMA architecture can thus be overcome, and a new direction for implementing testability validation of airborne PHM and integrated avionics equipment, thereby effectively promoting and ensuring the achievement of testability indices and PHM functions.

Challenges and opportunities of complex equipment operational reliability technology in industrial big data age

Abstract: Large and complex equipment reliability evaluation is extremely dependent on equipment reliability experiment data, maintenance records, and failure data. With the informationalization and intellectualization of equipment (such as CNC machine tools, shield machines, and weaponry), large amounts of data (big data) will be produced during the equipment's operation. Abundant data provide a strong support for equipment operational reliability analysis in the industrial big data age, but also pose a huge challenge for reliability analysis. This paper first explores the opportunities provided by big data to promote the reliability analysis and assessment of complex equipment. Then, we mainly focus on the remaining challenges of equipment operational reliability assessment using the industrial big data method, such as the fact that most of the data reflect an intermediate state (incomplete failure state) of the equipment. We also consider a way to analyze the multiple-states of the equipment operation and correlate the multiple failure modes of the equipment operation using the big data. Moreover, a big data analysis method for calculating the reliability and predicting the residual life of gradual systems is discussed, along with a method for combining the traditional reliability calculation theory with the big data theory. All of these issues provide a significant challenge for the reliability analysis of complex equipment in the big data age.

Model-based safety analyses of embedded system using stateflow

Abstract: Relying on the skill and experience of the engineer, traditional method of safety analyses is subjective and may not guarantee the integrity, consistency and correctness sometimes. In this paper, we first summarize the deficiencies in the safety analysis based on the development of V mode. Then we put forward a new model-based method called VT-mode development. The mode discusses the safety analysis process in detail, meanwhile considering the traditional safety analysis methods. A model-based safety analysis framework is also put forward, which is established on fault model and validation model, combined with the existing foreign scientific research. At last, by modellization and simulation of the fuel engine control system using MATLAB/Simulink/Stateflow, we analyze the system's safety successsfully, verifying the feasibility and effectiveness of this method.

Review on civil aviation safety investment research

Abstract: Maintaining and improving safety has always been the most important thing for civil aviation. Safety investment is an important material guarantee and basis for civil aviation safety. Insufficient investment in safety and irrational structure of safety investment are the causes of accidents in civil aviation. A review of recent research articles related to safety investment was presented and the research status, achievements, existing problems and development prospects were introduced. The construction method of safety investment index system, the cost-benefit analysis of safety investment, and the safety investment decision-making methods were summarized. A framework was proposed to establish a safety investment index system, conduct of cost-benefit analysis, and to assist in the quantitative decision-making of civil aviation safety investment.

Research on imperfect preventive maintenance strategy for turret system of the CNC lathe

Abstract: The turret system is one of the key functional components of the CNC lathe. Therefore it is important that the reliability of the turret system is optimised. In this paper, an imperfect preventive maintenance strategy, based on the Weibull distribution, for the turret system of the CNC lathe is proposed. The restoration and failure intensity increase factors are consistent with a uniform distribution. However, the cost of preventive maintenance increases with the preventive maintenance frequency being increased. Then maintenance time should also be considered. A flexible preventive maintenance model is described in this paper. The aim is to minimize the total maintenance cost overall. The preventive maintenance interval of the model was calculated using the limited reliability value, in order to find the optimal flexible preventive maintenance strategy. Finally, the optimal preventive maintenance results under different cost parameters are discussed.

Accelerative effect analysis of quantitative environmental stress screening

Abstract: Environmental stress screening is an effective method to eliminate the potential defects of electronic products. In order to improve the efficiency and effectiveness of environmental stress screening, the acceleration effect was derived and analyzed based on the quantitative environmental stress screening mathematical principles of GJB/Z34. Then the high-temperature aging, temperature cycling, and random vibration acceleration effect evaluation model was proposed, and the test times under conventional stress and accelerated stress were obtained respectively. Finally, the stress acceleration factor was calculated according to the test time between conventional stress and accelerated stress and an example given which proved that the screening was effective.

A model-driven testing framework based on requirement for embedded software

Abstract: Based on hardware and software integration testing and model driven testing binding requirements, we propose a model based on the needs of embedded software driver initial framework to analyze and identify the needs of embedded systems hardware and software object creation object interaction model, then the model analysis and testing constraints and on the basis of test scenarios, and then establish MARTE model test requirements, test cases accordingly converted into XML model, obtain the initial set of test cases through model transformation algorithm and model checking, and finally the use of intelligent algorithms to obtain objective test set. Expectations for increasing demand for embedded software in line with the degree of automation of the verification process, the verification and running on the target machine's software to achieve high-level functions and needs consistency.

Research of aircraft equipment cabin layout optimization methods based on virtual maintenance

Abstract: Aircraft equipment cabin layout design is an important part of aircraft design It refers to the reasonable arrangement of each piece of equipment and component in a limited space Currently, aircraft equipment cabin maintenance difficulties are common, time-consuming, uneconomical, and are serious maintenance problems In order to improve the accuracy and quality of maintenance design, a virtual maintainability design method is proposed, using DELMIA as a tool to build the virtual environment, which can be used to verify and improve maintainability The maintenance visibility, accessibility, operating space, and working gesture are treated as objective functions The functional constraints and aircraft equipment cabin layout rules are also considered, and are formulated as constraints Thus, a combination algorithm model for maintainability is presented According to the characteristics of the equipment layout problem, a modified particle swarm is used to improve the computational efficiency and solution accuracy Finally, the application of a fighter electronic cabin is studied in detail to illustrate the effectiveness and usefulness of the proposed method The results show that virtual maintainability design can be implemented to solve the layout optimization problem

Bivariate empirical mode decomposition of grinding chatter signals

Abstract: Large numbers of experiments have shown that grinding chatter is one of the major forms of host fault performance in grinding processes. In view of this, more advanced monitoring techniques are required to ensure the high reliability of grinders. The empirical mode decomposition (EMD) technique has shown promise for meeting this requirement. In general, EMD has been limited to processing one-dimensional signals and is unable to deliver the information fusion function required for reliable chatter detection. In this paper, a bivariate EMD (BEMD) was assessed as a grinding condition monitoring technique. Conventional EMD and BEMD were compared by using them to process a simulated chatter signal. The BEMD technique showed a more powerful capability to process non-stationary and non-linear chatter signals. Moreover, BEMD was more effective for extracting features from multiple signals and detecting the phase information of intrinsic mode functions. The instantaneous energy, peak to peak, standard deviation and kurtosis parameters of the signal were able to be used as chatter feature vectors to describe the different vibratory states encountered during grinding. These feature vectors exhibit distinctive behaviors and could be applied as detectors of early grinding chatter.

A reliability optimization allocation method for multifunctional systems using new hybrid particle swarm optimization

Abstract: A reliability optimization allocation method for multifunctional systems using Hybrid Particle Swarm Optimization (HPSO) is proposed in this paper. First, researchers established a mathematical model for system reliability optimization allocation with the constraints of multi-function failure rates. Then, the HPSO was used to solve the optimization allocation model for multifunctional systems. Finally, researchers used an integrated transmission device with five functions as an example. They allocated reliability indexes of five functions by the method proposed in this paper. The result was compared with the results of basic Particle Swarm Optimization (PSO) and the result of Genetic Algorithm (GA). This comparison showed that the method proposed in this paper has a more powerful search capability, higher solving precision, fewer required parameters, better engineering adaptability and operability, and provides a new method of reliability allocation for complex systems with multiple functions.

Reliability assessment of ZPW-2000A track circuit using Bayesian network

Abstract: Nowadays, railway systems are expected to have high reliability, availability, maintainability, and safety. Thousands of ZPW-2000A track circuits are in operation on the mainline and high-speed railway network in China. This paper presents a scheme for reliability assessment of ZPW-2000A track circuit using Bayesian network. First, a fault tree is built based on expert experience and failure investigation. Then, fault tree model of the ZPW-2000A track circuit is converted into Bayesian network. Finally, quantitative analysis based on the Bayesian network is performed, including forward analysis and backward analysis, to calculate the system reliability and recognize vulnerabilities in the system. The validity of the proposed method is fundamental and meaningful for the real-time reliability assessment and condition based maintenance of ZPW-2000A track circuit.

A reliability evaluation methodology of complex systems based on dynamic object oriented Bayesian networks

Abstract: A novel reliability evaluation methodology of complex systems is proposed by using Dynamic Object Oriented Bayesian Networks (DOOBNS). This modeling methodology consists of two main phases: one construction phase for Object Oriented Bayesian Networks (OOBNs) and another construction phase for DOOBNs. In the first phase, the network fragments that have the same structures and parameters are divided into classes, then the classes are encapsulated. OOBN construction is completed according to the relationship among the encapsulated classes. In the second phase, every fragment of DBNs which was constructed by the last phase is encapsulated as a class which is called DOOBN. DOOBN construction is completed according to the relationship between time fragments. The correctness of this methodology is validated by using an all series system, an all voting system, a voting after series system, a series after voting system, a parallel after series system and a series after parallel system. This methodology can model the system from global to local levels, effectively reducing the modeling difficulty, and can take more efficient arithmetic reasoning algorithms.

Reliability allocation for CNC turrets based on fuzzy comprehensive evaluation

Abstract: When it comes to the reliability allocation of Computerized Numerical Control (CNC) turrets, there are two problems. One problem is that the corresponding reliability index is only allocated into each subsystem; another problem is that neglecting the coordination between each subsystem will affect the results of reliability allocation. To solve these two problems a new research method for CNC turret reliability allocation is proposed. It classifies the components of the CNC turret system according to the extent to which these components affect the system's reliability. It takes assembly relationships and CNC turret system sealing as two factors. Along with the components screened out, a reliability block diagram (RBD) is built. The reliability allocation method previously proposed is based on fuzzy comprehensive evaluation. It takes the mean time between failures (MTBF) as the index of allocation and assigns reliability to the components screened out, assembly relationships and sealing. Reliability allocation directly for the components of CNC turrets and research into comprehensive consideration of various factors which affect reliability makes the results of reliability allocation more reasonable, and also provides a specific basis for the design of CNC turrets.

TDR measurement of a solder under temperature cycle test

Abstract: With the decrease in the overall size and the rapid increase in the working frequencies of printed circuit boards, the reliability of solder joints, especially the high frequency signal transmission reliability has become the key factor in system reliability. In this paper, changes in RF impedance of solder joints in a temperature cycling environment was studied using time-domain reflectometry measurements. It was found that with the increase in the temperature cycle, the intermetallic compound layer gradually thickened, and even if no macro damage was found, the RF impedance increased. The transmission reliability of the high frequency signal was degraded.

Maintenance policies for improving the availability of a software-hardware system

Abstract: The present paper deals with the study of a Software-Hardware system under the consideration of software and hardware failures. The concept of degradation is considered for both the Software and Hardware components. For improving the degradation in the performance of Software and Hardware, we have supposed some maintenance policies in the Software as well as Hardware components. To enrich and improve the performance of the software components, the idea of Software rejuvenation has been incorporated. To develop a Markovian model, multi-level Software rejuvenation policy is taken in to consideration. While in the case of Hardware components, maintenance policies for different types of repairs such as corrective and preventive repairs have been considered. Various performance indices of the Software-Hardware system are determined using steady state probabilities. The illustrations are performed to validate the analytical model.

A reliability risk analysis method based on the fuzzy fault tree and fuzzy event tree

Abstract: Based on the analyses systems of fuzzy fault tree and event tree, this paper proposes a method for a reliability risk analysis to mitigate problems associated with risk modeling of fuzzy and uncertain information. Risk event occurrence probabilities were obtained with fuzzy linguistic variables instead of exact values used in fault tree analysis. Quantitative analysis was applied to the fuzzy fault tree to determine the fuzzy importance degree of each basic event, which were then ranked and divided to distinguish the influence of these basic events. Based on this analysis, a fuzzy event tree was constructed and linguistic terms used to evaluate occurrence probabilities and outcomes. Mitigation measures were put forward for risk events and the expected risk magnitudes were calculated under the mitigation strategies. This ensured the mitigation measures were intuitive and accurate. Finally, an application example was illustrated to verify that the proposed method was effective and feasible.

Diagnostic ability validation methods for prognostics and health management systems in complex systems

Abstract: PHM (Prognostics and Health Management) is a key technology in autonomic logistics equipment It is also the newest development in the current equipment system, BIT (Built-In Test), because of its condition monitoring abilities PHM technology marks a transformation from condition monitoring to health management The PHM design philosophy has also been adopted in the development of new generation military and civilian equipment In the complex systems of military and civilian equipment, such as electromechanical systems and flight control systems, the PHM design has been adopted as a new function design The diagnostic capabilities of PHM are its core foundation, and its design level has a direct influence on the overall efficiency of PHM This influence is mainly reflected in its fault detection capabilities, and its comprehensive processing and analysis capabilities In order to validate the PHM fault diagnostic design level, we propose a new diagnostic capability validation method for complex systems Our proposed method is based on testability validation technology, and provides a guideline for technological approaches for PHM diagnostic validation that evaluates the integrity, rationality, and effectiveness of PHM diagnostic capabilities Moreover, our proposed method can expose design defects and weak links, allowing for an iterative optimal design

Research on fault diagnosis training simulation technology based on MCGS

Abstract: Based on MCGS (Monitor and Control Generated System) software a training diagnosis system for a certain kind of equipment is designed and developed. Through analysis of the structure of the equipment composition and working principles of the process a two-dimensional simulation model is established. The model can achieve simple operation training. Using common equipment for fault modeling, a fault tree model is adopted to realize the phenomenon, the reasons for fault diagnosis, and the screening simulation training process. The study shows that the fault diagnosis system based on MCGS software has a short development cycle, low cost and scalability.

Study on the fuzzing test method for industrial supervisory control configuration software based on genetic algorithm

Abstract: Information security of industrial control systems (ICS) is increasingly critical and as a key part of the ICS, the industrial supervisory control configuration software has a great impact on the ICS information security. Accordingly, the current information security issues of the industrial supervisory control configuration software, such as low security protection level, quantities of vulnerabilities, significant harm after attack and lack of effective vulnerability discovery methods, we present a vulnerability discovery method which uses fuzzing test to discover the vulnerabilities in the industrial supervisory control configuration software. First, the information security features of the industrial supervisory control configuration software are analyzed, next the fuzzing test framework is designed according to the information security features obtained, and then the test data generation method based on a Genetic Algorithm (GA) in the fuzzing test is emphatically discussed. The proposed test framework and test data generation method in the fuzzing test can be successfully applied in discovering the vulnerabilities of industrial supervisory control configuration software.

Transformation rules from AADL to improved colored GSPN for integrated modular avionics

Abstract: Although integrated modular avionics (IMA) provides many advantages such as the reduced weight and higher efficiency for system operations, safety problems with correlations of system states come up due to its resource sharing mechanism. Correlations of system states contribute to the fault propagation in IMA systems. In other words, when a shared resource goes into an error state, components which have access to that resource may work in a failed state. Additionally, this process is dynamic during the system running. Model-based method is an adequate approach to analyzing system safety dynamically with correlations of system states. Architecture Analysis and Design Language (AADL) has advantage to model for embedded systems. However, it is quite limited to employ AADL dynamically for analyzing system safety. This paper seeks to translate the AADL models into improved colored GSPN models, which have advantage to simulate with system run-time properties such as time and event occurrence probabilities as well as other properties of system components. Furthermore, the paper focuses on this transformation process without any loss of key modeling elements including those properties mentioned above. Based on this work, subsequent analysis can be conducted. A case study is provided for indicating the application of these transformation rules.

Test case design method targeting environmental fault tolerance for high availability clusters

Abstract: With increasing critical business organizations focusing on the quality of service in cloud applications, high availability (HA) has become critical for the product level cluster of cloud applications. Existing availability evaluation methods or testing projects for cloud platforms, however, cannot sufficiently verify cluster tolerance to various reasonable environmental faults. This paper proposes a test case design method targeting environmental fault tolerance for HA clusters. Test cases are designed considering fault modes and components of a cluster application in diverse scenarios. As a result, the fault tolerance of different components to various reasonable faults can be verified via the proposed method. A case study is conducted on Openstack, a widely used open source software platform for cloud environments, to show the feasibility of using this method.

A highly accelerated life test method for computer keyboards

Abstract: A new method of Highly Accelerated Stress Screen/Life Testing (HASS/HALT) for computer keyboards is introduced and compared with User Information Investigation (UII) from manufacturer, Accelerated Life Testing (ALT), and Normal Stress Reliability Testing (NSRT). The results of the above three lab testing processes all showed good accordance trends with the data from the UII. The failure mechanism shows that a silicone cushion component acts as the spring and the shock absorber when keys are pressed, and acts as a key role to the key function, also decides the life of the key. When the dynamic load of “knocks” (mechanically simulated key presses) increases, the key life decreases, with degradation or failure especially apparent of the silicone cushion. Once a cushion fails, the dynamic shocking forces greatly increase, and the key cap soon breaks. The cushion failure was not a exclusive failure mode observed in the UII, NSRT, ALT and HALT tests, but a crucial one in the Complete Failure Mode Set. The HASS/HALT tests were able to show some quality control features of keyboards within a very short period. The trends corresponded well with real-world failure rate reported by users, ALT and NSRT. This study aids the design of rapid reliability/life testing which is important for product development and efficient quality control. With the help of this method, long-term reliability certification testing can be reduced from months to days.

Failure analysis for micro-short circuit between two pins in printed circuit board assembly

Abstract: Function failure was found successively in one type of smart remote controls when using a period of time With preliminary investigation by electric circuit, low resistance was found between the neighboring pins on failure sample which connected with flexible printed board and rigid printed board, but the pins on good sample were insulated with the others After peeling off the flexible printed board, black materials which looked like migration were found by stereomicroscope and metallography microscope With the help of scanning electron microscope and energy dispersive spectroscope (SEM&EDS), it was detected that the materials mainly contained the elements of Cu (about 50 at%) and S (about 30 at%), and the two short pins were almost connected with the black materials As a result, the black materials which connected to the two pins should be copper sulfide (CuS) and cuprous sulfide (Cu 2 S) The failure process was as the follows Some active sulfide was on the surface of board, with the bias voltage and moisture, the copper on the pads of board was sulfurized and migrated with electrochemical reaction The migration materials which connected to the neighboring pins cause micro-short circuit However, there was no element of Cu on the clean solder mask, and the element of S could not come from the filling material barium sulfate (BaSO 4 ) because barium sulfate were difficult to break down and the element of Ba had not been detected in the black materials Finally, with further investigation for the manufacturing process of the assembly, the element of S was detected on copper foil after soldering with the solder paste which used in the failure sample, but the element of S could not be detected with the other type of solder paste It could conclude that the active sulfide should come from some sulfur-containing materials in the flux of solder paste breaking down in soldering When soldering, the solvent in the flux was difficult to volatilize due to the flexible printed circuit board (FPC) on the top Some sulfur-containing materials in the solvent would decompose to active sulfide So, in order to avoid the failure of micro-short, the solder paste without sulfur containing should be used in soldering

Reliability simulation analysis of satellite products

Abstract: The reliability simulation modeling and analysis of satellite products were studied in this paper. In order to increase the reliability of satellite system, the important products can be design with redundancy structure. Reliability modeling is the basis for satellite reliability engineering. The function and configuration of satellite system is more and more complex, traditional reliability modeling method such as RBD is not applicable. Reliability simulation method can apply to complex system. The reliability simulation method and the basic steps are studied firstly. General reliability simulation models for most products are given, including serial model, parallel model, standby redundancy, voting model. Research is mainly focused on the reliability simulation methods of complex satellite products, such as ring redundancy for TWTAs, more than one redundancy form for gyroscopes, and more than one logic relationship for momentum wheels. Finally, reliability simulation result curves of one satellite system are given as an example.