System Reliability and Metrics of Reliability

Journal of Electronic Packaging, 2014

Intermittent failures and no fault found (NFF) phenomena are a concern in electronic systems because of their unpredictable nature and irregular occurrence. They can impose significant costs for companies, damage the reputation of a company, or be catastrophic in systems such as nuclear plants or avionics. Intermittent failures in systems can be attributed to hardware failures or software failures. In order to diagnose and mitigate the intermittent failures in systems, the nature and the root cause of these failures have to be understood. In this paper we have reviewed the current literature concerning intermittent failures and have a comprehensive study on how these failures happen, how to detect them and how to mitigate them.

IEEE Transactions on Reliability, 1982

three modules were s-independent, then when one module State University of New York, Binghamton is temporarily faulty, there is a good chance that other modules will function correctly. If, however, there is some s-dependence, then the chances of two modules being Key Words-s-Dependence, Intermittent failures, Transient failures, faulty at the same time is increased, thereby increasing the Reliability analysis, s-Dependency in redundant modules. chance of the output of the voter being incorrect. In order to consider such s-dependence during reliabili-Purpose: Advance the state of the art ty calculations, it is necessary to quantify s-dependence. Special math needed for explanations: Probability Such a measure should relate well to the physical Special math needed to use results: Same phenomena and should keep the analysis tractable. Results useful to: Reliability engineers, Fault-tolerant system designers This paper examines some measures of s-dependence and theoreticians between modules. After presenting a suitably defined Abstract-In reliability calculation, the general assumption is to measure, its relationship with the system parameters is inregard the behavior of redundant systems as (statistically) s-independent. vestigated. When the parameters of a single module are This considerably simplifies the mathematics involved, but limits the available along with an estimated value of a s-dependence usefulness of the results as s-dependence can appreciably impact the measure (by empirical methods), then the module system reliability. This paper introduces two measures, using linear cor-parameters with s-dependence can be obtained and used to relation, to describe the s-dependence of intermittent failures. One measure relates to the linear correlation for the entire period during which compt re n orderrto obtin uempiricelat faults are active in different modules; the other measure relates to the for a s-dependence measure, multi-module experimental closeness in time of the instants faults become active in different modules. systems have to be studied; the fault behavior with respect Characteristics and their relationship with reliability and fault processes to time can be recorded by using self-checking. of these measures are considered. Irreversible processes corresponding to permanent failures are examined.

Journal of Electrical and Electronic Engineering, 2015

Numerical methods, particularly finite element methods, are widely used in solving different problems. Since these methods are approximate, having a real understanding of the distribution of errors is extremely important. With the increasing number of users, the number of cause dfailuresin creases by their fault. In this article we will discuss per formance evaluation system, the performance evaluation of computer and communication systems for quality research that is finding its profit goals for the number of ways to predict the behavior of the system. One of the main parameters in determining the performance evaluation is reliability and because some complex systems cannot be easily modeled by hybrid methods (RBD), we use Markov method.

IEEE Transactions on Instrumentation and Measurement, 2000

In critical digital designs such as aerospace or safety equipment, radiation-induced upset events (single-event effects or SEEs) can produce adverse effects, and therefore, the ability to compare the sensitivity of various proposed solutions is desirable. As custom-hardened microprocessor solutions can be very costly, the reliability of various commercial off-the-shelf (COTS) processors can be evaluated to see if there is a commercially available microprocessor or microprocessor-type intellectual property (IP) with adequate robustness for the specific application. Most existing approaches for the measurement of this robustness of the microprocessor involve diverting the program flow and timing to introduce the bit flips via interrupts and embedded handlers added to the application program. In this paper, a tool based on an emulation platform using Xilinx field programmable gate arrays (FPGAs) is described, which provides an environment and methodology for the evaluation of the sensitivity of microprocessor architectures, using dynamic runtime fault injection. A case study is presented, where the robustness of MicroBlaze and Leon3 microprocessors executing a simple signal processing task written in C language is evaluated and compared. A hardened version of the program, where the key variables are protected, has also been tested, and its contributions to system robustness have also been evaluated. In addition, this paper presents a further improvement in the developed tool that allows not only the measurement of microprocessor robustness but, in addition, the study and classification of single-event upset (SEU) effects and the exact measurement of the recovery time (the time that the microprocessor takes to self repair and recover the fault-free state). The measurement of this recovery time is important for real-time critical applications, where criticality depends on both data correctness and timing. To demonstrate the proposed improvements, a new software program that implements two different software hardening techniques (one for Data and another for Control Flow) has been made, and a study of the recovery times in some significant fault-injection cases has been performed over the Leon3 processor.

Reliability Engineering & System Safety, 1988

Reliability Engineering and System Safety is an international journal devoted to the development and application of methods for the enhancement of the safety and reliability of complex technological systems, like nuclear power plants, chemical plants, hazardous waste facilities and space systems. An important aim is to achieve a balance between academic material and practical applications. The following topics are within the scope of the journal:

1989

At the system level, SEUs in processors are controlled by fault-tolerance techniques such as replication and voting, watchdog processors, and tagged data schemes [13,16,30]. SEUs in memory subsystems are controlled by use of error control codes (ECCs) [4,17,21] and a process called scrubbing. The scrubbing process periodically reads each word in the memory. If the number of faulty digits in a word is less than or equal to the number the ECC can correct, then the digits are corrected and the word is written back to memory. If the number of faulty digits exceeds the ECC's capability, the errors cannot be corrected and the memory has failed. Fault-tolerance to memory failures requires either physical redundancy via replication or temporal redundancy via checkpoint rollback schemes. In most aerospace applications physical redundancy is undesirable because mass, volume, and power are at a premium.

2007

Zdzis aw H. KLIM, Pawe SZCZEPA SKI, Marek BA AZI SKI * Bombardier Aerospace, CA, 400 chemin de la Cote-Vertu Ouest, Montréal, (Québec) H4S 1Y9, Canada, [email protected] ** Military University of Technology, Gen. S. Kaliskiego 2 St., 00-908 Warsaw 49, Poland, [email protected] *** École Polytechnique of Montréal, C.P.6079 succ. « Centre-ville », Montréal, (Québec) H3C 3A7, Canada, [email protected]

International Journal of Advance Research, Ideas and Innovations in Technology, 2019

With the development of technology, effective countermeasures of decoy launcher are developed. Decoy Launcher Defence System (DLDS) designed to detect, to track and to localize the incoming Decoy from the enemies and it is a countermeasure system. The system offers a complete solution to detect and locate an incoming Decoy and provides highly effective defence for the system. The DLDS shall enable timely defence against incoming Decoys at sufficient range from the submarine to guarantee safety and survivability of own platform. Controlling of decoy launcher plays a crucial role in launching and firing of Decoys. For controlling the Decoy Launcher, two control units are there. They are Electronic Control Unit (ECU) and Remote Unit (RU). ECU is manually controlled and it acts as a master controller for the launcher. RU is controlled by directors through remotely (infrared signals). It is necessary to improve the reliability of the control units. In order to obtain the reliability of ECU and RU of DLDS, in this paper developed the Reliability Prediction, Reliability Block Diagram (RBD) and Failure Mode Effect and Criticality Analysis (FMECA). Reliability Analysis gives the Prediction of the failure Rate and Mean Time Between Failures (MTBF). Reliability Prediction obtained in accordance with MIL-HDBK-217F2. Reliability Block Diagram (RBD) used to know the parts reliability how it contributes to success or failure of a system using logical operations of the system. FMECA used to obtain the failure modes of the components, their effect on system, identifies the criticality and corresponding changes are made in the design to reduce the failure modes. The procedure for performing a failure mode effects and criticality analysis developed by MIL-STD-1629. To control these failures proper methods are considered to improve the reliability of system. The reliability analysis is carried out using ITEMSOFT Tool.

Safety Science, 2013

Lessons from safety-critical anomalies during operation provide important information for constructing safer systems. To assist anomaly analysis, this research develops an integrated Failure Mode and Effect Analysis (FMEA) model to analyze causal scenarios and a Three-Frame Mode model to analyze the working mode inconsistencies of failure cases. The models are used to analyze 180 digital Instrumentation and Control (I&C) failure events from the operation of nuclear power plants. The results confirm software engineering principles and show that software faults and human errors are inevitable in complex systems; therefore, recovery should be emphasized and planned.

ACM Computing Surveys, 1978

This paper surveys the various problems involved in achieving very high rehability from complex computing systems, and discusses the relatmnship between system structurmg techniques and techniques of fault tolerance. Topics covered mclude: 1) protective redundancy in hardware and software; 2) the use of atomic actmns to structure the activity of a system to limit mformatmn flow; 3) error detection techniques; 4) strategies for locating and dealmg with faults and for assessing the damage they have caused; and 5) forward and backward error recovery techmques, based on the concepts of recovery line, commitment, exceptmn, and compensation. The ideas described relate to techmques used to date in systems mtended for environments in whmh high reliability is demanded Three specific systems the JPL-STAR, the Bell Laboratories ESS No. 1A processor, and the PLURIBUS are described m some detail and compared.