Reliability Analysis Model

RAM program determines probability of success for one or more given objectives in any complex system. Program includes failure mode and effects, criticality and reliability analyses, and some aspects of operations, safety, flight technology, systems design engineering, and configuration analyses

Probabilistic Modelling in Solving Analytical Problems of System Engineering

This chapter provides some aspects to probabilistic modelling in solving analytical problems of system engineering. The historically developed system of the formation of scientific bases of engineering calculations of characteristics of strength, stability, durability, reliability, survivability and safety is considered. The features of deterministic and probabilistic problems of evaluation of the characteristics of strength, stiffness, steadiness, durability and survivability are considered. Probabilistic problems of reliability, security, safety and risk assessment of engineering systems are formulated. Theoretical bases and methods of probabilistic modelling of engineering systems are stated. The main directions of solving the problems of ensuring security and safety according to the accident risk criteria are determined. The possibilities of probabilistic modelling methods in solving the problems of strength, reliability and safety of engineering systems are shown in practical examples

Formal transformation methods for automated fault tree generation from UML diagrams

With a growing complexity in safety critical systems, engaging Systems Engineering with System Safety Engineering as early as possible in the system life cycle becomes ever more important to ensure system safety during system development. Assessing the safety and reliability of system architectural design at the early stage of the system life cycle can bring value to system design by identifying safety issues earlier and maintaining safety traceability throughout the design phase. However, this is not a trivial task and can require upfront investment. Automated transformation from system architecture models to system safety and reliability models offers a potential solution. However, existing methods lack of formal basis. This can potentially lead to unreliable results. Without a formal basis, Fault Tree Analysis of a system, for example, even if performed concurrently with system design may not ensure all safety critical aspects of the design. [Continues.]</div

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

Photovoltaic power system reliability considerations

An example of how modern engineering and safety techniques can be used to assure the reliable and safe operation of photovoltaic power systems is presented. This particular application is for a solar cell power system demonstration project designed to provide electric power requirements for remote villages. The techniques utilized involve a definition of the power system natural and operating environment, use of design criteria and analysis techniques, an awareness of potential problems via the inherent reliability and FMEA methods, and use of fail-safe and planned spare parts engineering philosophy

Failure Mode and Effect Analysis a Tool for Reliability Evaluation: Review

The purpose of safety designing is generally not on cost, but rather on saving life and nature, and consequently bargains just with specific risky system failure modes. High reliability levels are the consequence of good designing, scrupulousness and dependably never the aftereffect of re-dynamic failure management. Failure mode and effect analysis (FMEA) is a helpful technique analyzing engineering system reliability. The study focused on the use of FMEA technique to analyze the reliability of engineering equipment or components in selected areas such as: Wind Turbine component, Manufacturing Industries, Medical field and in evaluating the performances of Robots in different fields. The study showed the importance of FMEA as used widely in analyzing engineering equipment with regards to reliability

Reliability and Maintainability Engineering - A Major Driver for Safety and Affordability

The United States National Aeronautics and Space Administration (NASA) is in the midst of an effort to design and build a safe and affordable heavy lift vehicle to go to the moon and beyond. To achieve that, NASA is seeking more innovative and efficient approaches to reduce cost while maintaining an acceptable level of safety and mission success. One area that has the potential to contribute significantly to achieving NASA safety and affordability goals is Reliability and Maintainability (R&M) engineering. Inadequate reliability or failure of critical safety items may directly jeopardize the safety of the user(s) and result in a loss of life. Inadequate reliability of equipment may directly jeopardize mission success. Systems designed to be more reliable (fewer failures) and maintainable (fewer resources needed) can lower the total life cycle cost. The Department of Defense (DOD) and industry experience has shown that optimized and adequate levels of R&M are critical for achieving a high level of safety and mission success, and low sustainment cost. Also, lessons learned from the Space Shuttle program clearly demonstrated the importance of R&M engineering in designing and operating safe and affordable launch systems. The Challenger and Columbia accidents are examples of the severe impact of design unreliability and process induced failures on system safety and mission success. These accidents demonstrated the criticality of reliability engineering in understanding component failure mechanisms and integrated system failures across the system elements interfaces. Experience from the shuttle program also shows that insufficient Reliability, Maintainability, and Supportability (RMS) engineering analyses upfront in the design phase can significantly increase the sustainment cost and, thereby, the total life cycle cost. Emphasis on RMS during the design phase is critical for identifying the design features and characteristics needed for time efficient processing, improved operational availability, and optimized maintenance and logistic support infrastructure. This paper discusses the role of R&M in a program acquisition phase and the potential impact of R&M on safety, mission success, operational availability, and affordability. This includes discussion of the R&M elements that need to be addressed and the R&M analyses that need to be performed in order to support a safe and affordable system design. The paper also provides some lessons learned from the Space Shuttle program on the impact of R&M on safety and affordability

Evolution of maintenance strategies in oil and gas industries: the present achievements and future trends

Engineering Systems maintenance and reliability challenges have drawn serious attention of researchers and industrialists all over the world due to continuous evolution, innovation and complexity of modern technologies deployed in manufacturing and production systems. These systems need very high reliability and availability due to business, mission and safety critical nature of their operations. This paper reviews evolution of systems or equipment maintenance strategies practiced over the years in complex industrial and manufacturing systems such as oil and gas production systems, satellite communication system, spacecraft navigational system, nuclear power plants, etc. The paper also examines the current maintenance and reliability philosophies, their limitations and highlights major breakthroughs and achievements with regards to complex engineering systems maintenance. Intelligent maintenance, a novel approach to complex engineering systems maintenance and reliability sustainment is proposed. The proposed approach reintegrates operation and maintenance phase into system development life cycle, adopts advanced engineering tools and methodology in developing condition-based predictive maintenance, an intelligent maintenance system with resilient, autonomous and adaptive capabilities. Application of Neural network approach to multisensor data fusion for condition-based predictive maintenance system is briefly presented

Reliability Research of Power Distribution System For Important Units at the Airfield

Important power units at the airport are the direct units of aviation security, the reliability of power supply and distribution system directly affect the safety of it for aviation security. This paper analyzes the important units of electricity power supply system into the units of reliability. The basic reliability model and the mission reliability model are constructed respectively and the corresponding reliabilities are calculated. Then the paper studies on the relationship between two kinds of reliability as well as the influence on the reliability of power supply and distribution system, providing theoretical basis of planning, equipment selection, engineering design, reliable operation and maintenance management for important units of power supply system

Letters to the Editor

Software Safety vs Software Reliability While looking back through Vol. 56, No. 1 (Summer 2020) of Journal of System Safety, I finally took the time to read Nathaniel Ozarin’s article “Lessons Learned in a Complex Software Safety Program.” The article is quite interesting and thought provoking, comparing what actually occurs while implementing a system safety program to the idealized descriptions found in documents such as MIL-STD-882, JSSSEH and AOP-52. While I found the article interesting and informative, I noted that the author consistently characterizes the “software safety problem” as a “reliability” problem, focused on finding and preventing “failures” and ensuring high “reliability.” Some Thoughts on the Probabilistic Criteria for Ensuring Safe Airplane-System Designs We have been employed in the risk sciences for a total of 86 years, including 62 years in reliability engineering and safety engineering positions at The Boeing Company. For many of those years, Yellman was the designated “Risk-Analysis Focal” (person) for Boeing’s 707, 727, 737 and 757 airplane models. For several decades, the United States government has published the same criteria, created by the U.S. Federal Aviation Administration (FAA), intended to ensure that the systems on large (transport-category) aircraft have been designed to be safe [Refs. 1 and 2]. But we believe that the criteria have failed to prevent certain aircraft accidents, and we think that the reasons for that should be better understood. We hope that this discussion will contribute to a better understanding by examining the part potentially played in those accidents by the FAA’s criteria that are defined probabilistically