It is customary to assess the reliability of underground oil and gas pipelines in the presence of excessive loading and corrosion effects to ensure a leak-free transport of hazardous materials. The main idea behind this reliability analysis is to model the given pipeline system as a Reliability Block Diagram (RBD) of segments such that the reliability of an individual pipeline segment can be re...

A trend actually characterizing any technological and application field is the use of control and computing devices. This moves the attention of the insiders on the management of more complex processes and systems, modifying requirements, tasks and skills. In this scenario the dependability evaluation becomes strategic. The increasing complexity of systems requires a serious revision of the tec...

In a phased mission the relevant system configuration (block diagram or fault tree) changes during consecutive time periods (phases). Many systems are required to perform phased missions. A classic example is a space vehicle. A reliability analysis for a phased mission encounters complexities not present with just one phase, but can be transformed into an analysis of a synthetic single phase ca...

Combinatorial models for reliability analysis (like fault-trees or block diagram) are static models that cannot include any type of component dependence. In the CTMC (Continuous Time Markov Chain) framework, the transition rates can depend on the state of the system thus allowing the analyst to include some dependencies among components. However, in more general terms, the system reliability ma...

This paper discusses a discrete event simulation model for the availability analysis of weapon systems. This model incorporates missions, operational tasks and system reliability structures to analyze the availability of a weapon system. The proposed simulation model consists of 5 modules: Simulation Engine, Maintenance Organizations, System, its Mission Profile and RBD which are based on missi...

In the present paper, a complete process from reliability evaluation to design modification is proposed and also applied to a newly designed and manufactured Remotely Piloted Helicopter (RPH) by the authors. First of all, a description of all platform subsystems is presented. After that, function diagram and also product tree of the whole system is depicted for further analysis. Then, the relia...

Reliability Block Diagrams (RBDs) allow us to model the failure relationships of complex systems and their sub-components and are extensively used for system reliability, availability, dependability and maintainability analyses of many engineering systems. Traditionally, Reliability Block Diagrams (RBD) are analyzed using paper-and-pencil proofs or computer simulations. Recently, formal techniq...

Each system has its own definition of reliability. Reliability in mobile ad-hoc networks (MANET) could be interpreted as, the probability of reaching a message from a source node to destination, successfully. The variability and volatility of the MANET configuration makes typical reliability methods (e.g. reliability block diagram) inappropriate. It is because, no single structure or configurat...

Fault Tree (FT) is a standard failure modeling technique that has been extensively used to predict reliability, availability and safety of many complex engineering systems. In order to facilitate the formal analysis of FT based analyses, a higher-order-logic formalization of FTs has been recently proposed. However, this formalization is quite limited in terms of handling large systems and trans...

The quality of Vessel Traffic Management and Information Systems depends on the quality of all subsystems, in particular the quality of control centres. The most commonly used quantitative indicators of the control centres’ quality are: reliability, availability, safety, and system failure. Therefore, a block diagram of reliability and the model for reliability / availability (Markov model) hav...