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The aim of this study is to demonstrate that hybrid redundancy systems are superior to the conventional N‐modular redundancy (NMR) systems.

The hybrid redundancy system is a synthesis of the NMR system and the standby redundancy. Each module of the NMR has access to k cold spares (k<N) and a repair facility. A semi‐Markov model for the hybrid redundancy system is developed and transient analysis is performed.

Some dependability measures such as availability, reliability, mean time to failure and steady‐state availability are obtained.

This paper presents the transient analysis of the hybrid redundancy systems. The results obtained will be useful to reliability engineers and reliability practitioners.

Discusses the long existing and confusing problems of establishing the relationship of who is, and who if not, a dependent worker. Reflects developments which have occurred in British law as it affects the employment field, plus an evaluation and analysis of some of the different types of employment relationships which have evolved by examining, where possible, the status of each of these relationships. Concludes that the typical worker nowadays finds himself in a vulnerable position both economically and psychologically owing to the insecurity which exists.

The purpose of this paper is to present the case for an analysis of communication at the supra-individual level as a means of rendering the understanding of learning and acting tractable. The paper introduces a method of analysis of redundancy to achieve this.

The paper argues for a supra-individual approach to acting, learning, and understanding against focusing on an individual or quasi-transcendental “observer”. The argument is outlined in four steps: first, articulation of the dynamics of the communication system; second, consideration of the redundancies of expectations within communication; third, the computation of anticipation which enables the authors to model meaning processing; and fourth the feedback of meaning processing on information processing can be measured as redundancy. Anticipated future states can reflexively drive reconstructions in meaning-processing systems.

The social system can be considered as a symbolic order of coordination mechanisms. Reflexive agency can access this order and partake in it. However, expectations and their structures do not “exist”, but remain uncertain with the status of hypotheses. Historical embodiment in intentional action is structurally coupled to the order of expectations. The historical instantiations condition and enable the further development of the expectations as a retention mechanism.

The modelling and measurement of meaning processing in terms of inversion of the arrow of time and the generation of redundancy provide extensions to the mathematical theory of communication.

There are three main themes which run through this article. They are: (1) To examine the role which personnel management may play in a redundancy situation; (2) To ask if redundancy as a process can be justifiably conceived in psychological terms and investigated as such, and (3) To consider how the different stages of this process may be handled, from a social psychological point of view, and, further, what the effects of this may be on the remaining work force.

The purpose of this paper is to optimize system redundancy and maintenance intervals of a propane pre-cooled mixed refrigerant (C3MR) liquefaction process on floating liquefied natural gas (FLNG) export platforms.

The reliability modeling is based on the time-dependent Markov approach. Four different system options are studied, with various degree of redundancy. Failures in the liquefaction system usually lead to shutdown the whole LNG production plant. The associated shutdown cost is compared with the cost of introducing redundancy and the cost of onboard maintenance. To ensure a high profitability, a model for maintenance optimization is utilized and applied to the main unit of the C3MR liquefaction system to minimize the onboard maintenance cost.

The results indicated that the introduction of a second liquefaction system (as a standby unit) is the best option for liquefaction plant in terms of reliability and cost. This will substantially reduce the unavailability from 14.7 to 2.19 percent of the total operational hours. Based on the presented system configuration, the annual system profit will increase by 180 million USD if the redundancy is implemented on FLNG export ships. The optimum maintenance intervals of major process components are also calculated to minimize the total cost of maintenance.

The originality of this paper lies within the context in investigating the reliability of the C3MR liquefaction system on LNG floating export terminals using Markov modeling for the first time.

Examines the trade‐off between system redundancy and acceptance sampling as alternative means to improve system reliability. We assume that components of the system follow an exponential failure law and investigate expected times to failure of systems of various levels of component redundancy which have been exposed to acceptance sampling plans of various levels of stringency. We also show the probability distributions of system reliability for outgoing lots at various levels of component redundancy and sampling stringency. The paper shows a straightforward method for calculating these trade‐offs and provides the decision maker with a previously unavailable tool of system design and testing.

The librarian and researcher have to be able to uncover specific articles in their areas of interest. This Bibliography is designed to help. Volume IV, like Volume III, contains features to help the reader to retrieve relevant literature from MCB University Press' considerable output. Each entry within has been indexed according to author(s) and the Fifth Edition of the SCIMP/SCAMP Thesaurus. The latter thus provides a full subject index to facilitate rapid retrieval. Each article or book is assigned its own unique number and this is used in both the subject and author index. This Volume indexes 29 journals indicating the depth, coverage and expansion of MCB's portfolio.

As a response to the growing operational and disruptive threats to water distribution networks (WDNs), researchers have developed a vast array of methods for the reliability analysis of WDNs. In order to follow this growing number of methods, this paper reviews and documents in one place the historical developments in the reliability analysis of WDN.

A systematic literature review (SLR) is carried out to summarize the state-of-the-art research on reliability analysis of WDNs. In conducting this systemic literature review, the authors adopted an iterative approach to define appropriate keywords, analyze and synthesize data and finalizing the classification results.

First, the hydraulic approach to reliability analysis is currently pervasive, and relatively little academic research has addressed the topological reliability analysis of WDNs. Second, in order to provide a comprehensive picture of the network reliability, a different approach that integrates topological and hydraulic attributes seems a more effective method. Third, the conventional reliability analysis methods are only effective for demonstrating a snapshot of these networks at a given point in time. The availability of methods that enable researchers to evaluate the reliability in response to changes in its variables is still a major challenge.

The present paper facilitates future research in the reliability analysis of WDNs by providing a source of references for researchers and water utilities. Further, this article makes a contribution to the literature by offering a roadmap for future reliability analysis of WDNs by reviewing the evolution of the current reliability analysis methods throughout history.