Preface

System reliability has its importance in engineering, to identify the least reliable components in the system in order to improve the design. In the complex system, this becomes a difficult task. In this domain, the analysts need a mathematical approach to identify and to quantify the importance of each component in the system. For keeping a system in working conditions, activities of maintenance must be involved.

Researchers from the entire world write to figure out their newest results and to contribute new ideas or ways in the field of system reliability. They were inventive and see the field as inspiration for research. The kinds of applications they treat are indicative of each author's interest and engagement. The book shows the degree of information from authors in the field and their dedication, appreciation and enthusiasm of the field they care about.

The authors choose to publish their research project results to explain reliability patterns in different applications, to explain variations of parameter in different industrial processes and to test the consequences of parameter variations on processes; they conducted experimental tests of hypothesis, developed mathematical versions of reliability models and used funda‐ mental ideas to address applied problems in novel ways.

The authors were motivated to write the chapters to keep them focused, energized and in‐ spired, using the great opportunity for publishing in an open access way through a wellknown publishing house. The preface must be seen as a good thought of wisdom about their hopes and their motivation and achieving their goals.

In a brief description, the book has four sections: reliability, reliability of electronic devices, power system reliability and feasibility and maintenance.

The book can become a valuable tool for professors, students and professionals, with its pre‐ sentation of some issues that may be taken as examples applicable to new practical situations. Based on the authors' experience, the book may be popular among specialists.

The book presents cases that illustrate the application in a variety of domains. The first section begins with an interesting system reliability analysis based on goal-oriented methodology, fol‐ lowed by some applications as reliability design of water-dispensing systems, based on field data and parametric accelerated life tests; reliability evaluation of drivetrains for off-highway machines, taken into consideration the load cycles and components load, with examples of ap‐ plication of the power shift transmission and the offshore winch; a predictive analysis on equipment downtime in the oil and gas industry to improve maintenance and to prevent haz‐ ardous event that could harm people and the environment; a study for extending the useful life of asset, based on an adaptive maintenance methodology that uses the reliability-centred maintenance approach to define a degradation-based adaptive maintenance model; a study in the area of network reliability analysis to speed up obtaining of the cumulative bounds for

faster feasibility decision; analysis of standard reliability parameters of technical systems' parts based on spare parts forecasting using Rayleigh and Weibull's models; and a study on cannibalisation for improving system reliability, with reduced adverse effects on maintenance costs and personnel morale. The second section begins with an interesting mathematical study on the multiple temperature operational life testing procedure, for electronic industry, to re‐ place the standard high-temperature operational life, by predicting the system failure rate by testing a small number of components, calculating the mean time to failure. Some applications follow: reliability prediction of smart maximum PowerPoint converter in photovoltaic applica‐ tions; the reliability of die interconnections used in plastic discrete power packages, dedicated to on-board electronic systems used in applications such as automotive industry; and the anal‐ ysis of the effects of mechanical and electrical straining on performances of conventional thickfilm resistors, from micro- and macro-structural, charge transport and low-frequency noise aspects. The third section presents the following: analysis of software and hardware develop‐ ment in phasor measurement unit technology to ensure the secure operation and stability of transmission systems in the electric power system; a study on electric interruptions and loss of supply in power systems, based on interruption modelling using Weibull-Markov process with degradation; a short overview of electricity distribution networks with its protection de‐ vices for assessment of protection and reliability; and a technical-economic feasibility study of autonomous hybrid AC/DC microgrid system. The fourth section presents a predictive model‐ ling of emergency services in electric power distribution systems for resource planning during extreme weather events when considering the geographic dispersion of such services and also the time windows that comprise the amount of service time demanded; a web-based decisionsupport system aimed to aid distribution system operators for planning and executing cus‐ tomer and maintenance services in the electric power distribution system; a short review of some maintenance models, with examples of imperfect maintenance models in literature, to identify suitable models for real cases; and a mathematical model–based study of preventive maintenance of a repairable equipment whose lifetime distribution depends on the operating environment severity.

The editor thanks the authors for their excellent contributions in the field and understanding during the process of editing. Also, the editor thanks to all the editorial personnel involved in this book publication. The publishing provided a set of editorial standards, which ensured the quality of the scientific level of relevance of accepted chapters.

> **Prof. Constantin Volosencu** Politehnica University of Timișoara Timisoara, Jud. Timis, Romania

**Reliability**

**Section 1**

**Section 1**
