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Today most maintenance optimization models are established and interpreted within the classical statistical framework. There exist true failure time distributions and cost functions which we have to estimate. Using this approach, the results from the analysis are to a large extent disturbed by a discussion of uncertainty of the estimates. In this note we draw attention to an alternative approach: the fully Bayesian approach with focus on observable quantities and using subjective probabilities. We argue that this latter approach is more suitable as a tool for making decisions. The subjectivistic approach provides the framework of coherent use of (expert) judgment, which constitutes a significant (sometimes the only) part of information that is available to us.

This study aims to argue that in the case of quantitative security risk assessment, individuals do not estimate probabilities as a likelihood measure of event occurrence.

The study uses the most commonly used quantitative assessment approach, the annualized loss expectancy (ALE), to support the three research hypotheses.

The estimated probabilities used in quantitative models are subjective.

The ALE model used in security risk assessment, although it is presented in the literature as quantitative, is, in fact, qualitative being influenced by bias.

The study provides a factual basis showing that quantitative assessment is neither realistic nor practical to the real world.

A model that cannot be tested experimentally is not a scientific model. In fact, the probability used in ISRM is an empirical probability or estimator of a probability because it estimates probabilities from experience and observation.

Since the mid-1990s, enterprise risk management (ERM) has proliferated in both the private and public sector as a holistic, enterprise-wide approach to risk management. In this chapter, we begin by exploring the economic, regulatory and professional context of ERM practices in Norway. To gain an understanding of the current state of ERM practices among Norwegian entities, we have conducted a survey among members of the Institute of Internal Auditors (IIA) Norway. Based on the survey data, we go on to analyse the perceived maturity of risk management practices of the surveyed organizations, as well as their integration of risk management with governance mechanisms and accounting practices. Four main findings emerged from the survey. We firstly observed that a majority of the respondents perceived that they had implemented ERM. Secondly, the average maturity of risk management practice is at a medium level, with ambitions to improve it further in the future. We further observed that a majority of the organizations have established risk management governance structures regarding the roles of risk management. However, there is still work to be done in relation to risk management functions in order for them to gain more attention and influence in the organizations. Finally, we find that risk management is more integrated with reporting processes than with strategic and performance planning processes, suggesting a more reactive than proactive approach to managing risks.

The purpose of this paper is to describe an application of an effective risk-based methodology to support a living maintenance programme for railway infrastructure.

The overall research strategy is a single case study of switches and crossings at the Iron Ore Line in northern Sweden. The analysis was performed as a risk workshop guided by a methodology that integrates reliability-centred maintenance and barrier analysis.

The applied methodology is valuable to systematise and improve the existing maintenance programme, as well as supporting a continued living maintenance programme.

The single case study approach may decrease the validity of the achieved results. However, similar case studies corroborate the results, which affect the validity in a positive way.

The resulting maintenance programme is effective, through compliance with external requirements, and more efficient, through improvements of tasks and intervals.

An enhanced railway infrastructure maintenance programme contributes to improved safety, punctuality, and costs. Hence, railway becomes a more attractive mode of transport. Thereby, it also supports a safety performance of the railway that society is willing to pay for.

Significant improvements of the maintenance programme are achieved through adjustment of inspection intervals and tasks. The results also support the development of indicators, monitoring, and continuous improvement.

The purpose of this paper is to provide an overview of RAMS engineering in industry and research.

A range of research articles (1988‐2005) covering RAMS engineering is discussed to provide a practical and theoretical overview of RAMS engineering in industry and research.

The paper provides information about the current scenario and also about the past scenario of RAMS engineering in research and industry. Research limitations/implications – This paper reviews much of the literature on RAMS engineering. The literature is collected from major journals and conference proceedings, the period covered is from 1988 to 2005. The authors have tried to make it reasonably comprehensive, but those papers which are not included were either inadvertently overlooked or considered peripheral to this survey. In the present work the authors have only considered those articles which have included two or more aspects of RAMS. Practical implications – The paper is a very useful source of information for researchers working in the area of RAMS engineering. Originality/value – This paper offers help to researchers in understanding the current and past status of RAMS.