Expert Elicitation for Reliable System Design

This paper reviews the role of expert judgement to support reliability assessments within the systems engineering design process. Generic design processes are described to give the context and a discussion is given about the nature of the reliability assessments required in the different systems engineering phases. It is argued that, as far as meeting reliability requirements is concerned, the whole design process is more akin to a statistical control process than to a straightforward statistical problem of assessing an unknown distribution. This leads to features of the expert judgement problem in the design context which are substantially different from those seen, for example, in risk assessment. In particular, the role of experts in problem structuring and in developing failure mitigation options is much more prominent, and there is a need to take into account the reliability potential for future mitigation measures downstream in the system life cycle. An overview is given of the stakeholders typically involved in large scale systems engineering design projects, and this is used to argue the need for methods that expose potential judgemental biases in order to generate analyses that can be said to provide rational consensus about uncertainties. Finally, a number of key points are developed with the aim of moving toward a framework that provides a holistic method for tracking reliability assessment through the design process.Comment: This paper commented in: [arXiv:0708.0285], [arXiv:0708.0287], [arXiv:0708.0288]. Rejoinder in [arXiv:0708.0293]. Published at http://dx.doi.org/10.1214/088342306000000510 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

EEMCS final report for the causal modeling for air transport safety (CATS) project

This document reports on the work realized by the DIAM in relation to the completion of the CATS model as presented in Figure 1.6 and tries to explain some of the steps taken for its completion. The project spans over a period of time of three years. Intermediate reports have been presented throughout the project’s progress. These are presented in Appendix 1. In this report the continuous‐discrete distribution‐free BBNs are briefly discussed. The human reliability models developed for dealing with dependence in the model variables are described and the software application UniNet is presente

How do software architects consider non-functional requirements: an exploratory study

© 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Dealing with non-functional requirements (NFRs) has posed a challenge onto software engineers for many years. Over the years, many methods and techniques have been proposed to improve their elicitation, documentation, and validation. Knowing more about the state of the practice on these topics may benefit both practitioners' and researchers' daily work. A few empirical studies have been conducted in the past, but none under the perspective of software architects, in spite of the great influence that NFRs have on daily architects' practices. This paper presents some of the findings of an empirical study based on 13 interviews with software architects. It addresses questions such as: who decides the NFRs, what types of NFRs matter to architects, how are NFRs documented, and how are NFRs validated. The results are contextualized with existing previous work.Peer ReviewedPostprint (author’s final draft

Universal quantification in the nominal domain in American Sign Language

While quantification in American Sign Language (ASL) has been an object of linguistic investigation for more than two decades, there are still relatively few studies on that topic. Most crucially, detailed descriptions of many aspects of quantification in ASL are still lacking. This dissertation is a description of universal quantification in the nominal domain in ASL. Using data I collected from eight deaf native ASL signers, I report various lexical, morphological, and syntactic strategies that signers use to encode universal quantification. These strategies include explicit marking of quantification by means of lexical universal quantifiers and aspectual marking on directional verbs. In addition, I describe universal interpretations in sentences with definite plural and mass noun phrases and in sentences with predicates conveying total affectedness of the patient/theme argument. Focusing further on ASL lexical quantifiers, I provide a detailed description that addresses variation in forms, morphological properties, and syntax. This description is further supplemented by the discussion of possible historical sources of ASL universal quantifiers and the place of non-native quantificational expressions in the lexicon. From a typological perspective, I discuss modality-independent and modality-specific properties that explain the distribution of universal quantifiers in ASL. In particular, I consider distributivity, interaction with the semantics of nouns, and the role of space.Linguistic