A methodology for the requirements analysis of critical real-time systems

PhD ThesisThis thesis describes a methodology for the requirements analysis of critical real-time systems. The methodology is based on formal methods, and provides a systematic way in which requirements can be analysed and specifications produced. The proposed methodology consists of a framework with distinct phases of analysis, a set oftechniques appropriate for the issues to be analysed at each phase of the framework, a hierarchical structure of the specifications obtained from the process of analysis, and techniques to perform quality assessment of the specifications. The phases of the framework, which are abstraction levels for the analysis of the requirements, follow directly from a general structure adopted for critical real-time systems. The intention is to define abstraction levels, or domains, in which the analysis of requirements can be performed in terms of specific properties of the system, thus reducing the inherent complexity of the analysis. Depending on the issues to be analysed in each domain, the choice of the appropriate formalism is determined by the set of features, related to that domain, that a formalism should possess. In this work, instead of proposing new formalisms we concentrate on identifying and enumerating those features that a formalism should have. The specifications produced at each phase of the framework are organised by means of a specification hierarchy, which facilitates our assessment of the quality of the requirements specifications, and their traceability. Such an assessment should be performed by qualitative and quantitative means in order to obtain high confidence (assurance) that the level of safety is acceptable. In order to exemplify the proposed methodology for the requirements analysis of critical real-time systems we discuss a case study based on a crossing of two rail tracks (in a model railway), which raises safety issues that are similar to those found at a traditional level crossing (i.e. rail-road)CAPES/Ministry of Education (Brazil

Academic Panel: Can Self-Managed Systems be trusted?

Trust can be defined as to have confidence or faith in; a form of reliance or certainty based on past experience; to allow without fear; believe; hope: expect and wish; and extend credit to. The issue of trust in computing has always been a hot topic, especially notable with the proliferation of services over the Internet, which has brought the issue of trust and security right into the ordinary home. Autonomic computing brings its own complexity to this. With systems that self-manage, the internal decision making process is less transparent and the ‘intelligence’ possibly evolving and becoming less tractable. Such systems may be used from anything from environment monitoring to looking after Granny in the home and thus the issue of trust is imperative. To this end, we have organised this panel to examine some of the key aspects of trust. The first section discusses the issues of self-management when applied across organizational boundaries. The second section explores predictability in self-managed systems. The third part examines how trust is manifest in electronic service communities. The final discussion demonstrates how trust can be integrated into an autonomic system as the core intelligence with which to base adaptivity choices upon

Robustness-Driven Resilience Evaluation of Self-Adaptive Software Systems

An increasingly important requirement for certain classes of software-intensive systems is the ability to self-adapt their structure and behavior at run-time when reacting to changes that may occur to the system, its environment, or its goals. A major challenge related to self-adaptive software systems is the ability to provide assurances of their resilience when facing changes. Since in these systems, the components that act as controllers of a target system incorporate highly complex software, there is the need to analyze the impact that controller failures might have on the services delivered by the system. In this paper, we present a novel approach for evaluating the resilience of self-adaptive software systems by applying robustness testing techniques to the controller to uncover failures that can affect system resilience. The approach for evaluating resilience, which is based on probabilistic model checking, quantifies the probability of satisfaction of system properties when the target system is subject to controller failures. The feasibility of the proposed approach is evaluated in the context of an industrial middleware system used to monitor and manage highly populated networks of devices, which was implemented using the Rainbow framework for architecture-based self-adaptation

10431 Abstracts Collection -- Software Engineering for Self-Adaptive Systems

From 24.10. to 29.10.2010, the Dagstuhl Seminar 10431 ``Software Engineering for Self-Adaptive Systems\u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Self-adaptive Artificial Intelligence

Machine learning tools, like deep neural networks, are perceived to be black boxes. That is, the only way of changing their internal data models is to retrain these models using different inputs. This is ineffective in dynamic systems that are prone to changes, like concept drift. A new promising solution is transparent artificial intelligence, based on the notions of interpretation and explanation, whose objective is to correlate the internal data models with predictions. The research question being addressed is whether we can have a self-adaptive machine learning system that is able to interpret and explain its data model in order for it to be controlled. In this position paper, we present our initial thoughts whether this can be achieved

Microservices Architectures and Technical Debt: A Self-adaptation View

In this paper, we discuss the impact that technical debt (TD) may have on MSA regarding some quality attributes, like security, and hypothesise how self-adaptation could be useful in dealing with some aspects of TD

Evaluating Self-Adaptive Authorisation Infrastructures through Gamification

Self-adaptive systems are able to modify their behaviour and/or structure in response to changes that occur to the system itself, its environment, or even its goals. In terms of authorisation infrastructures, self-adaptation has been shown to provide runtime capabilities for specifying and enforcing access control policies and subject access privileges, with a goal to mitigate insider threat. The evaluation of self-adaptive authorisation infrastructures, particularly, in the context of insider threats, is challenging because simulation of malicious behaviour can only demonstrate a fraction of the types of abuse that is representative of the real-world. In this paper, we present an innovative approach based on an ethical game of hacking, protected by an authorisation infrastructure. A key feature of the approach is the ability to observe user activity pre- and post-adaptation when evaluating runtime consequences of self- adaptation. Our live experiments captured a wide range of unpredictable changes, including malicious behaviour related to the exploitation of known vulnerabilities. As an outcome, we demonstrated the ability of our self-adaptive authorisation infrastructure to handle malicious behaviour given the existence of real and intelligent users, in addition to capturing how users responded to adaptation

08031 Abstracts Collection -- Software Engineering for Self-Adaptive Systems

From 13.01. to 18.01.2008, the Dagstuhl Seminar 08031 ``Software Engineering for Self-Adaptive Systems\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available