14,284 research outputs found
Monitoring and control in scenario-based requirements analysis
Scenarios are an effective means for eliciting, validating and documenting requirements. At the requirements level, scenarios describe sequences of interactions between the software-to-be and agents in the environment. Interactions correspond to the occurrence of an event that is controlled by one agent and monitored by another.This paper presents a technique to analyse requirements-level scenarios for unforeseen, potentially harmful, consequences. Our aim is to perform analysis early in system development, where it is highly cost-effective. The approach recognises the importance of monitoring and control issues and extends existing work on implied scenarios accordingly. These so-called input-output implied scenarios expose problematic behaviours in scenario descriptions that cannot be detected using standard implied scenarios. Validation of these implied scenarios supports requirements elaboration. We demonstrate the relevance of input-output implied scenarios using a number of examples
Formalization and Validation of Safety-Critical Requirements
The validation of requirements is a fundamental step in the development
process of safety-critical systems. In safety critical applications such as
aerospace, avionics and railways, the use of formal methods is of paramount
importance both for requirements and for design validation. Nevertheless, while
for the verification of the design, many formal techniques have been conceived
and applied, the research on formal methods for requirements validation is not
yet mature. The main obstacles are that, on the one hand, the correctness of
requirements is not formally defined; on the other hand that the formalization
and the validation of the requirements usually demands a strong involvement of
domain experts. We report on a methodology and a series of techniques that we
developed for the formalization and validation of high-level requirements for
safety-critical applications. The main ingredients are a very expressive formal
language and automatic satisfiability procedures. The language combines
first-order, temporal, and hybrid logic. The satisfiability procedures are
based on model checking and satisfiability modulo theory. We applied this
technology within an industrial project to the validation of railways
requirements
Requirements modelling and formal analysis using graph operations
The increasing complexity of enterprise systems requires a more advanced
analysis of the representation of services expected than is currently possible.
Consequently, the specification stage, which could be facilitated by formal
verification, becomes very important to the system life-cycle. This paper presents
a formal modelling approach, which may be used in order to better represent
the reality of the system and to verify the awaited or existing system’s properties,
taking into account the environmental characteristics. For that, we firstly propose
a formalization process based upon properties specification, and secondly we
use Conceptual Graphs operations to develop reasoning mechanisms of verifying
requirements statements. The graphic visualization of these reasoning enables us
to correctly capture the system specifications by making it easier to determine if
desired properties hold. It is applied to the field of Enterprise modelling
Specifying and Analysing SOC Applications with COWS
COWS is a recently defined process calculus for specifying and combining service-oriented applications, while modelling their dynamic behaviour. Since its introduction, a number of methods and tools have been devised to analyse COWS specifications, like e.g. a type system to check confidentiality properties, a logic and a model checker to express and check functional properties of services. In this paper, by means of a case study in the area of automotive systems, we demonstrate that COWS, with some mild linguistic additions, can model all the phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, orchestration, deployment, reconfiguration and execution. We also provide a flavour of the properties that can be analysed by using the tools mentioned above
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