41,584 research outputs found
Formal Verification of Real-Time Function Blocks Using PVS
A critical step towards certifying safety-critical systems is to check their
conformance to hard real-time requirements. A promising way to achieve this is
by building the systems from pre-verified components and verifying their
correctness in a compositional manner. We previously reported a formal approach
to verifying function blocks (FBs) using tabular expressions and the PVS proof
assistant. By applying our approach to the IEC 61131-3 standard of Programmable
Logic Controllers (PLCs), we constructed a repository of precise specification
and reusable (proven) theorems of feasibility and correctness for FBs. However,
we previously did not apply our approach to verify FBs against timing
requirements, since IEC 61131-3 does not define composite FBs built from
timers. In this paper, based on our experience in the nuclear domain, we
conduct two realistic case studies, consisting of the software requirements and
the proposed FB implementations for two subsystems of an industrial control
system. The implementations are built from IEC 61131-3 FBs, including the
on-delay timer. We find issues during the verification process and suggest
solutions.Comment: In Proceedings ESSS 2015, arXiv:1506.0325
Multilevel Contracts for Trusted Components
This article contributes to the design and the verification of trusted
components and services. The contracts are declined at several levels to cover
then different facets, such as component consistency, compatibility or
correctness. The article introduces multilevel contracts and a
design+verification process for handling and analysing these contracts in
component models. The approach is implemented with the COSTO platform that
supports the Kmelia component model. A case study illustrates the overall
approach.Comment: In Proceedings WCSI 2010, arXiv:1010.233
Research Findings on Empirical Evaluation of Requirements Specifications Approaches
Numerous software requirements specification (SRS) approaches have been proposed in software engineering. However, there has been little empirical evaluation of the use of these approaches in specific contexts. This paper describes the results of a mapping study, a key instrument of the evidence-based paradigm, in an effort to understand what aspects of SRS are evaluated, in which context, and by using which research method. On the basis of 46 identified and categorized primary studies, we found that understandability is the most commonly evaluated aspect of SRS, experiments are the most commonly used research method, and the academic environment is where most empirical evaluation takes place
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Arguing satisfaction of security requirements
This chapter presents a process for security requirements elicitation and analysis,
based around the construction of a satisfaction argument for the security of a
system. The process starts with the enumeration of security goals based on assets
in the system, then uses these goals to derive security requirements in the form of
constraints. Next, a satisfaction argument for the system is constructed, using a
problem-centered representation, a formal proof to analyze properties that can be
demonstrated, and structured informal argumentation of the assumptions exposed
during construction of the argument. Constructing the satisfaction argument can
expose missing and inconsistent assumptions about system context and behavior
that effect security, and a completed argument provides assurances that a system
can respect its security requirements
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Using formal methods to support testing
Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent
years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing
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