Ricardo J. Rodríguez

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The adequate system performance is usually a critical requirement to be checked during the verification phase of a system. Thus, accurately measuring the performance of current industrial systems, which are often modelled as a Discrete Event Systems (DES), is a need. Due to the state explosion problem, the performance evaluation of DES becomes increasingly(More)
—Many discrete systems with shared resources from different artificial domains (such as manufacturing, logistics or web services) can be modelled in terms of timed Petri nets. Two studies that may result of interest when dealing with such a systems are the performance evaluation (or completed jobs per unit of time) and the resource optimisation. Exact(More)
Critical infrastructures, usually designed to handle disruptions caused by human errors or random acts of nature, define assets whose normal operation must be guaranteed to maintain its essential services for human daily living. Malicious intended attacks to these targets need to be considered during system design. To face with these situations, defense(More)
Security attacks aim to system vulnerabilities that may lead to operational failures. In order to react to attacks software designers use to introduce Fault-Tolerant Techniques (FTTs), such as recovery procedures, and/or Security Mechanisms (SMs), such as encryption of data. FTTs and SMs inevitably consume system resources, hence they influence the system(More)
Safety becomes a primordial assessment in safety-related systems where human lives can be somehow put in risk, needing to comply with safety requirements defined by industry standards such as IEC 61508, ISO 26262 or DO-178C. Safety contracts are useful to specify these requirements (as assumptions and guarantees), thus assuring an expected level of(More)
Software designs equipped with specification of dependability techniques can help engineers to develop critical systems. In this work, we start to envision how a software engineer can assess that a given dependability technique is adequate for a given software design, i.e., if the technique, when applied, will cause the system to meet a dependability(More)
—Many artificial systems can be modeled as discrete dynamic systems in which resources are shared among different tasks. The performance of such systems, which is usually a system requirement, heavily relies on the number and distribution of such resources. The goal of this paper is twofold: first, to design a technique to estimate the steady-state(More)
Validation of a system design enables to discover specification errors before it is implemented (or tested), thus hopefully reducing the development cost and time. The Unified Modelling Language (UML) is becoming widely accepted for the early specification and analysis of requirements for safety-critical systems, although a better balance between UML's(More)
The verification of safety becomes crucial in critical systems where human lives depend on the correct functioning of such systems. Formal methods have often been advocated as necessary to ensure the reliability of software systems, albeit with a considerable effort. In any case, such an effort is cost-effective when verifying safety-critical systems.(More)