Stochastic activity networks (SANs) are a stochastic generalization of Petri nets. The original definition of SANs has been used as a modeling formalism in several well-known and powerful modeling tools. SANs have been used to evaluate a wide range of systems, mainly for dependability and performability evaluation purposes. SAN models have not been considered in the definition of the Petri net ...

A large scale open source solution composed of several open source softwares is now attracting attention as the next-generation software development paradigm because of the cost reduction, quick delivery, and work saving. The testing phase of open source solution means the binding testing and system testing. Generally, it makes no sense to perform the unit testing of open source solution, becau...

Digital telecommunication networks represent a fusion of concepts, techniques, and technologies from the fields of both communication and computing. The evaluation of such systems can likewise draw on methodologies which have evolved in both disciplines, bringing them together in a fashion that is suited to the needs of integrated services digital networks. With this aim, we discuss how quality...

We consider the impact of different communication architectures on the performability (performance + availability) of cluster-based servers. In particular, we use a combination of fault-injection experiments and analytic modeling to evaluate the performability of two popular communication protocols, TCP and VIA, as the intra-cluster communication substrate of a sophisticated Web server. Our ana...

The high expectations of performance and availability for wireless mobile systems has presented great challenges in the modelling and design of fault tolerant wireless systems. The proper modelling methodology to study the degradation of such systems is so-called performability modelling. In this paper, we give overview of approaches for the construction and the solution of performability model...

We propose a two-phase methodology for quantifying the performability (performance and availability) of cluster-based Internet services. In the first phase, evaluators use a fault-injection infrastructure to measure the impact of faults on the server’s performance. In the second phase, evaluators use an analytical model to combine an expected fault load with measurements from the first phase to...

SRAM-based FPGAs are increasingly popular in the aerospace industry due to their field programmability and low cost. However, they suffer from cosmic radiation induced Single Event Upsets (SEUs). In safety-critical applications, the dependability of the design is a prime concern since failures may have catastrophic consequences. An early analysis of the relationship between dependability metric...

This paper introduces a new benchmark tool for evaluating performance and availability (performability) of networked storage systems, specifically storage area network (SAN) that is intended for providing block-level data storage with high performance and availability. The new benchmark tool, named N-SPEK (Networked-Storage Performability Evaluation Kernel module), consists of a controller, sev...

In this paper we present a simple model that combines the failure to meet deadlines with hardware/software failures in computing the reliability of a real-time system. We define the performability as the probability of meeting deadlines by real-time tasks in the presence of hardware and software failures. Deadline driven schedules rely on worst-case task execution time. This may be necessary fo...