Grid computing offers many scientific and commercial benefits, but also many technical and organisational challenges. This has led to many research areas in traditional distributed systems directing their efforts on to grid systems. Amongst the challenges for grid computing is the need to provide reliable quality of service to end users. Grid computing promises much for high performance computi...

Local area networks are representative of a growing class of distributed systems which demand more sophisticated methods and tools to evaluate system behavior in the presence of faults. In particular, since they are likely to exhibit degradable performance, the concept of performability can provide more re ned assessments of their ability to perform under fault and error conditions. This paper ...

Computer and communication systems are designed to meet a certain speciied behavior. The procurement of metrics to establish how well the system behaves, that is, how closely it follows the speciied behavior , is the objective of quantitative analysis. Traditionally, performance and dependability evaluation are used as separate approaches to provide quantitative gures of system behavior. Perfor...

Model checking has been introduced as an automated technique to verify whether functional properties, expressed in a formal logic like computational tree logic (CTL), do hold in a formally-specified system. In recent years, we have extended CTL such that it allows for the specification of properties over finite-state continuous-time Markov chains (CTMCs). Computational techniques for model chec...

Security authentication verifies the identity of an entity in a networked system. Risk assessment of an authentication mechanism is paramount to assure the security of a system, especially for today's ubiquitous deployment of Radio Frequency Identification (RFID) systems. Though experts in performability engineering have extended modelbased evaluation techniques to assess security attributes su...

Safety-critical systems are increasingly difficult to comprehend due to their rising complexity. Methodologies, tools and modeling formalisms have been developed to overcome this. Component-based design is an important paradigm that is shared by many of them. It helps to master the overall complexity while in addition allowing for reusability. Furthermore, it easily supports the common issues i...

The authors describe a methodology for evaluating the performability (combined performance and reliability) of large communications networks. Networks are represented by a 4-level hierarchical model, consisting of traffic matrix, network graph, “components” representing failure modes, and reliability information. Network states are assignments of modes to the network components, which usually r...

With the increasing complexity of multiprocessor and distributed processing systems, the need to develop efficient and accurate modeling methods is evident. Fault tolerance and degradable performance of such systems has given rise to considerable interest in models for the combined evaluation of performance and reliability [l], [2]. Markov or semi-Markov reward models can be used to evaluate th...

The primary topic of this report is ‘metrics.’ More specifically, we discuss quantitative metrics for evaluating Internet services: what should we quantify, monitor and analyze in order to characterize, evaluate and manage services offered over the Internet? We argue that the focus must be on quality-of-experience and, what we call, quality-of-business metrics. These QoE and QoBiz metrics quant...

Nowadays, both of network operators and regulators are concerning about adding new end user's features. These features may be added to future networks and current deployed ones. In order to achieve that, network performance as well as its availability must be taken into consideration side-byside for having a successful network operation. The process of coupling of them will be beneficial in the...