Communication System
A Unified Performability Evaluation Framework for Computer and Communication Systems
A Unified Performability Evaluation Framework for Computer and Communication Systems
Aad P. A. van Moorsel Boudewijn R. Haverkort
Tele-Informatics and Open Systems University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands moorsel@cs.utwente.nl
Abstract
In this paper we discuss a unified approach towards model-based quantitative evaluation of both computer systems and communication systems. In the area of fault-tolerant computer systems, dependability evaluation has been recognized as being a topic of importance, both to judge a system on its merits and to provide trust in the actual dependability of the system. In communication systems, the need for identifying and evaluating quality of service parameters is becoming more and more apparent because of increasing demands on for instance speed and availability. In this paper we construct a framework, the so-called performability evaluation framework, within which the quantitative evaluation of both types of systems can be discussed. The framework closely resembles the performability framework introduced by Meyer [18]. We present a general view, a system view and a modelling view on performability evaluation, leading to a framework which naturally fits known measure definitions, modelling methods and solution techniques. We will especially discuss the importance of evaluating useful performability measures. In this respect we will distinguish between system measures and task measures. Task measures directly relate to evaluation of the service, and we will argue that in performability evaluation task measures should be evaluated. We relate the performability evaluation framework with known concepts in both the areas of computer and communication systems.
1. Introduction
In this paper we develop the so-called performability evaluation framework (PEF). The goal of the PEF is twofold. Within the PEF we motivate our
A Unified Performability Evaluation Framework for Computer and Communication Systems
Aad P. A. van Moorsel Boudewijn R. Haverkort
Tele-Informatics and Open Systems University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands moorsel@cs.utwente.nl
Abstract
In this paper we discuss a unified approach towards model-based quantitative evaluation of both computer systems and communication systems. In the area of fault-tolerant computer systems, dependability evaluation has been recognized as being a topic of importance, both to judge a system on its merits and to provide trust in the actual dependability of the system. In communication systems, the need for identifying and evaluating quality of service parameters is becoming more and more apparent because of increasing demands on for instance speed and availability. In this paper we construct a framework, the so-called performability evaluation framework, within which the quantitative evaluation of both types of systems can be discussed. The framework closely resembles the performability framework introduced by Meyer [18]. We present a general view, a system view and a modelling view on performability evaluation, leading to a framework which naturally fits known measure definitions, modelling methods and solution techniques. We will especially discuss the importance of evaluating useful performability measures. In this respect we will distinguish between system measures and task measures. Task measures directly relate to evaluation of the service, and we will argue that in performability evaluation task measures should be evaluated. We relate the performability evaluation framework with known concepts in both the areas of computer and communication systems.
1. Introduction
In this paper we develop the so-called performability evaluation framework (PEF). The goal of the PEF is twofold. Within the PEF we motivate our