An Evaluation Model for Dependability of Internet-Scale Software on Basis of Bayesian Networks

TLDR: The model analyzes the structure of Internet-scale software and establishes an evaluation system of dependability for Internet- scale software including static metrics, dynamic metrics, prior metrics and correction metrics and integrates subjective and objective factors which impact on system quality.

Abstract: Internet-scale software becomes an important mode of constructing software systems with the development of internet. Open, dynamic and uncontrollable Internet environment makes dependability evaluation of Internet-scale software very important. It is lack of a dependability evaluation model that analyzes system architecture from the most foundational elements and integrate aspects that impacts on the system, such as the technical, organizational, decisional and human aspects. This paper proposes an evaluation model of dependability for Internet-scale software on the basis of Bayesian Networks. The model analyzes the structure of Internet-scale software and establishes an evaluation system of dependability for Internet-scale software including static metrics, dynamic metrics, prior metrics and correction metrics. It integrates subjective and objective factors which impact on system quality. In this paper, we build Bayesian Network according to the structure analysis and refer to a bottom-up method that use Bayesian reasoning to analyses and calculate entity dependability and integration dependability layer by layer. A unified dependability of the whole system is worked out and is corrected by objective data. The analysis of experiment in a real system proves that the model in this paper is capable of evaluating the dependability of Internet-scale software clearly and objectively. Moreover, it offers effective help to the design, development, deployment and assessment of Internet-scale software.