Fuzzy quality analysis of web services implemented in virtualised environment

The paper describes the quality analysis of web services implemented in virtualised environment. It takes into account the reliability and performance aspects of software and hardware elements of the web service. The presented state-transitional model considers the reconfiguration process to maintain the continuity of business services. The reconfiguration is based in on the redeployment of virtual machines so for some time the system operates in a degraded state. Author propose two quality measures based on the web service availability and maximum handled requests calculated at each of degradation levels. Moreover, authors proposed to model the web service reliability parameters by fuzzy numbers. A method for calculating fuzzy membership functions of quality measures are also presented.