Nowadays, one of the main challenges in developing different systems, is obtaining reliable ones. So, preliminary studies of problematic components that convert the system from reliable to unreliable need to be done. This paper is focused in evaluating one of the nonfunctional characteristics like the reliability of web applications deployed on cloud computing, since it plays an important role in evaluating the system performance. The main goal consists on developing a dynamic model for the evaluation of web application's reliability using DFT technique. As a case study in order to demonstrate the feasibility of this approach are used online payment systems in e-commerce hosted on a cloud platform. The results obtained reveal that this is a good way in studying the reliability of the systems. Under specific system conditions with minimal functional resources on the cloud platform, cloud impact on system unreliability is twice the impact of application's type.
web application, cloud computing, Dynamic Fault Tr- ees (DFT), reliability, E-Commerce