Availability Analytical Model for Web Services of an E-learning Development Platform

E-learning started to attract a lot of attention from researchers as well as practitioners recently. Many of the existing architectures of e-learning systems are mainly based on plain client-server or peer-to-peer architectures and are therefore suffering from drawbacks like poor scalability or complicated interchange of content. In this paper, we first present a distributed, service-oriented soft architecture for e-learning development platform based on Web services, and design the availability model for web services. Secondly, according to queuening theory, we obtain closed form equations of the availability of web services, from which sensitivity analyses are conducted in detail. Finally, the result achieved form this model can help designers of the E-learning development platform system find the right tradeoffs for achieving availability of users expected while providing acceptable levels of performance.