Using a stochastic well-formed net model for assessing a decentralized approach to configuration management

Traditional support tools for software engineers, normally based on a client–server architecture, are unsuitable to deal with the new issues emerging from the current (and future) cooperative work scenarios (where connectivity is intrinsically transient, the number of interacting partners dynamically changes, etc.). This paper presents a quantitative assessment of a fully decentralized, peer-to-peer, cooperative infrastructure. Stochastic Well-formed Nets (SWNs) modeling the new peer-to-peer architecture, and a traditional (client–server) one, are developed and analyzed: we used SWNs for their ability to directly exploit the symmetries intrinsically present in the modeled systems in order to reduce the complexity of analysis/simulation. The goal is to compare the impact of the two alternative protocols on the collaborative work. The paper focuses on methodological issues concerning choice of an appropriate model abstraction level, adoption of a compositional modeling approach, and mainly, management of model solution complexity. Some performance figures of interest (selected among a number) are also presented and discussed.