Modeling fault tolerance tactics with reusable aspects

This paper is part of a larger research project aiming to integrate dependability analysis in the early phases of the software development process, by generating and analyzing Stochastic Reward Net (SRN) models from UML software models. The paper is focused on adding fault tolerance to software designs by using Aspect-Oriented Modeling. More specifically, single-version fault tolerance tactics are modeled as generic reusable aspects annotated with dependability attributes. The paper describes how the generic aspects are instantiated, bound to the context and composed with the original UML software model. Since an SRN analysis model is generated from the UML model, the paper discusses what kind of transformation rules are necessary for translating fault tolerance tactics from UML to SRN, giving as an example the transformation rule for checkpoint synchronization. A case study illustrates the proposed approach.