Generalized observational slicing for tree-represented modelling languages

Model-driven software engineering raises the abstraction level making complex systems easier to understand than if written in textual code. Nevertheless, large complicated software systems can have large models, motivating the need for slicing techniques that reduce the size of a model. We present a generalization of observation-based slicing that allows the criterion to be defined using a variety of kinds of observable behavior and does not require any complex dependence analysis. We apply our implementation of generalized observational slicing for tree-structured representations to Simulink models. The resulting slice might be the subset of the original model responsible for an observed failure or simply the sub-model semantically related to a classic slicing criterion. Unlike its predecessors, the algorithm is also capable of slicing embedded Stateflow state machines. A study of nine real-world models drawn from four different application domains demonstrates the effectiveness of our approach at dramatically reducing Simulink model sizes for realistic observation scenarios: for 9 out of 20 cases, the resulting model has fewer than 25% of the original model's elements.