Rate Lifting for Stochastic Process Algebra: Exploiting Structural Properties

Abstract

. This report presents an algorithm for determining the unknown rates in the sequential processes of a Stochastic Process Algebra (SPA) model, provided that the rates in the combined flat model are given. Such a rate lifting is useful for model reengineering and model repair. Technically, the algorithm works by solving systems of nonlinear equations and – if necessary – adjusting the model’s synchronisation structure without changing its transition system. This report contains the complete pseudo-code of the algorithm. The approach taken by the algorithm exploits some structural properties of SPA systems, which are formulated here for the first time and could be very beneficial also in other contexts.