Configuration is a recurring problem in many domains. In our earlier work, we focused on architecture-level configuration of large-scale embedded software systems and proposed a methodology that enables engineers to configure products by instantiating a given reference architecture model. Products have to satisfy a number of constraints specified in the reference architecture model. If not, the engineers have to backtrack their configuration decisions to rebuild a configured product that satisfies the constraints. Backtracking configuration decisions makes the configuration process considerably slow. In this paper, we improve our earlier work and propose a backtrack-free configuration mechanism. Specifically, given a cycle-free generic reference architecture model, we propose an algorithm that computes an ordering over configuration parameters that yields a consistent configuration without any need to backtrack. We evaluated our approach on a simplified model of an industrial case study. We show that our ordering approach eliminates backtracking. It reduces the overall configuration time by both reducing the required number of value assignments, and reducing the time that it takes to complete one configuration iteration. Furthermore, we show that the latter has a linear growth with the size of the configuration problem.
