Real world dependable distributed systems are often heterogeneous, not only in their physical composition, but also from a modeling and analysis perspective. Indeed, different components may be modeled by using the most suitable modeling formalism and multi-solution strategies may be applied to analyze the resulting multi-formalism model since no single solution method is adequate to solve all sub-models. In this paper we present the architecture of an extensible multi-formalism framework for the modeling and design of distributed dependable system. We show that the process needed to solve/analyze a model expressed through different formalisms may be described as it were a business process and executed by means of a workflow engine. We apply the proposed technique to a fault tolerant remote SCADA (Supervisory Control And Data Acquisition) system.