Specification and Description Language (SDL) is a formal object-oriented language for modeling real-time interactive systems. It is an International Telecommunication Union (ITU) standard.A software architecture is the structure of a program including a set of inter-communication components. These components are often independently executable super objects. We use the architecture design to answer questions such as how thesuper objects fit together and how to reuse them. This paper investigates the feasibility and benefits of using SDL to represent the dynamic aspect of the software architectures. It includes a methodology and an accompanying tool, Workflow-to-SDL-Transformation (W2S), for deriving software architectures in SDL from an originally informal use case flow definitions.The focus of research is in telecom domain, many of which are real-time interactive systems. We applied our method to a partial telecom system. The experimental results are collected and presented. Our result shows the feasibility and benefits of representing the dynamic of software architecture in SDL.