Abstract
Informal and semi-formal specifications are commonly adopted for requirements engineering (RE), especially for customer-oriented system development projects, but their validity with respect to the user's requirements is usually difficult to perform. The common reason for the difficulty is that the specifications are often misinterpreted by the stakeholders due to the ambiguity of the natural language or graphical notation used in writing the specifications. This paper describes a tool to assist the animation of informal and semi-formal specifications intuitively and comprehensively for their validation. The underlying animation principle is called SOFL Requirements Specification Animation Framework (SOFL-RSAF). The framework integrates specification animation into the SOFL method for constructing specifications and is supported by a prototype add-in tool.