Prototyping practices are widely used. Requirements engineers develop screen prototypes with paper or HTML. However, feedback on the prototypes has limited effectiveness. Screen prototypes are mainly useful for reviewing only user interface requirements. To cope with this situation, we propose a requirements validation approach using models and prototyping (ReVAMP). This approach provides customers with a set of requirement models and a system prototype generation tool for trial use. A generated system prototype is implemented with both business application features and access control features. Thus, customers could give requirements engineers more practical feedback on requirements for not only a user interface but also other aspects of a target system. To evaluate the proposed models and tool, we introduce two business information system development projects in which the proposed approach was applied.