Since Internet dominated the world, the World Wide Web platform is used as a type of middleware providing a common platform for Intranetbased and Internet-based application development. Web-based applications have become more complex and demanding, in order to fulfil extended user requirements. In this paper, we propose a systematic approach for the configuration, modification and performance evaluation of web-based systems. Its contribution involves the employment of knowledge-based techniques for the design of web-based systems and the description of problems encountered and the solutions proposed. Emphasis is given on the extendable modelling scheme used to depict web-based application functionality and estimate application requirements from the network infrastructure. Web-based system architectures are designed and evaluated using IDIS environment.