Quality, Cost and Delivery are the most crucial factors to be maintained in developing software systems in the industry. Recently, in addition to these factors, customer satisfaction is getting increasing attention. How to acquire customer?s needs and reflect them quickly into the software products with least effort becomes important issues. The weight of costs for developing software systems is shifting from coding effort to analysis effort. This paper summarizes the step-wise developments of the web-based application systems that we had experienced in the last several years. Having developed the toolkit which automatically generates application programs from specifications, it was applied to the software product line systems. Furthermore it is integrated with the questionnaire systems. The shift behavior of our application development processes and the lessons we learned to produce the efficient customized software application systems while offering substantial savings in time and cost are described.