This invention relates to the development of a business program in an XML driven architecture. First, XML data corresponding to a form screen is analyzed and a business class corresponding to a tag included in the XML data is specified. Then, by referring to a business class manager in which the business classes to be created are registered, it is judged whether or not the specified business class has not been registered in the business class manager, and if the specified business class has not been registered in the business class manager, the specified business class is registered in the business class manager. After this, each of the business classes has to be specifically programmed. On the other hand, at the execution time of the programmed business classes, XML data including tags corresponding to data inputted or selected for the form screen is obtained, and the business classes that correspond to the tags included in the XML data and are programs to carry out a processing relating to the tags. Then, the specified business classes are called among the business classes that are defined in advance and loaded in a memory.