To shorten the time needed to generate or modify software by provid ing steps wherein customer data in respective features of customized service software are set and customer-oriented service software oriented to service users is generated.

In a combining process 16 for service features, the features are combined covering essential features and selective features corresponding to object service software to be generated to complete an inclusive flow 17 (S2). The essential features and desired selective features in the inclusive flow 17 are selected and registered 19 on a service management screen 18 to generate the customized service software 20 oriented to service providers. The customized service software 22 oriented to service users is generated (S4) by making respective in-feature customer data settings 21 in the software 20.