A credit card authorization system (CAS) is a large information system
performing diverse activities such as purchase authentication, balance
transfer, cash advances, etc. One characteristic of CAS is its frequent update to
satisfy the needs of customers and newly enforced governmental laws. Thus,
CAS should be designed to minimize the effects of updates, for which high reusability
of the CAS components is desired. In this paper, we present our experience
of re-engineering CAS based on a feature model for improved reusability
of components, which alleviates the difficulty of system maintenance.
The result of this project has been successfully transferred to the company.