Re-engineering a credit card authorization system for maintainability and reusability of components - a case study

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 re-usability 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 re-engineering project has been successfully transferred to the company.