Complex COTS-based software systems: practical steps for their maintenance

This paper makes pragmatic recommendations for the maintenance of complex COTS-based systems. We first enumerate the issues that can arise in systems that rely on COTS products, whether in operational systems themselves or in the support systems used to create, modify, or test operational systems. We then suggest principles by which maintenance practice for such systems can be facilitated, particularly for those safety-critical systems for which significant risk is present if they fail. These principles aim at making explicit, during system creation, the COTS-related development practices upon which successful system maintenance will subsequently depend. They also depend on a reasonable means of determining, during system maintenance, how much risk is acceptable in using new releases of COTS products. Copyright © 2000 John Wiley & Sons, Ltd.