The maintenance of enterprise application software at a customer site is a potentially complex task for software vendors. This complexity can unfortunately result in a significant amount of work and risk. This paper presents a case study of a product software vendor that tries to reduce this complexity by integrating product data management (PDM), software configuration management (SCM), and customer relationship management (CRM) into one system. The case study shows that by combining these management areas in a single software knowledge base, software maintenance processes can be automated and improved, thereby enabling a software vendor of enterprise software to serve a large number of customers with many different product configurations.