Software Product-Lines: What To Do When Enumaration Won't Work

The history of research on the development of program-families is briefly reviewed. Two distinct problems, configuration-management and family-design are identified. It is explained that, while software configuration-management is not fundamentally different from configurationmanagement for other products, in practice, inadequate attention to family-design exacerbates all problems associated with developing and maintaining program families. It is suggested that although enumeration is useable for configuration-management, product-line design by enumeration is not generally