This talk begins with a description of "the software configuration management problem", then focuses on the key technical difficulties that must be overcome in order to manage the development of a software system of practically any size (that is, tens of millions of source-code lines). It then presents the Vesta approach and reports our experience with a highly functional prototype system. The talk concludes by describing how the Vesta system presently under construction provides reproducible, incremental construction of arbitrarily large software systems.