A rigorous approach to software development is followed in developing a program to control the various components and versions of systems. This particular approach to systematic program development is known as the Vienna Development Method (VDM). This paper documerits the author's early experiences with VDM on a small, yet nontrivial, application. The functional specification of the version control system is presented in detail. Design decisions taken for a prototype implementation are also included. The version control program developed is based upon the Gandalf System Version Control Environment of Carnegie-Mellon University. Both that system and the subject of this case study support the most common forms of component interdependency relations, and methods of system evolution.