Care, feeding and growth of software systems

The attention of practitioners and proponents of the use of formal methods has for a long time been focused on relatively small and complex applications. The hardware domain lends itself well to this and it has therefore been the target of some of the most significant applications of formal methods. The software applications that have typically been considered are for safety-critical systems though there have also been some experiments in the specification of parts of large subsystems, such as CICS.