There are a number of commercial products available that support problem report tracking and a few that have both automated problem reporting and file management integrated into a single system. The integrated problem reporting and file management systems automatically associate file updates with the problems being corrected, thereby providing the most reliable and easiest way to ensure that the corrective action system is closed-loop. Enough so that problem reports are not lost and the work can continue even when key people leave. The idea behind cost control, as it applies to software configuration management, is that not all problems need to be fixed or may be prohibitively expensive to fix. You may decide that you can live with the broken gauge, as long as the odometer works and you get gas every 200 miles.
Similar situations exist for software.
Mechanically, it is relatively easy to implement cost control into an SCM process that already has integrated, automated file management and problem reporting. Costs are controlled by prohibiting file check-out unless a fix to a problem or an enhancement has been authorized. The human and organizational considerations for implementing cost control are harder and a little more complex. In many organizations, especially in manufacturing, cost considerations are strictly the domain of the managers. However, given the nature of software and software engineers, there needs to be more of a partnership forged between the managers and the software engineers for successful cost control.