Customer Relationship Systems are large systems that take a lot of time and resources to properly implement and then operate. They are in the same league as Enterprise Resource Planning (ERP) systems, and the size and scope of some of the failures with these systems are legendary.
Some failures, however, are not as dramatic or obvious as the more famous implementation failures. Sometimes, the new system comes into production, and then the users work with it and it can take a long time before the realization creeps in that the system is not delivering on its promise, perhaps that it is draining the enterprise of its resources and not delivering results.
This calls for ongoing vigilence and the implementation of evaluation systems, carried out by groups with a degree of independence from the implementation, to determine whether the system needs to be tweaked or even replaced.
An article in E-Commerce News addresses this issue for CRM systems and offers some practical advice.