I agree with many others here in that a good management system need to be well maintained; the frequency of the maintenance largely depends on the size of the environment as well as the rate of change in the environment. On the flip side, you shouldn't need a team of people or to be constantly hiring vendor professional services to keep the system up and running properly; if this is the case you should probably consider a different management system.
Unfortunately management (at least not my management) doesn't seem to understand the fact that these systems require constant care and feeding. I am regularly questioned when I spend time cleaning and maintaining our management systems.