I did a research case-study on this project and the FBI system as part of a study on enterprise architecture failures. The principal purpose of the CityTime system was to prevent city employees from filling out and signing time cards for their coworkers. In other words, reduce fraud in the time keeping system and thereby lower city costs (payroll is one of, if not the, biggest expense for the city government).

Outside of the fantastic irony of the situation, that requirement was interpreted to mean a fairly high level of security and auditing over the city employees' time keeping activities. This meant system integrated biometric scanners, one-time keys, end-to-end encryption etc...making for a fantastically complicated architecture.