Complex schedules, with many appointment types, times, and restrictions, can actually increase total delay in the system because each appointment type and time creates its own differential delay and queue. Reducing the complexity ultimately decreases system delays.

The majority of clinical practices use many appointment types and lengths in an effort to exert some control over the schedule. The belief is that limiting the number of a certain type of appointments scheduled on a daily basis, or assigning patients to different times or types of appointments, will improve access in the practice. Queuing theory, however, suggests that reducing the number of separate "lines" or "queues" for different services creates more flexibility in the system and reduces delays associated with distinct queues. Therefore, having many appointment types actually increases total delay in the system because each appointment type creates its own differential delay and queue.