Comparison of two alternative policies to reduce no-show in appointment system

It's common practice for patients to make an appointment in advance before seeing the doctor. This paper compares two alternative policies to reduce no-show for single server appointment system with exponentially distributed service time, the overbooking policy and open access policy. A specified number of patients call for an appointment before the scheduled day, but may cancel the booking or don't show up under the overbooking policy. Two types of open-access policies are taken into consideration: same-day and same-or-next-day, in which a random number of patients call for the appointment for the same day or the next day. System performances are compared when the expected workloads are the same for both policies. The numerical results indicate the superiority of open-access polices are not so explicit as the results under deterministic assumption. Same-day AS system has a threshold in terms of total operational costs, after which it outperforms the overbooking system; same-or-next-day system is always preferable except when no-show probability or the weight of the patients is low.