Introducing variable-interval appointment scheduling rules in service systems

The general practice in implementing an appointment scheduling rule (ASR) is to enforce a certain rule, such as ‘block appointment’, to schedule customer arrivals in service systems. There are several commonly used ASRs that have been used in such service systems as public and private clinics and restaurant reservations, most of which tend to minimize the idle time or optimize the utilization rate of the service facility while neglecting customers’ waiting times. One commonly used ASR in real-world service systems, which schedules several customers to arrive at the start of each service session, tends to induce long customer waiting time, but manages to keep the facility idle time fairly low. Introduces an ASR to reduce customers’ waiting time considerably while increasing the facility idle time at a manageable minimum. Evaluates environmental factors that may affect the performance of ASRs, such as the probability of no-shows, the coefficient of variation of service times, and the number of customers per service session. Discusses several exceptional situations such as walk-ins, seasonality of customer arrivals, and multiple-priority/queues.