Number of doctors. With respect to the environmental factor ‘number of doctors’, four types of systems are discussed in literature. A first distinction can be made between single-server systems and multi- server systems. Single-server systems are systems where, evidently, a single doctor serves the patients. These single-server systems are most often studied in literature. The system becomes more complicated when multiple doctors serve the patients. We call such systems multi-server systems. Within these multi-server systems, a second distinction can be made. A first system is a system in which patients, arriving at the clinic have an appointment with a specific doctor. In such systems, every doctor has his or her own, independent list of patients (Xxxxxx et al., 1973; Cox et al., 1985). However, while individual doctors may work independently, they often share common resources such as space, personnel and equipment. Xxxx, Xxx, & Xxxx (2010) examine such a setting. Alternatively, systems exist in which patients arriving at the clinic wait in a single, common queue and are assigned to the first doctor available. Such systems are studied in Babes & Xxxxx (1991), Xxx & Xxx (1998a, 1998b) and Xxx (2015). Although such single, common queues have been proven to lead to shorter wait times, systems in which each doctor has an independent list of patients are often preferred in practice. That is understandable both from the doctor’s and patient’s perspective as it allows to build a one-to-one relationship. Moreover, from a more practical point of view there’s the advantage that in this case the doctor is familiar with the patient’s medical record. The third and final type of multi-server systems found in literature is more complex. In addition to a single, common queue it also models the assignment of patients to different types of medical staff members based on their probability of requiring a certain type or skill of staff (Xxxxxxx & Veral, 2003). This situation is studied in (Xxxxxxx et al., 2001).
Number of doctors. Clinic sessions are divided in morning and afternoon sessions. The number of doctors holding consultation at the same time varies. On average, per morning or afternoon session, there are three to four medical specialists and four to five resident physicians working at the dermatology department. Each of these medical specialists and resident physicians has his or her own list of patients for a given clinic session. Patients that arrive at the department have an appointment with a certain doctor and consequently queue to see that particular doctor. The dermatology outpatient clinic thus operates under a multi-server system with every doctor working independently, having his or her own queue of patients.
