Dissertation (MSc Information Technology)This study tests the patient appointments waiting time by using computer simulation which was carried out at the Iringa Referral Hospital (IRH). The study is triggered by the fact that in most Tanzania public hospitals like IRH, patients queue for a long time to get services. Basically, such situation leads to poor quality of service that leaves many patients unsatisfied. The study analyzed four experiments and critically evaluated appointments queuing model. Three models used to formulate and test the patient appointments queuing model. The model tested the waiting time and number of the patients to be attended as in experiment I, II, III and IV for one, two, three and four doctors respectively. The study examined the contributions and applications of queuing theory in the field of healthcare. The study summarizes a queuing theory results in the following areas: waiting time, utilization analysis, appointment systems and number of patients attended for each experiment. The system employed by Arena computer simulation to analyze proposals for improvement and optimization. The goal is to provide sufficient information to analysts who are interested in using queuing theory to model a healthcare process and want to locate the details of relevant models. Thus, this appointments queuing model is useful for the Tanzanian hospitals to arrange schedules with patients for the various services and research area of hospital simulations and modelling.