Abstract: Service delivery systems, such as restaurant, emergency department and airport checking terminals are faced with the tough task of processing an increasing demand of customers. At the same time, customers have to decide finally either to accept or reject. However, the customer can order to reprocess the service before making the final decision. Single-server, such as M/G/1 system is simple and can be utilized as preliminary models. Modeling of the systems state using Markov chain approach and queuing models provides a more rigid approach to better understand the dynamics of the service delivery system. Therefore, this study proposes a conceptual model using of Markov chain approach combined with M/G/1 queuing model to optimize general service delivery systems. To illustrate the model, a numerical example is introduced and solved and the optimum system’s parameters are determined. The obtained results showed a high sensitivity of net profit to the mean variation, service and arrival rates while the effect of other parameters is not high.