Queuing Theory is a conceptual framework used to analyze and optimize the queuing or waiting process in the context of a service system. In queuing theory, customers arrive at the service server from a source, where they can immediately start service or wait in a queue if the server is busy. Once service is complete, the server automatically serves the next customer in the queue. In queuing analysis, customer arrival time is represented by the inter-arrival interval while service is measured by service time per customer. Even though queuing theory is a simple method, it can become complex if done manually because it requires high accuracy. Using Microsoft Excel is the right tool because it makes it easier to carry out calculations accurately. Excel displays the calculation results in spreadsheet form so that the calculation stages can be more easily understood..