Final answer:
In multiple-server models, two or more independent servers serve a single waiting line. Such systems can be analyzed using queuing theory, which takes into account customer arrival and service rates.
Step-by-step explanation:
In multiple-server models, two or more independent servers in parallel serve a single waiting line. This arrangement is found in various service-oriented businesses where it is necessary to handle more than one customer simultaneously to reduce waiting times and avoid bottlenecks. For example, in a bank that has a single queue for customers, there can be several tellers (servers) available to serve the customers. The efficiency of such a system can be analyzed using queuing theory, which helps in understanding and improving service systems.
Considering the information provided as a reference, we are given that one customer arrives every two minutes on average. Using this rate, on average, it would take six minutes for three customers to arrive. This piece of information is valuable in calculating the arrival rate and service rate necessary to determine the queue length and waiting time in a multiple-server model.