Final answer:
In the multi-server queuing model, each customer is to be assisted by any available agent. While this idea aims to reduce wait times, the model does presume unrealistic, consistent traffic and single-customer arrivals.
Step-by-step explanation:
In a multi-server queuing model, the essential assumption is that each customer can be attended to by any available agent. The key characteristic of a multi-server model is that it provides multiple service channels, which increases the likelihood that service will be immediate if a channel is open. This helps reduce wait times when the system is busy. However, there are limitations to the multi-server queuing theory model, such as the assumption that customers arrive one at a time and that the traffic is consistent throughout the day, which might not reflect a real-world scenario where arrival patterns can be more erratic and the number of customers can vary widely during peak and off-peak hours.