No matter how high-capacity call centers are, they can never fully meet the incoming call density. Therefore, some of the customers have to wait in line. No matter how normal this process is, a long wait will make all customers impatient and angry. There are two ways to overcome this density. The first is to produce a quick solution. The second is to solve the problem of the calling customer in a single call and not having to call again. Therefore, the call center employee is expected to solve the customer's situation at the end of the call.