Please answer the following question by using the concepts introduced in chapter 9(Variability and Its Impact on Process Performance: Waiting Time Problems)

Many companies including banks have customer service departments that receive a large number of calls (and inquiries) from their customers on a daily basis. One of the biggest challenges for such departments is to reduce the waiting time that their customers experience before they get their issues resolved (needless to say that waiting time may have a direct relationship with customer dissatisfaction). Explain what factors can affect the waiting time length in a typical customer service operation? And, what are the potential ways to reduce the wait time?