The current call center format has two lines: one for customers who want to place an order and one for customers who want to report a problem. Each line is served by one specialized customer service representative. The call center is staffed so that at any given time, there is one representative taking customer orders and one representative addressing customer problems. On average, there is a new customer who wants to place an order every two minutes, exponentially distributed. Similarly, there is a new customer needing to address a problem every two minutes, exponentially distributed. The call center staffers are fast and can on average complete one call of either type in $75$ seconds, with a standard deviation of $30$ seconds. Each call center staff member is paid $$15$ per hour. The estimated cost of a customer waiting for a representative is $$20$ per hour due to lost goodwill and negative word of mouth.