Probability distribution of the model
Alice Tanner is a nurse on the night shift from 10:00 P.M. to 6:00 A.M. at Community Hospital. She has 15 patients for whom she is responsible in her area. She averages two calls from each of her patients every night on average (Poisson distributed) and she must spend an average of 10 minutes (exponentially distributed) with each patient who calls. Nurse Tanner has indicated to her supervisor that, although she has not kept records, she believes her patients must wait about 10 minutes on average for her to respond and she has requested that her supervisor assign a second nurse to her area. The supervisor believes 10 minutes is too long for a patient to wait but she does not want her nurses to be idle more than 40% of the time. Determine what the supervisor should do.