Moe Electronics produces APP switches for NASA. The current assembly capacity is 100 switches per hour. It takes 40 minutes to receive the necessary component from the previous workstation. Completed switches are placed in a rack that will hold 25 switches. The rack must be full before it is sent on to the next workstation. If Moe uses a safety factor of 5 percent, how many kanbans are needed for the APP switch assembly process?