A manager wants to determine the number of kanbans to use in a new process for a part. The process will have a usage rate of 80 pieces of the part per hour. Because the process is new, the manage has assigned a safety factor of 1.0. Each container holds 45 pieces and a kanban will take an average of 75 minutes to complete a cycle. flow many kanbans should be used? As the system improves, will more or fewer kanbans be required? Why?