EZS is a small fast food outlet serving a mainly freshly prepared, customizable line of sandwiches. It is supplemented with an assortment of drinks, light salads, seasonal fruit and snacks. A customer joining the line makes a sandwich selection by consulting the billboard, and marks her selection on a customized form. She then hands the form to an assembler who produces the sandwich. The customer does not wait for the sandwich to be assembled, but proceeds directly down the line to select additional items onto her tray. Next, the customer proceeds to pay at the cash register. Finally, (after the payment is completed) she collects her prepared sandwich at a designated location. Selecting the sandwich and marking the form takes 50 seconds. Assembling the sandwich requires 90 seconds. Selecting additional items takes 40 seconds. Paying at the cash register requires 30 seconds. Collecting the prepared sandwich requires 20 seconds. Hint: Draw a process flow-chart.

Another improvement option considered is limiting the number of additional items available, thereby reducing the expected time of making a selection from 40 to only 30 seconds. What is the expected effect on the theoretical flow time of the process?

Question options: a) It will decrease by 20 seconds b) It will not change c) It will increase by 10 seconds d) It will decrease by 10 seconds