1. You decide to add an additional oven to the process. The number of dozens of cookies that can be produced per hour will increase to:

12 dozen because we doubled the capacity of the baking step.

7.5 dozen because the bottleneck step moved to Wash+mix & Spoon (i.e. you).

10 dozen because we doubled the capacity of the baking step but it will still be inefficient.

6 dozen because the cookies will not cool fast enough.
 

You and your roommate already own all the necessary capital equipment: a high-capacity professional-grade electric mixer, cookie trays, and spoons. Your apartment has a small oven that will hold one tray at a time. Your landlord pays for all the electricity. The variable costs, therefore, are merely the cost of the ingredients (estimated to be $0.60/dozen), the cost of the box in which the cookies are packed ($0.10 per box; each box holds a dozen cookies), and your time (what value do you place on your time?). A detailed examination of the production process, which specifies how long each of the steps will take, follows. The first step is to take an order, which will be extremely fast and 100% accurate, since your roommate has devised a method using the campus e-mail system to accept orders and to inform customers when their orders will be ready for pickup. Because this runs automatically on your personal computer, it does not take any of your or your roommate's time. Therefore, this step will be ignored in further analysis. You and your roommate have timed the necessary physical operations. The first physical production step is to wash out the electric mixer's bowl and beaters from the previous batch, add the ingredients to the bowl, and turn on the mixer to mix the ingredients. The electric mixer can hold and mix ingredients for up to three dozen cookies. You then spoon the cookies, one dozen at a time, onto a cookie tray. These activities take 6 minutes for the washing and mixing steps, regardless of how many cookies are being made in the batch. That is, to mix enough dough and ingredients for three dozen cookies takes the same 6 minutes as for one dozen cookies. However, spooning the cookies onto the tray takes 2 minutes per tray. The next step, performed by your roommate, is to put the cookies in the oven and set the thermostat and timer, which in total takes about 1 minute. The cookies bake for the next 9 minutes. So total baking time is 10 minutes, during the first minute of which your roommate is busy setting the oven. Because the oven only holds one tray, a second dozen takes an additional 10 minutes to bake. Your roommate also performs the last steps of the process by first removing the cookies from the oven and putting them aside to cool for 5 minutes, then carefully packing them in a box and accepting payment. Removing the cookies from the oven takes a negligible amount of time, but it must be done promptly. It takes 2 minutes to pack each dozen and about 1 minute to accept payment for the order. This is the process you plan to use to produce cookies by the dozen at Kristen's Cookie Company. As experienced bakers know, a few simplifications were made in describing the actual cookie production process. For example, the first batch of cookies for the night requires preheating the oven. However, such complexities will be put aside for now. Begin your analysis by developing a process flow diagram of the cookie-making process.