Jeff and his roommate are in the cake baking business. When they receive an order over the internet, Jeff prepares a bowl and mixes cake batter according to the order (takes 6 minutes). He then pours the batter into a baking pan that holds 1 cake (2 minutes). His roommate then puts the cake pan in the oven and sets a timer (1 minute). Cakes bake in the oven for 9 minutes and then are cooled outside the oven on a rack for 5 minutes. Finally the roommate takes 2 minutes to box the cake and then collects payment from the arriving customer (1 minute).

Expect that each order is composed of a two tier cake (2 cakes). Although the mixing bowl can hold batter for two cakes at one time, assume the oven can only hold one cake pan at a time. As mentioned above, pouring batter into each pan takes 2 minutes, and both cakes must be cooled before boxing the cake for the customer.

 

a. Determine theoretical flow time from the order thru payment. Assume no waiting over the entire process.        

           [a] minutes

Now consider the effect on flow time given the following alternatives:

b. Buy a second oven that can bake one cake pan (plus existing oven cooking 1 cake pan).

          [b] minutes

c. Replace oven with one that can hold two cake pans at the same time (still 9 min bake).

          [c] minutes

d. Replace oven with a faster convection oven that can bake one cake pan in 6 minutes (instead of 9).

          [d] minutes