Which step is the bottleneck for the Standard car wash process? For the Deluxe car wash process?

                                                                          i.      For the Standard Wash, the bottleneck is step A4

                                                                        ii.      For the Deluxe Car wash it is Step A6

b.                  What is the capacity (measured as customers served per hour) for Bill’s Car Wash to process a Standard and Deluxe customers? Assume no customers waiting at  step A1, A2 or A8.

                                                                          i.      The speed of movement could be as fast for you line, as the speed of your bottleneck. So, if standard time to wait is 15 minutes, then 4 cars can be given standard wash on per hour basis. However, when deluxe wash is done, then it will take 20 minutes for the bottleneck, so only 3 cars can be washed on per hour basis.

c.                   If 60 percent of the customers are Standard, and 40 percent are Deluxe, what is the average capacity of the car wash per hour?

                                                                          i.      7*.6 = 4.2

                                                                        ii.      7*.4 =2.8

                                                                      iii.      (4.2+2.8)/2 = 3.5 cars average per hour

d.                  Where would you expect Standard wash customers to experience waiting lines, assuming the new customers are always entering the shop and that no Deluxe customers are in the shop? Where would the Deluxe customers have to wait, assuming no Standard customers?

assuming no deluxe customers, the standard customers would have to wait during step A4.  If there was no standard customers , the Deluxe customers would have to wait at step A6