3. Bills car wash offers two types of washes. Standard and Deluxe. The process flow for both types of customers is shown in the following diagram below. Both wash types are first processed through steps A1 and A2. The standard wash then goes through steps A3 & A4 while the deluxe is processed through steps A5, A6 and A7. Both finish at the drying station A8. The numbers in parentheses indicate the minutes it takes for the activity to process a customer.

Stage A (5) Stage B (3) Stage C (6) Stage D (4) Stage E (4)

a. What step is the bottleneck for the standard car wash process?

b. What step is the bottleneck for the deluxe car wash process?

c. What is the capacity (measured by the customers served per hour) of bills Car wash to process standard and deluxe customers? Assume no customers are waiting at step A1, A2 or A8.

d. If 60% of the customers order the Standard and 40% order the deluxe wash, what is the average capacity of the car wash in customers per hour.

e. Where would expect standard wash customers to experience waiting lines, assuming that 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?