a. Step A4 is the bottleneck for th

a. Step A4 is the bottleneck for the Standard car wash process, and Step A6 is the bottleneck for the Deluxe car wash process, because these steps take the longest time in the flow.b. The capacity for Standard washes is four customers per hour because the bottleneck Step A4 can process one customer every 15 minutes (60/15). The capacity for Deluxe car washes is three customers per hour (60/20). These capacities are derived by translating the “minutes per customer” of each bottleneck activity to “customers per hour.”c. The average capacity of the car wash is 10.60 * 42 + 10.40 * 32 = 3.6 customers per hour.d. Standard wash customers would wait before Steps A1, A2, A3, and A4 because the activities that immediately precede them have a higher rate of output (i.e., smaller processing times). Deluxe wash customers would experience a wait in front of Steps A1, A2, and A6 for the same reasons. A1 is included for both types of washes because the arrival rate of customers could always exceed the capacity of A1.