In: Other
An automated car wash serves customers with the following serial process: pre-treat, wash, rinse, wax, hand dry. Each of these steps is performed by a dedicated machine except for the hand dry step, which is performed manually on each car by one of 4 workers. The steps of the process have the following processing times
Pre-treat: 5 minute per car
Wash: 3 minutes per car
Rinse: 1 minutes per car
Wax: 4 minutes per car
Hand dry: 12 minutes per car
a. If the car wash has a demand of 15 cars per hour, what is the flow rate of the process? (Do not round intermediate calculations. Round your answer to 2 decimal places)
b. If the car wash has a demand of 15 cars per hour, what is the utilization of the machine that performs the Wax process? (Round to nearest integer)
a. The capacities of each step is
Pre-treat : 60/5 = 12 per hour
Wash = 60/3 = 20 per hour
Rinse = 60/1 = 60 per hour
Wax = 60/4 = 15 per hour
hand Dry = 60 * 4/ 12 = 20 per hour (* 4 as there are 4 workers)
The bottleneck is Pre treat which is 12 per hour. as demand is higher than that the flow rate will be 12 cars per hour.
b. The wax process is limited by the bottleneck which is Pre-treat @12 cars per hour.
So utilization of Wax machine will be (4 * 12 )/ 60 = 80%