Question

QUESTION 1

1. CC Car Wash specializes in car cleaning services. The services offered by the company, the exact service time, and the resources needed for each of them are described in the table following:

   Service	Description	Processing Time	Resource
   A. Wash	Exterior car washing and drying	10 minutes	1 automated washing machine
   B. Wax	Exterior car waxing	15 minutes	1 automated waxing machine
   C. Wheel Cleaning	Detailed cleaning of all wheels	16 minutes	1 employee
   D. Interior Cleaning	Detailed cleaning inside the car	20 minutes	1 employee

   The company offers the following packages to their customers:

   • Package 1: Includes only car wash (service A).

   • Package 2: Includes car wash and waxing (services A and B).

   • Package 3: Car wash, waxing, and wheel cleaning (services A, B, and C).

   • Package 4: All four services (A, B, C, and D).

   Customers of CC Car Wash visit the station at a constant rate (you can ignore any effects of variability) of 50 customers per day. Of these customers, 30 percent buy Package 1, 30 percent buy Package 2, 15 percent buy Package 3, and 25 percent buy Package 4. The mix does not change over the course of the day. The store operates 10 hours a day.

d. What resource has the highest utilization rate? Input 1 for washing machine, input 2 for waxing machine, input 3 for employee at C, input 4 for employee at D.

Your answer is .

Answer 1

d)

Number of customers who buy package 1 = 50*0.30= 15

Number of customers who buy package 2 = 50*0.30= 15

Number of customers who buy package 3 = 50*0.15= 7.5

Number of customers who buy package 4 = 50*0.25= 12.5

Load of Service A = Flow rate of customers who buy package 1,2,3,4, which include service A * processing time of service A =  (15+15+7.5+12.5)*10 = 500 minutes per day

Load of Service B = Flow rate of customers who buy package 2,3,4, which include service B * processing time of service B = (15+7.5+12.5)*15 = 525 minutes per day

Load of Service C = Flow rate of customers who buy package 3,4, which include service C * processing time of service C = (7.5+12.5)*16 = 320 minutes per day

Load of Service D = Flow rate of customers who buy package 4, which include service D * processing time of service D = (12.5)*20 = 250 minutes per day

Capacity of each resource = 10 hours = 600 minutes per day

Utilization of washing machine at A = Load / Capacity = 500/600 = 83.3 %

Utilization of waxing machine at B = Load / Capacity = 525/600 = 87.5 %

Utilization of employee at C = Load / Capacity = 320/600 = 53.3 %

Utilization of employee at D = Load / Capacity = 250/600 = 41.7 %

Utilization of waxing machine (B) is the highest (87.5%)

ANSWER: 2 (for waxing machine)