Comfy Shoes Inc. builds shoes tailored to meet each individual customer’s needs.
ID: 3294318 • Letter: C
Question
Comfy Shoes Inc. builds shoes tailored to meet each individual customer’s needs. Customers who visit the downtown offices of Comfy Shoes in the city can choose one or more of the following four custom-tailoring services. Customers receive their shoes in the mail within a week of their initial visit.
b. If the number of customers increases to 115 per day and nothing else changes, how many customers a day will not be served within the 10-hour day? What would be potential responses to this increased demand?
Comfy Shoes Inc. builds shoes tailored to meet each individual customer's needs. Customers who visit the downtown offices of Comfy Shoes in the city can choose one or more of the following four custom-tailoring services. Customers receive their shoes in the mail within a week of their initial visit. Service Description Time Resource used A. Walking Basics Take measurements for basic walking 12 2 identical attendants, working in parallel B. Walking Plus 6 min. Choose specific design (e.g. material, color selection) 1 attendant C. Running Basics Take measurements for tailor-made running shoes 5 min 1 attendant D. RunningAConsult physical therapist and obtain 20 min. 1 attendant precise needs for running shoes. Also choose specific desig The company offers the following packages to their customers 1. Package 1: Includes only Walking Basics (Service A) 2. Package 2: Includes Walking Basics and Walking Plus (Services A and B) 3. Package 3: Walking Basics, Walking Plus and Running Basics (Services A, B and C) 4. Package 4: All four services (A, B, C, and D) Customers of Comfy Shoes visit the store at a constant rate (you can ignore any effects of variability) of 40 customers per day. Of these customers, 45% or 18 customers buy Package 1,10% buy Package 2, 20% buy Package 3 and 25% buy Package 4. The mix does not change over the course of the day. The store operates 10 hours a day a. In order to know how busy each attendant is and determine which resource/service will have the highest utilization, calculate the implied utilization of each resource in the table below; use empty space in the right-side of the table to show any intermediate calculations Resource Implied Utilization Calculations Comments Service A. Walking Basics B. Walking Plus C. Running Basics Resource C is clearly not the bottleneck as it handles lower demand and is faster per customer than Walking Plus Not Required D. Running Bottleneck Resource / Service =Explanation / Answer
Solution
Part (a)
Package
No of customers
Total time taken to service given no of customers (minutes)
A (12 min)
B (6 min)
C (5 min)
D (20 min)
1
18
18 x 12
-
-
-
2
4
4 x 12
4 x 6
-
-
3
8
8 x 12
8 x 6
8 x 5
-
4
10
10 x 12
10 x 6
10 x 5
10 x 20
Total
40
40 x 12 = 480
22 x 6 = 132
18 x 5 = 90
10 x 20 = 200
Utilization %
-
480/600 = 80%
132/600 = 22%
90/600 = 15%
200/600 = 33.33%
As such, no service is a bottleneck, assuming attendants for all services work for 10 hours (600 minutes.)
Part (b)
Identical calculations for 115 customers would give the following utilization percentages:
Package 1: (115 x 12)/600 = 230% clearly a bottleneck
Package 2: (63.25 x 6)/600 = 63.25% clearly not a bottleneck
Package 3: (51.75 x 5)/600 = 43.125% clearly not a bottleneck
Package 4: (28.75 x 20)/600 = 95.83% not, but pretty close, to a bottleneck.
At 100% utilization, only 50 customers taking A, either alone or in combination, can be serviced per day and hence 65 customers taking A, either alone or in combination will not get servicd.
Package
No of customers
Total time taken to service given no of customers (minutes)
A (12 min)
B (6 min)
C (5 min)
D (20 min)
1
18
18 x 12
-
-
-
2
4
4 x 12
4 x 6
-
-
3
8
8 x 12
8 x 6
8 x 5
-
4
10
10 x 12
10 x 6
10 x 5
10 x 20
Total
40
40 x 12 = 480
22 x 6 = 132
18 x 5 = 90
10 x 20 = 200
Utilization %
-
480/600 = 80%
132/600 = 22%
90/600 = 15%
200/600 = 33.33%