In: Operations Management
QUESTION 1
Use the following scenario and data for all questions
An auto service center provides two types of services, Tire
Replacement (T) and Oil Change (O). About 30% of the customers are
for Tire Replacement and the other 70% are for Oil Change. All
customers are serviced on a first come first served basis. During
regular hours, customers arrive at the service center according to
the probability distribution in the following table
Two technicians are working at the service center and both of them
are skillful enough for both Tire Replacement and Oil Change. Once
finishing the job for a customer, a technician will take care of
the next customer waiting in line. When both technicians are idle,
the one who finished the last job earlier will take care of the
next incoming customer. The times taken by the two jobs by any of
the technicians follow the probability distributions in the
following tables. You are required to simulate the operations of
the auto service center for 15 customers.
Before answering the following questions, you may use the following
tables to determine the cumulative probability distributions and
assign random number intervals for customer arrivals, customer
service types, and time needed for both types of services.
You may also simulate the operations of this auto service center
for the 15 customers using the random numbers given in the
following table. The “Start Time” is the time point when the job
for the customer starts and the “Finish Time" is the time point
when the job for the customer finishes.
For customer arrivals, the random number interval assigned to the
Time between Arrivals of 5 minutes is
0.0000-0.1499 |
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0.1500-0.3999 |
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0.4000-0.7999 |
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0.8000-0.9999 |
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None of the above |
1 points
QUESTION 2
For customer arrivals, the random number interval assigned to the Time between Arrivals of 15 minutes is
0.0000-0.1499 |
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0.1500-0.3999 |
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0.4000-0.7999 |
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0.8000-0.9999 |
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None of the above |
1 points
QUESTION 3
For the Customer Service Type, the random number interval assigned to Tire Replacement is
0.0000-0.6999 |
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0.0000-0.2999 |
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0.2999-0.9999 |
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0.3000-0.9999 |
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None of the above |
1 points
QUESTION 4
For the Customer Service Type, the random number interval assigned to Oil Change is
0.0000-0.6999 |
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0.0000-0.2999 |
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0.2999-0.9999 |
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0.3000-0.9999 |
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None of the above |
1 points
QUESTION 5
For the Tire Replacement, the random number interval assigned to Service Time 25 minutes is
0.0000-0.1999 |
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0.2000-0.4499 |
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0.4500-0.8499 |
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0.8500-0.9999 |
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None of the above |
1 points
QUESTION 6
For the Tire Replacement, the random number interval assigned to Service Time 35 minutes is
0.0000-0.1999 |
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0.2000-0.4499 |
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0.4500-0.8499 |
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0.8500-0.9999 |
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None of the above |
1 points
QUESTION 7
For the Oil Change, the random number interval assigned to the Service Time 15 minutes is
0.0000-0.2999 |
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0.3000-0.6999 |
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0.7000-0.8999 |
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0.9000-0.9999 |
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None of the above |
From the information
Customer arrival :
Time between arrivals | Probability | Cumultive Probability | Random number interval |
1 | 0.05 | 0.05 | 0.0000-0.0499 |
2 | 0.15 | 0.2 | 0.0500-0.1999 |
3 | 0.2 | 0.4 | 0.2000-0.3999 |
4 | 0.4 | 0.8 | 0.4000-0.7999 |
5 | 0.2 | 1 | 0.8000-0.9999 |
From the table
The random number interval assigned for the time between arrival of 2 minutes is 0.0500-0.1999.
Correct answer: 0.0500-0.1999.
From the table
The random number interval assigned for the time between arrival of 5 minutes is 0.8000-0.9999.
Correct answer: 0.8000-0.9999
Pump 1: (Self service).
Service Time (in minutes) | Probability | Cumulative Probability | Random number interval |
4 | 0.15 | 0.15 | 0.0000-0.1499 |
5 | 0.25 | 0.4 | 0.1500-0.3999 |
6 | 0.4 | 0.8 | 0.4000-0.7999 |
7 | 0.2 | 1 | 0.8000-0.9999 |
From the above table the for self service pump random number interval assigned to service time of 4 minutes is 0.0000-0.1499
Correct answer : 0.0000-0.1499
From the above table the for self service pump random number interval assigned to service time of 6 minutes is 0.4000-0.7999
Correct answer :0.4000-0.7999.
Pump 2: (full service).
Service Time (in minutes) | Probability | Cumulative Probability | Random number interval |
5 | 0.20 | 0.20 | 0.0000-0.1999 |
6 | 0.30 | 0.50 | 0.2000-0.4999 |
7 | 0.40 | 0.90 | 0.5000-0.8999 |
8 | 0.10 | 1 | 0.9000-0.9999 |
From the above table the for full service pump random number interval assigned to service time of 5 minutes is 0.0000-0.1999
Correct answer : 0.0000-0.1999
From the above table the for full service pump random number interval assigned to service time of 8 minutes is 0.9000-0.9999
Correct answer : 0.9000-0.9999.