Operations Management (Practice Exam)
Time allowed for exam: 4 hours
运营管理代考 IceSculpt Industries makes custom ice sculptures, serving pieces and flavored ice cubes for drinks for caterers and party planners.
INSTRUCTIONS FOR STUDENTS: 运营管理代考
- This is an open book exam. You may refer to your notes, course text and other materials to answer the questions.
- You may use a calculator.
- This is an individual exam. You may not discuss its content or solutions with anyone. Suspected collusion will be investigated in line with the School’s Student Disciplinary Policy.
- Save your solution file with the file name ‘[Course code – your LBS Number]’. Do not include your name anywhere in the document.
- You should submit the file in Word or PDF format. 运营管理代考
- Please make sure that the correct solution file has been uploaded by downloading and checking it, once it has been uploaded. Wrong submission may result in failing the exam.
- Show your working. Partial credit is given to answers that are numerically incorrect but that show correct understanding of the solution method.
- If the question is not clear, state your assumptions and if they are reasonable you will be given credit.
- A total of 60points are available for this exam. Allocate your time optimally.
- Good luck!
For all the questions below, if a box is provided, please put your numeric answer in the box below the question, and show all of your working and explain your reasoning below the box unless otherwise noted. Each question is worth 5 points.
IceSculpt Industries (Q1-Q3) 运营管理代考
IceSculpt Industries makes custom ice sculptures, serving pieces and flavored ice cubes for drinks for caterers and party planners. They receive deliveries of two kinds of ice over the course of the day: Tasty Ice and Pretty Ice. Each block weighs twenty pounds. Tasty Ice is delivered at a rate of 1,000 blocks/hour, with deliveries arrives from 9am to 2pm. Pretty Ice is delivered at a rate 2,000 blocks/hour, with deliveries arriving from 8am to 1pm. You can treat the delivery rate of ice as continuous. Any ice that can not be processed immediately is kept in a walk-in cooler. The following is the process flow diagram, in which the capacity rates at each step are also shown.
(Q1) What is the implied utilization of each step at 11am? Show answers only. No need to show calculations.
| Receiving | Flavouring | Basic Sculpting | Fine Sculpting | Prepping for Delivery |
(Q2) What is the peak inventory of Tasty Ice? At what time of the day does the Tasty Ice cooler become empty? Based on your diagram, what is the peak inventory of Pretty Ice? At what time of the day does the Pretty Ice cooler become empty? 运营管理代考
| What is the peak inventory of Tasty Ice | |
| At what time of the day does Tasty Ice cooler become empty? | |
| What is the peak inventory of Pretty Ice | |
| At what time of the day does Pretty Ice cooler become empty? |
(Q3) IceSculpt has an hourly cooling cost of $0.04/hundred pounds of ice kept in the coolers. What is IceSculpts total daily cooling cost?
Insurance Call Centre (Q4-Q5) 运营管理代考
An auto insurance company office in San Francisco, California has a call centre with six operators. The operators have been divided into three groups of two each, with each pair responsible for calls originating from a different California county. Each incoming call is handled by one operator. Calls from each county arrive at a rate of 16 per hour. Each call centre operator takes on average 6 minutes to handle a call. Assume exponential inter-arrival times and exponential service times.
(Q4) What is the average length of queue of calls waiting to be served by an operator in this setup?
(Q5) What would the average length of queue of calls be if they decided that an incoming call from any county could be served by an operator in any of the three groups of two? Explain qualitatively why you would expect to see the increase or reduction in length of queue.
Hotel California (Q6-Q7)
Hotel California is a luxury hotel which has just got a new manager, Rocky. Given its location and quality, the hotel always had enough people making advance reservations to fill up all the rooms available. The hotel charges $200 per room per night for reservations made in advance. Rocky had heard about revenue management in one of the seminars and decided to implement some of those techniques in his current job. He implemented a policy of keeping some rooms free for last minute requests and charges these requests $300 per room per night. Currently, the hotel keeps 3 rooms free to accommodate last minute requests. After a month of implementing this policy, the hotel management reviewed their records and found the following. 运营管理代考
| Number of rooms Requested at the Last Minute | Frequency
(days) |
Probability | Cumulative Probability |
| 0 | 5 | 0.167 | 0.167 |
| 1 | 3 | 0.1 | 0.267 |
| 2 | 6 运营管理代考 | 0.2 | 0.467 |
| 3 | 8 | 0.267 | 0.733 |
| 4 | 4 | 0.133 | 0.867 |
| 5 | 1 | 0.033 | 0.9 |
| 6 | 1 | 0.033 | 0.933 |
| 7 | 2 | 0.067 | 1 |
| Total: 30 |
(Q6) Is Hotel California maximizing its expected profit by keeping 3 rooms available for last minute requests?
(Q7) On a completely different season, Rocky observed that many of the booked rooms had no-shows. In order to compensate for that, Rocky decided to overbook customers. If a customer with a reservation arrives and the hotel is already full, Rocky needs to pay them an additional compensation of $400 along with a refund of their reservation. However, if customers don’t show up and the hotel room goes empty and the hotel loses revenue of $200 per room. What is the newsvendor critical ratio for no shows?
Furniture Manufacture (Q8-Q9) 运营管理代考
A furniture factory uses statistical process control to manage quality of its products. For its “comfy” sofa line, the target width of the sofa is 60 inches, with a tolerance of +/- 0.2 inches around this target. The mean width of the comfy sofa output is on target. Comfy sofa widths are normally distributed with a standard deviation of 0.08 inches.
(Q8) Is the process for making comfy sofas capable? Evaluate based on its capability ratio. 运营管理代考
Enter your answers in the box below and show your work in the space provided.
| Capability ratio and yes/no the process is capable |
(Q9) What would you recommend to the plant manager regarding the quality of output from the comfy sofas production line?
Abuelito’s Burritos (Q10-Q12)
Abuelito’s sells fresh Mexican food to the local community. You may assume that each customer orders 1 burrito and 1 drink, the restaurant has plenty of space for waiting, and the buffers between any two successive steps are sufficiently large. There is one employee working at each step. The process flow for filling a burrito order and the time required for each step is shown below:
Management is considering introducing a super-sized Burrito Gordo, which would have triple the fillings of the regular burrito stuffed into an extra-large tortilla. The Burrito Gordo is priced at $8.10, and have a contribution margin of $3.60. The regular burrito is priced at $4.25, and have a contribution margin of $2.50. Making a Burrito Gordo is the same as a regular burrito, except that the Fill Tortilla step takes 90 seconds instead of 50 seconds. Management estimates that 25% of customers would purchase a Burrito Gordo instead of a regular burrito.
Management is considering whether capacity, revenue, and profit will increase, decrease, or remain unchanged. Please logically justify your answers with supporting calculations. 运营管理代考
(Q10) If Burrito Gordo is added to the menu and no other process changes are made (i.e., no addition of staff members or equipment), what will happen to Abuelito’s average burrito production capacity (number of burritos per hour)?
(Q11) What will happen to Abuelito’s maximum expected revenue per hour?
(Q12) What will happen to Abuelito’s maximum expected contribution margin per hour?
