Over the past few years, Isaac has noticed that he gets inte…

Questions

Over the pаst few yeаrs, Isаac has nоticed that he gets intense headaches and abdоminal pain mоst often on the days leading up to exams in his classes. Which of the following is his physician most likely to say regarding the cause of these symptoms?

Multiple Chоice Questiоns: Circle the аnswer (оnly one) you feel is best for the following multiple choice questions.  9. [1] Consider а firm thаt regularly receives full truckload deliveries. Suppose they double the number of SKU's carried on each truck by halving the number of units hauled of each SKU. Holding the number of truck deliveries per unit of time fixed, the average cycle-stock  (a) doubles (b)stays the same (c) halves (d) multiplies by (e) divides by .   10. [1] The optimal batch size in a production process (according to the EOQ model) does NOT depend on: (a) The variability of downstream demand. (b) The fixed order cost. (c) The opportunity cost of capital. (d) It depends on (a), (b) and (c).    11. [1] Which one of the well studied problems in Operations Research can be leveraged for solving delivery routing problem of Peapod? (a) Chinese Postman Problem. (b) Traveling Salesman Problem. (c) Network Flow Problem. (d) Cutting Stock Problem.   12. [1] For a company such as Webvan, building a warehouse is less attractive when: (a) demand is higher. (b) delivery densities are higher. (c) number of deliveries per route is fewer. (d) All of the above.    13. [1] Which of the following statements is correct? (a) doubling expected demand doubles the optimal order quantity. (b) doubling the leadtime for delivery doubles the optimal safety stock. (c) doubling the leadtime for delivery doubles the expected leadtime demand. (d) All of the above.    14. [1] In Jungle Books, by centralizing the inventory, they can (a) Multiply cycle stock by a factor of . (b) Multiply safety stock by a factor of . (c) Multiply safety stock by a factor of . (d) Both a and b. (e) Both a and c.   15. [1] A firm manages a single durable product by placing regular orders from a supplier with fixed shipping costs of $64 per shipment. The firm incurs direct holding costs of $4 per unit per year and sees an average monthly demand of 24 units. When deciding its order quantity optimally, it incurs annual shipping costs of (a) $192. (b) $96. (c) $484. (d) $288. (e) $384.   16. [1] Two workers are working in parallel to process a large backlog of orders.  An order must either be processed by worker 1 or by worker 2. Worker 1 can process an order in minutes, worker 2 can process an order in minutes, and each worker can work on at most one order at a time. Given the system is run to maximize capacity, which of the following expressions represents the average cycle time of an order? Assume there is no variability in the system. (a) (b) (c) (d) (e)   17. [1] In the newsvendor model (a) expected sales can be less than expected demand. (b) the quantity purchased is a random variable. (c) there are multiple opportunities to order. (d) it is required to have a continuous distribution of demand.   18 [1] Suppose a SKU of dry pasta at Barilla, a leading pasta producer, is managed according to a (Q,R) inventory policy. Its distributors place orders with Barilla, who in turn distribute Barilla products to various retailers. The fact that orders from its distributors are highly volatile impacts (a) deciding the optimal order quantity. (b) deciding the optimal re-order point. (c) both (a) and (b). (d) neither (a) nor (b).   19. [1] Suppose that a doctor's utilization is 85%. The interarrival times of patients are exponentially distributed. The treatment times of the patients are also exponentially distributed. How many patients are in the doctor's waiting room, on average (rounded to the nearest integer)? (a) 1 patient. (b) 5 patients. (c) 9 patients. (d) there is not enough information to determine the average number of patients.   Consider the following system for Questions 20 and 21. All the jobs should go through servers A, B, and C. The processing time of one job is 1, 2, and 3 minutes on servers A, B, and C respectively. Servers A and B require a set up of 10 minutes and 5 minutes before processing respectively. There is no setup required for server C.   20. [1] Assume that the jobs are processed in batch sizes of 10. Which server is the bottleneck in the system above? (a) A (b) B (c) C (d) Every server is a bottleneck.   21. [1] Next, assume that jobs are processed in batches of size 5. Which server is the bottleneck in the system? (a) A (b) B (c) C (d) Every server is a bottleneck. (e) There is no bottleneck.  

The midterm exаm is here.    If yоu hаve trоuble viewing the midterm exаm in pdf fоrmat, I am providing the instructions and the questions in text format below.    Instructions: Sign the Booth honor code in the Midterm Exam Submission quiz. You can only consult your one page cheat sheet during the exam.  Maximum total points you can get in this exam is 25. I am providing you with 30 points worth of questions. Thus, you can still achieve a perfect score, even if you leave some questions unanswered, or answer them incorrectly. Points for each question are shown in brackets. It is YOUR responsibility to ensure that you have 30 points worth of questions in your exam. Exam duration = 2.5 hours. For problems 1–5, if a question requires analysis you must show your work for each question in order to receive credit. Partial credit is awarded for partial success on each attempted question. Please be clear in your work. It is hard to grade a sea of numbers on each page. State carefully what you know and what formulas you are going to use.   Questions:  [4 points] Consider the following process flow diagram, where each step is staffed by a single server. All jobs take exactly the time indicated (no variability). Suppose all jobs must flow through the top path AND the bottom path before they can move to the final step, i.e. both paths must be completed to move on. The jobs can be temporarily stored in the queue before moving to the next step if there need be. (a) [1] Compute the capacity of the system (in jobs per minute). (b) [1] Compute the average cycle time of a job (in minutes).   Suppose all jobs must flow through either the top path OR the bottom path before moving to the final step. (c) [1] Compute the capacity of the system (in jobs per minute). (d) [1] Assuming that there is a 50/50 split of jobs between the top and bottom paths, compute the average cycle time of a job (in minutes).     [5 points] BoothCater, a small catering business, provides custom meal services for local events and parties, such as the lunch for workshops at Booth School of Business. BoothCater can now receive orders through different channels such as phone calls, walk-ins, and online orders. In order to guarantee prompt order fulfillment and customer satisfaction, the owner has established a standard process to handle orders at frequent intervals during the day. Following this, each order has two steps to process: the first is to prepare the meals, and the second is to package them according to the delivery or pickup option chosen by the customers. These steps are always done in this order. Currently, there is only one staff member at each stage: the kitchen staff Alex is responsible for preparing the meals, and the packaging staff Jane packages the meals. Alex can prepare an order in 6 minutes on average, and Jane can package an order in 5 minutes on average. They work independently to complete their tasks. (a) [1] What is the capacity of the catering business (in orders per hour)? (b) [1] It turns out that the processing times of both Alex and Jane exhibit variability and are distributed exponentially. On average, orders arrive at a rate of 6 per hour (assume that the inter-arrival times were exponentially distributed). How long does an order spend in the catering process on average? [Hint: You can use Burke’s theorem!] (c) [1] What is the long-run average number of orders in the catering process, given the current set up of inter-arrival and service times?   Later in the quarter, as the catering business becomes busier, the owner decides to hire a second kitchen staff member, Tom, to assist with meal preparation. Tom is less experienced than Alex and takes an average of 8 minutes to prepare an order. For the remainder of the question, assume that there is no variability in the processing time of all three staff members, Alex and Tom work independently on meal preparation, and only Jane handles packaging. (d) [1] Draw the process flow diagram of this operation. At each stage of the operation, state the resource (Alex, Tom or Jane) that is used and note the processing times. (e) [1] What is the capacity of the catering business when Alex, Tom and Jane are all present (in orders per hour)?     [4] After implementing the new service system in the catering business, the Booth Cater owner noticed that the time it takes for each order to be fulfilled can vary depending on factors such as the type of order and the workload of the kitchen staff. The owner recorded the time between successive orders and the time it takes for each order to be fulfilled in the following table. (Note: For this question, assume the orders are fulfilled one at a time.) The owner wants to evaluate the performance of the new system and answer the following questions: (a) [1] Compute the time T at which the fifth order is fulfilled, starting from time 0 (in minutes). (b) [1] How long (in minutes) did five orders spend in the system on average? (c) [1] On average, how many orders are in the system at any given time (take the average from time 0 to time T computed in part (a))? (d) [1] Compute the total time spent by all five orders in the waiting area (in minutes). [Hint: Consider the time spent waiting in the system without being processed.]     [4 points] Disneyland is one of the most popular theme parks in the world, attracting visitors from all over the globe. In order to offer an exclusive experience, Disneyland has started to offer ”Early Entry” tickets to a limited number of visitors. These tickets allow guests to enter the park one hour before the official opening time of 9:00 am. In the proposed operations plan, the number of guests with Early Entry tickets is limited to 500 per hour between 8:00-9:00 am. At 9:00 am, guests with regular tickets start arriving at a rate of 1300 people per hour and they keep arriving with this rate until the admission is closed at 4:00 pm. Meanwhile, guests start leaving the park at a rate of 1000 people per hour at 1:00 pm, independently of when they arrived. To ensure a pleasant experience for all guests, the maximum number of visitors allowed in the park at any given time should be 6000. (a) [1] Using the axes below plot the inventory buildup diagram. [Hint: The Disneyland stays open until inventory drops back to 0.] (b) [1] In the proposed operations plan, does the inventory of visitors ever exceed the limit of 6000? What is the highest inventory reached each day? (c) [1] For how many hours a day does the Disneyland have visitors? (d) [1] For how many hours, if at all, does the inventory go above the limit of 6000?     [4 points] The candy store at Disneyland sells a wide range of Disney-inspired candies. The most popular candies among visitors are the Mickey Mouse-shaped gummies and the princess lollipops. Magical Candy Co. provides gummies and lollipops for the candy store. There are three main steps for candy production. The first step is to prepare the candy base by heating and mixing sugar, corn syrup, and water in a large kettle. It takes 1 hour to produce 30 lbs of candy base. The second step is to add flavoring and color to the candy base and then shape it into the desired candy form. Machine 1 is used to shape the gummies, and it takes 6 minutes to shape 1 lb of gummies. Machine 2 is used to shape the caramel lollipops, and it takes 15 minutes to shape 1 lb of lollipop. The third step is to add decorations to the candy. This step is done manually by a team of candy decorators, and it takes 12 minutes to decorate 1 lb of gummies and 10 minutes to decorate 1 lb of lollipops. One lb of gummies is sold at $25, and one lb of princess lollipop is sold at $40 to the candystore. Magical Candy Co. is interested in maximizing its revenues from sales to the candy store in Disneyland. Assume that the candy base can be produced 6 hours per day, and the other machines can be operated 11 hours per day with no set-up time. Additionally, the candy decorators can work at most 9 hours per day. Let G indicate how many lbs of gummies are produced in the workshop in one day and let L indicate how many lbs of princess lollipop are produced in one day. (a) [1] Clearly define your objective function. (b) [3] Clearly list all constraints.     Multiple Choice Questions: Determine the single best answer for each of the following multiple-choice questions.    [1] Which of the element did Jame Smith, the CEO of Mobismile bikesharing, fail to properly consider when introducing the subscription plan? (a) New customers. (b) Bike damage rate. (c) Rebalancing cost. (d) Cycle time of bike repairing. (e) All of the above.     [1] In the presence of uncertainty, the system cycle time: (a) is the same as when processing and inter-arrival times are deterministic. (b) is always the same in two systems with the same system capacity and system variability. (c) is determined by the length of the same path through the system regardless of system throughput. (d) None of the above.     [1] Suppose that customers arrive at a single server at a rate of 1/3 customers per minute. The capacity of the server is 1/4 customers per minute. Both the service time and the interarrival time are assumed to be exponential. Suppose further that the system is initially empty. As the system unfolds, its inventory (in process and waiting) will (a) reach a long-run average of 3/4 customers (b) reach a long-run average of 4/3 customers (c) stay in the system an average of 12 minutes (d) grow unboundedly in the long-run (e) None of the above     [1] Which of the following statements regarding the capacity of a process is true: (a) Capacity depends only on the inputs of the system. (b) The capacity of an operation is determined by its bottleneck(s). (c) The capacity of the system is inverse of the system cycle time. (d) Both (b) and (c). (e) All of the statements are true.     [1] Customers arriving at a hotel have an average stay of 2 weeks. If number of customers who arrive on a given day is 14 on average, what is the number of customers staying at the hotel on average? (a) 98 (b) 196 (c) 7 (d) 28     [1] Consider callers waiting on hold at a call center. We plot the number in the queue over time. That is, the horizontal axis represents time, t, and the vertical axis represents the number of callers on hold. The area under the curve would indicate (a) the total inventory of callers waiting at time t, INVq(t). (b) the total waiting time of all callers. (c) the maximum time a caller must wait. (d) the average waiting time of a caller, CTq.     [1] The average arrival rates of international and domestic fliers to an airport pub are respectively 10 per hour and 15 per hour. The average time spent in the pub for an international flier is 50% longer than that for a domestic flier. On average, what fraction of customers in the pub will be international fliers? (a) 50%. (b) 33.3%. (c) 66.6%. (d) 44.4%.       Consider the following process for the next two questions. Arriving orders are split into two jobs. One job is processed by the top path, the other is processed by the bottom path, and the jobs rejoin following processing. Each box in the diagram represents a single server and the times indicate average processing times, in minutes.     [1] Assume that there is variability in inter-arrival times and processing times, and that throughput is very close to the system capacity. Queues are allowed to form in front of each server. (a) A, B, and C are capacity bottlenecks, and they are on the critical path. (b) E is a capacity bottleneck. A, B, and C are on the critical path. (c) A, B, and C are capacity bottlenecks, and E is on the critical path. (d) E is a capacity bottleneck, and it is on the critical path.     [1] If there is no variability in inter-arrival times and processing times and throughput is less than system capacity, then (a) A, B, and C are capacity bottlenecks, and they are on the critical path. (b) E is a capacity bottleneck. A, B, and C are on the critical path. (c) A, B, and C are capacity bottlenecks, and E is on the critical path. (d) E is a capacity bottleneck, and it is on the critical path.