MGO 302 Operations Management © NC Simpson 2015 MGO 302: Production and Operations Management SKELETON NOTES: Fall 2015 What is that stuff across the bottom of each page??? On the left: Occasional humbnails of PowerPoint slides and spreadsheets discussed in class, which you can download from the MGO302 Documents section of UBlearns… Note Page 1 Intro/Providing Goods and Services On the right: Thumbnails of “Keyword Slides” that can be downloaded for free from noteshaper.com Information that appears within ‘starbursts’ like this refer to the textbook Practical Operations Management MGO 302 Operations Management © NC Simpson 2015 OPERATIONS MANAGEMENT: WHERE DO WE FIT IN... Note Page 2 Intro/Providing Goods and Services More Detail: Pages 18-19; Scenario 1b on page 19 MGO 302 Operations Management © NC Simpson 2015 An Operation (Any Operation) What has productivity got to do with this view of a production system? Sustainability? Note Page 3 Intro/Providing Goods and Services More Detail: Pages 2-7 MGO 302 Operations Management Note Page 4 Intro/Providing Goods and Services © NC Simpson 2015 More Detail: Pages 14-17; Scenario 1a on page 17 MGO 302 Operations Management © NC Simpson 2015 CLASSIFYING PRODUCTS: Goods vs. Services Note Page 5 Intro/Providing Goods and Services More Detail: Pages 8-10 MGO 302 Operations Management © NC Simpson 2015 CLASSIFYING PRODUCTS: Standardized vs. Customized Note Page 6 Intro/Providing Goods and Services More Detail: Pages 35-39 MGO 302 Operations Management © NC Simpson 2015 PRODUCT LIFE CYCLE Demand Time Note Page 7 Intro/Providing Goods and Services More Detail: Pages 39-41 MGO 302 Operations Management © NC Simpson 2015 MEASURING PRODUCTIVITY… Partial measure- Multi-factor measure- Total measure- Lanark Farms sells fresh strawberries, growing the fruit both in open fields and within long clear plastic hoop tents, known as its tunnel operation. Last year, Lanark’s 50 acres of open fields produced 25 tons of fresh strawberries, while the longer growing season under its 10-acre tunnel operation produced 20 tons. How productive is Lanark’s open-field operation? Is it more productive than Lanark’s tunnel operation? Note Page 8 Intro/Providing Goods and Services More Detail: Pages 41-45, including Scenarios 1, 2a and 2b starting on page 42 Similar Practice: End of Chapter Scenarios #21 and #22 MGO 302 Operations Management © NC Simpson 2015 One key to the productivity of Lanark’s tunnel operation is the higher air temperatures under the plastic tents, extending the length of the growing season but making the plants more vulnerable to disease. As a result, Lanark spends $225 per acre for preventative chemical treatments in its tunnel operation, whereas it spends only $20 per acre for its open fields. The tunnel operation costs $250 per acre to construct and maintain throughout the year. All Lanark’s strawberries require $125 per acre to plant and $600 per ton to harvest and pack. Now how productive is Lanark’s open field operation? Note Page 9 Intro/Providing Goods and Services MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON PROVIDING GOODS AND SERVICES: Video tutorials explaining each of these questions are available on UBlearns. 1. Systems which produce highly customized products typically: a) produce in relatively high volumes b) have relatively low costs per unit produced c) have invested a great deal of money in automation d) can produce the product relatively quickly e) use relatively high skilled workers 2. Which of the following is generally not a characteristic of a service operation? a) intangible output b) high customer contact c) high labor content d) stockpiling of output for future use e) low uniformity of output 3. A large corporation has twelve different divisions that operate as twelve business units. Two of its divisions each develop and launch a new product in data management, only to discover that their new products are competing with each other in the corporation’s largest market. This large corporation is best described as having a problem with what? a) core competency b) sub-contracting c) outsourcing d) goal alignment e) economies of scale 4. In an assembly operation at a furniture factory, six employees assembled an average of 450 standard dining chairs during a five day work week. Which of the following best describes the labor productivity of this operation? a) 450 chairs b) 90 chairs/day d) 20 chairs/worker-day c) 75 chairs/day e) 15 chairs/worker-day Similar to this: Chapter 2 Quick Start #14, #15, and #16 5. An operation has a 20 percent scrap rate. As a result, 56 pieces per hour are produced. What is the potential increase in labor productivity that could be achieved by eliminating the scrap? a) 20% b) 25% c) 75% d) 80% e) 100% Somewhat similar: Chapter 2 Scenario #21, part b Note Page 10 Intro/Providing Goods and Services MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON PROVIDING GOODS AND SERVICES, CONT’D: Consider the following five situations: construction of a luxury cruise ship, operation of casual dining restaurant, staging of a professional sports match, manufacturing a patented drug, and rescuing stranded animals from a flooded area. Now consider the following grid, which indicates five positions marked A, B, C, D and E. Each of these positions indicates differing levels of tangibility and operation types: Similar to this: Chapter 1 Scenario #19 Match each of the five operations to its most appropriate position on this grid, using each position only once. Please answer the following question, based on this exercise. 6. Which position on the grid best matches rescuing stranded animals from a flooded area? a) position A b) position B c) position C d) position D e) position E Note Page 11 Intro/Providing Goods and Services MGO 302 Operations Management © NC Simpson 2015 DEFINING QUALITY Remember that quality is an “attribute.” That means everything has quality. FIRST: The “Old” Definition QUALITY = NEXT: A “Newer” Definition (s) Note Page 12 Product Quality and Development More Detail: Pages 52-55 MGO 302 Operations Management © NC Simpson 2015 “TOTAL” QUALITY MANAGEMENT A FEW ELEMENTS TQM ELEMENT: Everyone is a QC Inspector. Tools? TQM ELEMENT: The customer defines quality. Tools? TQM ELEMENT: Fix problems at their source. Tools? TQM ELEMENT: Involve suppliers. Consider distribution, installation, and use. TQM ELEMENT: The commitment of top management is vital. Note Page 13 Product Quality and Development More Detail: Pages 55-65 MGO 302 Operations Management © NC Simpson 2015 TQM TOOL: QFD ANALYSIS Think about the two definitions of quality. How do we relate the perceptions and expectations of our customers to actual specifications that we can build by? Step One: Determine what features our customers consider valuable. Example: A Tennis Ball Step Two: Now survey our customers to find out how they rate several existing brands with respect to the features discovered in Step One. Survey Results: Customer Attributes: Brand A Note Page 14 Product Quality and Development Brand B Brand C Brand D MGO 302 Operations Management © NC Simpson 2015 Step Three: Now we rate these brands according to their technical specifications. Rating Results: Technical Specifications: Brand A Note Page 15 Product Quality and Development Brand B Brand C Brand D MGO 302 Operations Management © NC Simpson 2015 Step Four: Use the data from steps two and three to compute a correlation matrix between the value features and the functional characteristics. Strong correlations mean what? RELATIONSHIP MATRIX ( Easy to See Stays Bouncy Stays Clean look for QFD_Matrix.xls on UBlearns): Thickness Density % Nylon % Latex in of Shell of Nap in Nap Shell -0.36 0.94 0.41 0.24 0.99 -0.50 0.52 -0.99 -0.06 0.87 0.48 -0.07 Note Page 16 Product Quality and Development More Detail: Page 58 and Scenario 1 starting page 59 MGO 302 Operations Management © NC Simpson 2015 ‘HOUSE OF QUALITY’: Note Page 17 Product Quality and Development More Detail: Pages 66-72, including Scenarios 2a and 2b MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON PRODUCT QUALITY AND DEVELOPMENT: Video tutorials explaining each of these questions are available on UBlearns. 1. Older, more traditional quality control systems often rely heavily on: a) trust b) luck c) talent d) inspection e) good looks 2. Which of the following is (are) true? I. A fishbone diagram is more useful than a histogram when conducting Pareto analysis. II. The concept of “quality as conformance” is historically older than the concept of “quality as improvement.” III. ‘Remanufacturing’ refers to a ‘cradle-to-grave’ model of product design and production. a) I only b) II only c) I and III d) II and III e) I, II and III 3. Which of the following is (are) principles of Total Quality Management? I. Fix problems at their source. II. Quality is the responsibility of the Quality Control Department, and no one else. III. Seek continuous improvement. a) I only. b) II only. c) III only. d) I and III. e) I, II, and III. 4. Which of the following is (are) true? I. Unclear instructions and poor after sales service could lower a customer’s perception of a product’s quality. II. Total Quality Management relies heavily on professional inspectors to catch all defects before they are shipped to the customer. III. Total Quality Management attempts to involve everyone in an organization in the effort to achieve quality. a) I only. b) I and II. c) II only. Note Page 18 Product Quality and Development d) II and III. e) I and III. MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON PRODUCT QUALITY AND DEVELOPMENT, CONT’D: 5. Suppose you manufacture high quality stereo equipment. Unfortunately, you hear that customers think just the opposite: they say that your equipment “doesn’t work half of the time.” You go out into your warehouse and inspect several hundred boxes of your own equipment. Everything that you inspect works perfectly. Which of the following might be the source of your reputation for poor quality stereo equipment? I. Equipment is being damaged during shipment to the customer. II. The instructions packed with the stereo equipment are unclear and customers are not assembling the equipment correctly. III. The stereo equipment does not conform to your specifications. a) I only. b) II only. c) III only. d) I and II. e) I, II, and III. 6. Beserk Tennis Ball company has just conducted a QFD analysis that resulted in the following “House of Quality” diagram: An intern who worked on the project said that one of the correlation coefficients calculated when creating the relationship matrix, “Came out crazy strong… it was -0.99978!” Which of the following list is most likely to have been the relationship that earned that particular ‘crazy strong’ score? a) the relationship between ‘Thickness of shell’ and ‘Density of Nap’ b) the relationship between ‘Easy to See’ and ‘Density of Nap’ c) the relationship between ‘Stays Clean’ and ‘Depth of Nap’ d) the relationship between the ‘Doesn’t Bounce Funny and ‘Thickness of shell’ e) the relationship between the ‘Doesn’t Bounce Funny and ‘Easy to See’ Note Page 19 Product Quality and Development Similar to this: Chapter 3, Scenario #18 MGO 302 Operations Management © NC Simpson 2015 FORECASTING Qualitative Approaches Quantitative Approaches *Expert Opinion Panels *Consumer Surveys *Delphi Groups Associative Models *Regression Analysis Time Series Analysis *Moving Averages *Exponential Smoothing *Seasonal Relatives Note Page 20 Forecasting More Detail: Pages 86-88 MGO 302 Operations Management © NC Simpson 2015 TIME SERIES TECHNIQUE: Moving Averages To forecast the next value, simply average the “n” most recent values! EXAMPLE: Month Forecast: Actual 2 Month Monthly Sales Moving Average Jan. 1,000 Feb. 2,000 March 3,000 Forecast: 3 Month Moving Average April May WHAT LENGTH OF MOVING AVERAGE SHOULD YOU USE? Note Page 21 Forecasting MGO 302 Operations Management © NC Simpson 2015 TIME SERIES TECHNIQUE: Simple Exponential Smoothing To forecast the next value, consider this: New Forecast = Old Forecast + Fraction * ( Actual Demand - Old Forecast) EXAMPLE: Month Actual Monthly Sales Forecast: = 0.05 Forecast: = 0.90 Jan. 1,000 1,000 1,000 Feb. 2,000 March April May WHAT SHOULD YOU USE? Note Page 22 Forecasting More Detail: Pages 107-113 including Scenarios 4a and 4b MGO 302 Operations Management © NC Simpson 2015 MEAN ERROR (ME) Is your forecasting system doing a good job? Average its errors! ERROR = ACTUAL - FORECAST ACTUAL: MAY JUNE JULY AUGUST 10 20 30 5 20 35 15 FORECAST: 5 ERROR: MEAN SQUARE ERROR (MSE) ? First square the errors, then average them. MEAN ABSOLUTE DEVIATION (MAD)? Average the absolute values of the errors. MEAN ABSOLUTE PERCENT DEVIATION (MAPE)? Average the absolute values of the errors. TRACKING SIGNAL? Divide the sum of the errors by the MAD. Note Page 23 Forecasting More Detail: Pages 89-93 including Scenario 1 Similar Practice: End of Chapter Scenario #29 MGO 302 Operations Management CAUSAL MODELING… Note Page 24 Forecasting © NC Simpson 2015 MGO 302 Operations Management © NC Simpson 2015 LINEAR REGRESSION Livingston Medical Services provides medical transportation. Comparing clients to actual transports for seven ‘courtesy van’ contracts suggests a relationship between these issues: What is the linear regression equation that best expresses this relationship? ( look for Livingston Medical Services Example.xls on UBlearns): Note Page 25 Forecasting More Detail: Pages 96-99 including Scenarios 2a and 2b Similar Practice: End of Chapter Scenarios #27, #28 and #32 MGO 302 Operations Management © NC Simpson 2015 SYSTEMATIC VARIATION TIME SERIES TECHNIQUE: Seasonal Indices To create a set of seasonal indices: 1. Obtain a sample of time series data and calculate the average value for each season. 2. Now average the season averages. 3. Divide each season average (the result of step 1) by the average of the averages (the result of step 2). The result is your index value for that season. Example: Parking Tickets on North Campus Spring Summer Fall 30 40 50 30 150 170 160 170 (including Winter Intercession) 2011 2012 2013 2014 Note Page 26 Forecasting 100 120 110 100 MGO 302 Operations Management © NC Simpson 2015 WHAT ARE SEASONAL INDICES USED FOR? * To Seasonalize Data Multiply the data by the appropriate seasonal index. Why would you do this? * To De-seasonalize Data Divide the data by the appropriate seasonal index. Why would you do this? Note Page 27 Forecasting More Detail: Pages 103-107 including Scenarios 3a, 3b and 3c Similar Practice: End of Chapter Scenarios #26 and #31 MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON FORECASTING: Video tutorials explaining each of these questions are available on UBlearns. 1. Given an actual demand of 59 in March, a March forecast of 64, and an “alpha” () of 0.3, what would the forecast for April be using exponential smoothing? a) 36.9 b) 57.5 c) 60.5 d) 62.5 e) 65.5 Similar to this: Chapter 4 Quick Start #18 2. Simple exponential smoothing is being used to forecast demand. The previous forecast of 66 turned out to be four units less than actual demand. The next forecast is 66.6, implying an “alpha” (), equal to: a) 0.01 b) 0.1 c) 0.15 d) 0.20 e) 0.60 Similar to this: Chapter 4 Ramp Up #21 3. Jim’s Bicycle Company has provided you with the following data on their past sales of unicycles: October 2012 November 2012 December 2012 January 2013 40 42 44 31 Similar to this: Chapter 4 Scenario #25 and #30 Predict sales for February 2013, using a 3-month moving average. a) -6.00 b) 39.00 c) 39.25 e) 52.33 d) 42.00 4. Here are the errors associated with a particular forecast over the past five months, in chronological order: 2, 5, 0, -5, -10. Which of the following statements is (are) true? I. The forecast was too high during the fifth month. II. The mean error over these five months is 4.4. III. The forecast was perfectly accurate during one of the months. a) II only Note Page 28 Forecasting b) III only c) I and III d) II and III Similar to this: Chapter 4 Ramp Up #23 e) I, II and III MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON FORECASTING, CONT’D: Below are the seasonal relatives (also known as seasonal index numbers) that describe the weekly fluctuation in the number of distinct users logging into a certain website daily, also known as the number of unique appearances per day. Day of the Week Monday Tuesday Wednesday Thursday Friday Saturday Sunday Seasonal Relative (or Index Number) for Unique Appearances 1.25 1.01 1.03 1.09 0.94 0.66 1.01 Similar to this: Chapter 4 Scenario #26 Please answer the following two questions, based on this information. 5. Which of the following is (are) true about the number of unique appearances on the website? I. Monday is the busiest day of the week in terms of the number of unique appearances on the website. II. Only 66% of users log in on Saturday. III. Fridays are busier than Thursdays in terms of the number of unique appearances that day. a) I only b) II only c) III only d) I and II e) II and III 6. Suppose someone has given you a forecast for the first full week of next month: an overall number of 3,500 unique appearances will be recorded throughout the seven days of that week. Based on this estimate, which of the following is the most logical estimate of the number of unique appearances during the Thursday of that week? a) 459 b) 500 Note Page 29 Forecasting c) 545 d) 625 e) 3815 MGO 302 Operations Management © NC Simpson 2015 CAPACITY PLANNING CONCEPTS: TYPES OF CAPACITY * Design Capacity- the maximum possible rate of output that can be achieved * Effective Capacity- the rate of output the firm is capable of achieving, given preventative maintenance, set-up time, etc. * Actual Output- whatever rate of output is actually achieved Note Page 30 Capacity Planning MGO 302 Operations Management © NC Simpson 2015 CAPACITY PLANNING CONCEPTS: MEASURING CAPACITY * “Efficiency” - * “Utilization”- Note Page 31 Capacity Planning More Detail: Pages 125-127 including Scenario 1 MGO 302 Operations Management © NC Simpson 2015 CAPACITY STRATEGY CUSTOMER DEMAND TIME Note Page 32 Capacity Planning MGO 302 Operations Management © NC Simpson 2015 ANOTHER CAPACITY STRATEGY CUSTOMER DEMAND TIME Note Page 33 Capacity Planning More Detail: Pages 129-132 MGO 302 Operations Management © NC Simpson 2015 CAPACITY PLANNING TOOL: BREAK-EVEN ANALYSIS When will revenue cover your costs, given you invest in a particular process? Note Page 34 Capacity Planning MGO 302 Operations Management © NC Simpson 2015 BREAKEVEN ANALYSIS: Pick a Cargo Ship… Vessel Variable Fixed Cost Cost per Ton Revenue per Ton When do you break even? American Century Sam Laud Note Page 35 Capacity Planning More Detail: Pages 127-129 including Scenario 2 Similar Practice: End of Chapter Scenario #30 MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON CAPACITY PLANNING: Video tutorials explaining each of these questions are available on UBlearns. 1. A production facility has a design capacity of 200 units a day and an effective capacity of 190 units. Which of the following are potential “determinants” of its effective capacity, accounting for the gap between 200 and 190? I. The need for periodic maintenance of the equipment in the facility. II. The actual output of the facility. III. Lunch breaks and coffee breaks taken during a typical day in the facility. a) I only b) I and II c) II only d) I and III e) I, II and III 2. The Kitti Kreme Donut production facility consists of three identical donut production lines, each of which operated at 80% efficiency last week. If this facility produced a total of 30,000 donuts last week, what is the apparent effective capacity of one of Kitti Kreme’s donut production lines? Similar to this: a) 8,000 donuts b) 10,000 donuts c) 12,500 donuts Chapter 5 Ramp d) 24,000 donuts e) 37,500 donuts Up #24 3. Costs that continue to be incurred even if no units are produced by a facility are called a) fixed costs b) variable costs c) breakeven costs d) marginal costs e) relational costs Medic Clinic is considering purchasing a new blood analysis machine for $60,000. Medic Clinic can charge $25.00 for each blood sample analyzed, while the actual cost of the blood analysis would only be $5.00. The new machine has a design capacity of 6,000 blood analyses a year and an effective capacity of 5,000 blood analyses a year. The following three questions concern Medic Clinic. 4. How many blood analyses would have to be performed in order for Medic Clinic to break even? a) 12,000 b) 5,000 c) 3,000 d) 2,400 e) 1,000 5. Suppose Medic Clinic expects to perform 4,500 blood analyses next year, if it buys the new machine. What would be the utilization of this machine? a) 0% b) 75% c) 83% d) 90% e) 100% 6. How may blood analyses would Medic Clinic have to perform each year, in order for the use of the new machine to be 80% efficient? a) 1,000 b) 3,200 c) 4,000 d) 4,800 e) 5,000 Similar to this: Note Page 36 Capacity Planning Chapter 5 Quick Start #14, #15,#16 MGO 302 Operations Management © NC Simpson 2015 WAITING LINE THEORY: THE BASIC ANATOMY OF A LINE CUSTOMER ARRIVAL ISSUES * SOURCE? * DISTRIBUTION OF ARRIVAL? * DEGREE OF PATIENCE? Note Page 37 Waiting Lines MGO 302 Operations Management © NC Simpson 2015 WAITING LINE ISSUES * LENGTH? * NUMBER? * QUEUE DISCIPLINE? SERVICE SYSTEM ISSUES * DISTRIBUTION OF SERVICE TIME? * STRUCTURE? Note Page 38 Waiting Lines More Detail: Pages 132-139 MGO 302 Operations Management © NC Simpson 2015 Global Freightways depots are open to drop-off air cargo 24 hours a day, although only one agent is available during nonbusiness hours. A single agent requires an average of 20 minutes to complete data entry, check cargo, and process the payment for the shipment. At the Hong Kong depot, an average of one client arrives each hour during weeknight non-business hours. CUSTOMER ARRIVALS Source? Distribution of Arrival? Degree of Patience? WAITING LINE Length? Number? Queue Discipline? SERVICE SYSTEM Structure? Distribution of Service Time? Note Page 39 Waiting Lines MGO 302 Operations Management © NC Simpson 2015 AT THE HONG KONG DEPOT DURING NON-BUSINESS HOURS: * What is the probability that an arriving customer will have to wait? * What proportion of the time will the agent be idle? * What is the probability of exactly one customer being at the Global Freightways Depot? * What is the average length of the line at the Global Freightways Depot? * What is the average number of customers at the Global Freightways Depot? * What is the average wait to speak to the agent? *What is the average total amount of time spent by a customer at the depot? Note Page 40 Waiting Lines More Detail: Pages 140-142, including Scenario 3 Similar Practice: End of Chapter Scenario #34 MGO 302 Operations Management © NC Simpson 2015 AN ALTERNATE (NON-MATHEMATICAL) VIEW… Absolute vs. Perceived Time People do not perceive time at a constant rate. One ten minute delay can be longer than another ten minute delay, given the person waiting was subject to certain conditions. What are those conditions? A Ten Minute Delay Will Be Longer If It Is... Note Page 41 Waiting Lines How Can This Be Used to Make Shorter Waits? More Detail: Pages 143-145 MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON WAITING LINES: Video tutorials explaining each of these questions are available on UBlearns. All trucks traveling on I-75 south of Gainesville, Florida must stop at a weigh station. This station has one set of scales, which can weigh an average of 18 trucks an hour, exponentially distributed. Trucks arrive at the weigh station at an average of 15 an hour, Poisson distributed. Note the formulas necessary to analyze this weigh station are included with your exam. 1. What is the average delay a truck suffers at the I-75 weigh station? That is, what is the average total time the truck spends waiting and being weighed? (In minutes!) a) 0.2778 minutes b) 0.3333 minutes c) 4.1667 minutes Similar to this: d) 16.6667 minutes e) 20 minutes Chapter 5 Quick Start 2. What is the probability that there are no trucks at the I-75 weigh station? a) 0.0000 b) 0.1667 c) 0.2778 d) 0.3333 e) 0.8333 #18 through #23 and Scenario #35 3. You are observing a line of people forming at the ordering counter of Starbuck’s Coffee on the North Campus of UB. This line has at least fifteen people in it, waiting to order coffee. Suddenly you notice two people walk through the front door of Starbuck’s, stop when they see the other fifteen people waiting to order, shake their heads, turn around and exit Starbuck’s again immediately. What you have just witnessed is an instance of customer impatience best known as: a) switching b) balking c) reneging d) dodging e) restlessness 4. Suppose you are taking a 105 minute airplane flight from Buffalo, NY to Atlanta, GA. This flight does not occur at mealtime, but the cabin staff still provides you with a small drink and two packs of honey-roasted peanuts. You eat the peanuts and study the evacuation instructions and the airline magazine you found in the pocket of the seat in front of you. Which of the following best describes the psychological waiting principle both you and the airline are employing to shorten this 105 minute waiting period? I. In-process waits are shorter than pre-process waits. II. Unfair waits are longer than fair waits. III. Occupied waits are shorter than unoccupied waits. a) I only. b) II only. Note Page 42 Waiting Lines c) III only. d) I and II. e) I, II, and III. MGO 302 Operations Management © NC Simpson 2015 SIX OLD EXAM QUESTIONS ON WAITING LINES, CONT’D: Cars traveling from Canada to the United States through the Thousand Islands Border Crossing must stop for US Customs and Immigration. During the stop, each passenger in the car will present a passport for inspection by a US Customs Officer, answer questions, and declare certain valuables that may be in the car. On average, it takes a Customs Officer about five minutes to inspect passports and release a car for entry into the United States. Since the Thousand Islands Border Crossing is not heavily traveled at night, US Customs and Immigration only keeps one lane open at the checkpoint plaza and one officer on duty to process arriving cars. Between midnight and 6:00 AM, cars arrive on at the Border Crossing plaza at an average rate of two per hour. 5. Assuming this scenario meets the assumptions of the M/M/1 model, what percent of the time is the US Customs Officer busy with inspecting the passports from arriving cars between midnight and 6:00 AM? a) 16.7% b) 33% c) 40% d) 67% e) 167% 6. When a car arrives at this checkpoint between midnight and 6:00 AM, what is the average length of time it must wait before speaking with this US Customs Officer? a) 0.02 minutes b) 0.03 minutes c) 1 minute d) 2 minutes Similar to this: Chapter 5, Scenario #36 and #37 Note Page 43 Waiting Lines e) 6 minutes