Q&A Hero

Q: Complete the following MRP record using the FOQ rule:

Q: Complete the following MRP record using the L4L rule:

Q: Complete the following MRP record using the POQ rule.

Q: Job Process Time Due Date Days Since Arrival A 5 7 11 B 9 5 9 C 7 9 9 D 2 3 7 E 3 4 5 F 8 8 2 Use the information in the preceding table and sequence the six jobs using first come, first served (FCFS) and earliest due date (EDD). Calculate the average flow time and average past due. It is now time zero.

Q: Job Process Time (days) Due Time (days) Days Since Arrival A 2 7 12 B 8 16 9 C 4 4 8 D 10 17 5 E 5 15 3 F 12 18 2 Use the information in the preceding table and sequence the six jobs using FCFS and EDD. The jobs are listed in the order of their arrival. Calculate the average flow time and average past due. It is now time zero.

Q: Wally's Bar operates seven days a week. The daily requirements (in workers) are estimated as follows: Each worker is required to work five days per week, and each must have two consecutive days off. What is the minimum number of workers needed? Provide the days off that each worker receives.

Q: Jim's Restaurant operates seven days a week. The daily requirements (in workers) are estimated as follows: Each worker is required to work five days per week, and each must have two consecutive days off. What is the minimum number of workers needed? Provide the days off that each worker receives.

Q: A service firm uses a level utilization production-planning horizon of six months. They have developed a forecast for the coming three quarters that appears in the table. They can add no more than 15% of their production capacity as overtime. What is the minimum cost sales and operations plan? Can they deliver on their forecast?

Q: A service firm uses a level utilization production-planning horizon of six months. They have developed a forecast for the coming six months that appears in the table. They can add no more than 33% of their production capacity as overtime. What is the minimum cost sales and operations plan?

Q: A retailer experiences a seasonal demand pattern for its services. Labor requirements over a typical six-month period follow. Period 1 2 3 4 5 6 Requirement 12 10 12 8 9 8 Costs associated with operations are as follows: Wages = $1,500 per worker per month Hiring cost = $1,500 per worker Layoff cost = $1,500 per worker The current workforce level is 11 workers. Use the spreadsheet approach and the preceding data to answer the following questions. a. What is the total cost of the staffing plan, including the cost of regular wages, hiring, and layoffs using a chase strategy with hiring and layoffs, but no overtime? b. What is the total cost of the staffing plan, using a level strategy in which no overtime is allowed, and the undertime paid for? c. Suppose that overtime is allowed up to 25% of the regular-time capacity, and that overtime wages are 150% of the regular-time rate. What is the total cost of the level strategy with overtime and undertime that also minimizes undertime?

Q: A retailer experiences a seasonal demand pattern for its services. Labor requirements over a typical six-month period follow. Period 1 2 3 4 5 6 Requirement 7 8 9 11 12 7 Costs associated with operations are as follows: Wages = $2,000 per worker per month Hiring cost = $1,000 per worker Layoff cost = $1,500 per worker The current workforce level is 10 workers. Use the spreadsheet approach and the preceding data to answer the following questions: a. What is the total cost of a staffing plan, including the cost of regular wages, hiring, and layoffs using a chase strategy with hiring and layoffs, but no overtime? b. What is the total cost of the staffing plan, using a level strategy in which no overtime is allowed and the undertime paid for? c. Suppose that overtime is allowed up to 25% of the regular-time capacity, and that overtime wages are 150% of the regular-time rate. What is the total cost of the level strategy with overtime and undertime that also minimizes undertime?

Q: A store has collected the following information on one of its products: Demand = 5,000 units/year Ordering costs = $12/order Holding costs = $4/unit/year Lead-time = 5 days weeks Unit cost = $748/unit Number of weeks per year = 50 weeks a. The firm currently orders 500 units per order. What is the total cost of ordering and holding these goods under this system? b. Determine their economic order quantity and cost of ordering and holding goods using the EOQ. c. Form the ratio of the order quantities under the old policy and EOQ. Form the ratio of the EOQ to the old order quantity. Then form the ratio of their total system costs under the two ordering policies. Average these two ratios and compare this number with the ratio of the old total cost with the total cost under an EOQ policy. d. How do they compare?

Q: An assistant manager is reviewing the costs associated with one of the store's better-selling products. The data available follows. Demand = 400 units/year Order cost = $25/order Holding cost = 50/unit/year a. They currently order a one-year supply. What are the total annual ordering cost and holding cost for this order size? b. What would be the EOQ and its associated ordering and holding costs?

Q: An assistant manager is reviewing the costs associated with the store's best-selling product. The data available follows. Demand = 500 units/year Order cost = $40/order Holding cost = $7/unit/year a. What is the EOQ and its associated ordering and holding costs? b. If annual demand doubles and all other costs remain the same, what is the new EOQ and total annual cost?

Q: Sketch the EOQ cost curves and describe their derivation.

Q: The Hastings Company is a nation-wide wholesaler for small electronic devices. One of its most popular items is a new GPS unit called the WAMI-1,000. Hastings has gathered the following information, and has asked you to develop a continuous review inventory control system for this item: Order quantity for each order placed with manufacturer = 50,000 units Average demand = 5,000 units/week Standard deviation of weekly demand = 1,000 units Average lead time = 4 weeks Standard deviation of lead time: 1 week Cycle-service level = 90% (z for 90% = 1.28) a. What is the standard deviation of demand during lead time? b. What is the safety stock level that should be carried for the WAMI-1,000? c. What is the reorder point for the WAMI-1,000? d. Summarize the actions Hastings should take using your new inventory system. e. If Hastings decides to increase its cycle-service level to from 90% to 99% (z for 99% = 2.33), how does this change the actions that should be taken?

Q: a. What is the expected demand during lead time? b. What is the standard deviation of demand during lead time? c. What is the average safety stock? d. What is the reorder point? e. If the company desired to lower the reorder point, which of these initiatives would lower it by the greatest amount – reducing the lead time by 10%, reducing the standard deviation of lead time by 10%, or reducing the service level by 10%? Answer:

Q: The Hastings Company is a nation-wide wholesaler for small electronic devices. One of its most popular items is a new GPS unit called the WAMI-1,000. Hastings has gathered the following information, and has asked you to develop a continuous review inventory control system for this item: Order quantity for each order placed with manufacturer = 10,000 units Average demand = 1,000 units/week Standard deviation of weekly demand = 200 units Average lead time = 5 weeks Standard deviation of lead time: 1.5 weeks Cycle-service level = 90% (z for 90% = 1.28) a. What is the standard deviation of demand during lead time? b. What is the safety stock level that should be carried for the WAMI-1,000? c. What is the reorder point for the WAMI-1,000? d. Summarize the actions Hastings should take using your new inventory system. e. If Hastings decides to increase its cycle-service level from 90% to 95% (z for 95% = 1.65), how does this change the actions that should be taken?

Q: A store has collected the following information on one of its products: Demand = 4,000 units/year Ordering costs = $15/order Holding costs = $2/unit/year Lead-time = 5 days weeks Number of weeks per year = 50 weeks If a firm uses the continuous review system to control the inventory, what would be the order quantity?

Q: A store has collected the following information on one of its products: Demand = 10,000 units/year Standard deviation of weekly demand = 25 units Ordering costs = $30/order Holding costs = $4/unit/year Cycle-service level = 95% (z for 95% = 1.65) Lead-time = 2 weeks Number of weeks per year = 50 weeks a. If a firm uses the continuous review system to control the inventory, what would be the order quantity and reorder point? b. The firm decided to change to the periodic review system to control the item's inventory. For the most recent review, an inventory clerk checked the inventory of this item and found 200 units. There were no scheduled receipts or backorders at the time. How many units should be ordered? (Hint: Use the EOQ model to derive P, the time between reviews.)

Q: A store has collected the following information on one of its products: Demand = 4,500 units/year Standard deviation of weekly demand = 12 units Ordering costs = $40/order Holding costs = $3/unit/year Cycle-service level = 90% (z for 90% = 1.28) Lead-time = 2 weeks Number of weeks per year = 52 weeks a. If a firm uses the continuous review system to control the inventory, what would be the order quantity and reorder point? b. The firm decided to change to the periodic review system to control the item's inventory. For the most recent review, an inventory clerk checked the inventory of this item and found 300 units. There were no scheduled receipts or backorders at the time. How many units should be ordered? (Hint: Use the EOQ model to derive P, the time between reviews.)

Q: Ten months of data and the forecasts for those same periods are in the table below. Use mean bias, MAD, and MAPE to analyze the accuracy of the forecasts. Month Actual Forecast January 42 37 February 58 50 March 58 58 April 77 67.5 May 91 84 June 102 96.5 July 124 113 August 148 136 September 171 159.5 October 177 174

Q: Calculate three forecasts using the following data. First, for periods 4 through 10, develop the exponentially smoothed forecasts using a forecast for period 3 (F3) of 120.0 and an alpha of 0.3. Second, calculate the three-period moving-average forecast for periods 4 through 10. Third, calculate the weighted moving average for periods 4 through 10, using weights of .60, .30, and .10. Calculate the mean absolute deviation (MAD) and the cumulative sum of forecast error (CFE) for each forecasting procedure. Which forecasting procedure would you select? Why? Month Demand 1 120 2 115 3 125 4 119 5 127 6 114 7 120 8 124 9 116 10 137

Q: Calculate three forecasts using the following data. First, for periods 4 through 10, develop the exponentially smoothed forecasts using a forecast for period 3 (F3) of 45.0 and an alpha of 0.4. Second, calculate the three-period moving-average forecast for periods 4 through 10. Third, calculate the weighted moving average for periods 4 through 10, using weights of .70, .20, and .10, with 0.70 applied to the most recent data. Calculate the mean absolute deviation (MAD) and the cumulative sum of forecast error (CFE) for each forecasting procedure. Which forecasting procedure would you select? Why? Month Demand 1 45 2 48 3 43 4 48 5 49 6 54 7 47 8 50 9 46 10 47

Q: Consider the activities, durations, and predecessor relationships in the following network. Draw the network and answer the questions that follow. Activity Description Immediate Predecessor(s) Optimistic (Weeks) Most Likely (Weeks) Pessimistic (Weeks) A --- 4 7 10 B A 2 8 20 C A 8 12 16 D B 1 2 3 E D, C 6 8 22 F C 2 3 4 G F 2 2 2 H F 6 8 10 I E, G, H 4 8 12 J I 1 2 3 a. What is the expected time for activity B? b. What is the variance for activity B? c. Based on the calculation of estimated times, what is the critical path? d. What is the estimated time of the critical path? e. What is the activity variance along the critical path? f. What is the probability of completion of the project before week 42?

Q: The following table contains a list of activities, with precedence requirements and crash costs. All start and finish times and crash costs are on a per-week basis. a. Determine the project cost and duration without crashing. b. Determine the least expensive project cost if the duration is to be 10% shorter than normal project duration. c. Determine the least expensive project cost if the duration is to be 20% shorter than normal project duration. d. Create a graph that shows project expediting cost plotted as a function of the reduction in project duration. Activity Normal Time Crash Time Normal Cost Crash Cost Predecessor A 10 7 2,000 2,600 B 12 8 1,500 2,000 A C 16 12 2,200 3,000 A D 8 7 2,500 3,000 B E 13 10 1,950 2,275 C F 9 8 800 1,000 D G 24 29 3,650 4,000 E, F H 17 14 1,200 1,800 G

Q: Draw the network corresponding to the following information. Also, complete the table, identify the critical path, and specify project completion time. Activity Immediate Predecessor(s) Time (Weeks) A --- 3 B --- 4 C A 6 D B 9 E B 6 F C, D 6 G D, E 8 H G, F 9 Activity Earliest Start Earliest Finish Latest Start Latest Finish Slack A B C D E F G H

Q: The Peeps factory can be described as a three step process consisting of Mixing, Forming, and Packaging. Peeps are made in batches of 1,000 and have a daily demand of 75,000 units during what the plant manager likes to call "the Peep season." Mixing has a cycle time of .02 seconds with a setup time of 30 seconds; Forming has a setup time of 24 seconds and a cycle time of .03 seconds, and Packaging has a setup time of 15 seconds with a cycle time of .04 seconds. Each process step is handled by one operator, who is available for 8 hours a day. What is the process bottleneck if each process step is assumed to have 100% uptime?

Q: Burdell Salad Dressings uses a Kanban system. The daily demand for corrugated boxes used in packaging its dressings is 300 boxes. The average waiting time for a container of boxes is 0.25 day. The processing time for a container of boxes is 0.1 day, and a container holds 10 boxes. If Burdell wishes to use a 5% policy variable, what is the level of work in process inventory in their plant?

Q: Champion Cooling Company uses a kanban system at their location in the Oklahoma City Metroplex. The daily demand for fans is 2,000 and management insists on using an alpha level of 0.1. They use containers that hold 24 items and takes 0.02 of a day to process. It takes 0.08 of a day to get a container filled and for it to wait during its cycle. How many containers should they use? If they use the nearest integer value number of containers, what is the actual system alpha?

Q: Champion Cooling Company uses a kanban system at their location in the Oklahoma City Metroplex. The daily demand for fans is 2,000 and management insists on using an alpha level of 0.1. They use containers that hold 20 items and takes 0.04 of a day to process. It takes 0.07 of a day to get a container filled and for it to wait during its cycle. How many containers should they use? If they use the nearest integer value number of containers, what is the actual system alpha?

Q: Champion Cooling Company uses a kanban system at their two locations in the Oklahoma City Metroplex. The daily demand for fans is 2,000 at each location and management insists on using the same alpha level (0.1) at both locations. Location Reno uses containers that hold 20 items and takes 0.04 of a day to process a container. It takes 0.07 of a day to get a container filled and for it to wait during its cycle. Location Western uses containers that hold 24 items and takes 0.02 of a day to process a container. It takes 0.08 of a day to get a container filled and for it to wait during its cycle. Which location has the higher level of inventory? Assume that both locations round up to the next highest integer number of containers.

Q: Degan's Salad Dressings uses a Kanban system. The daily demand for corrugated boxes used in packaging its dressings is 300 boxes. The average waiting time for a container of boxes is 0.25 day. The processing time for a container of boxes is 0.1 day, and a container holds 10 boxes. If Burdell wishes to use a 10% policy variable, how many containers are needed?

Q: Happiness, Inc. uses a Kanban system. The daily demand for the most critical part, the Smylie, is 400 units over an eight-hour production period. The average waiting time for a container of Smylies is 30 minutes. The processing time for a container filled with Smylies is 6 minutes, and a container holds 5 units. If the company wishes to use a 5% policy variable, how many containers are needed?

Q: Jones Electric Motors uses a Kanban system to make motors for several garage door companies in the southeastern United States. The daily demand for motor housings used in manufacturing is 100 units. The average waiting time for a container of parts is 0.2 day. The processing time for a container of housings is 0.1 day, and a container holds 5 housings. If Jones wishes to use a 10% policy variable, how many containers are needed?

Q: Balance the line in order to achieve maximum output for this eight-activity product. Then balance the line to maximize the efficiency of the operation. How do the levels of output (assume an eight-hour day) and line efficiencies compare? Task Time (min) Predecessor 1 10 --- 2 8 Task 1 3 9 Task 1 4 2 Task 2 5 6 Task 3 6 12 Task 4, Task 5 7 7 Task 5 8 5 Task 6, Task 7

Q: Balance the line in order to achieve maximum output for this ten activity product. Determine the number of units produced in a seven hour work day and the total idle time in hours. Task Time (sec) Predecessor Z 40 --- Y 30 Z X 80 Z W 75 X, Y V 15 W T 55 W S 35 V R 40 T Q 10 R M 40 S, R

Q: Balance the assembly line using the following task information contained in the table. The desired output is 360 units per day. Available production time per day is 480 minutes. What is the efficiency for the balanced assembly line? Work Element Time (Sec.) Immediate Predecessor(s) A 30 --- B 20 A C 50 A D 45 B E 30 B F 55 C, D G 35 D, E H 40 F

Q: Balance the assembly line for the tasks contained in the table. The desired output is three units per hour. Available production time per day is eight hours. What is the theoretical minimum number of stations? What is the efficiency for the balanced assembly line? Work Element Time (Min.) Immediate Predecessor(s) A 5 --- B 8 A C 12 A D 11 B E 5 C F 6 D G 4 D H 12 E I 14 G, H J 9 F K 8 I L 3 K, J

Q: Balance the assembly line for the tasks contained in the table. The desired output is 240 units per day. Available production time per day is 480 minutes. What is the efficiency for the balanced assembly line? Work Element Time (Sec.) Immediate Predecessor(s) A 40 --- B 45 --- C 55 A D 55 B E 65 B F 40 C, D G 25 D, E

Q: The single milling machine at Fred's Manufacturing was severely overloaded last year. The plant operates 8 hours per day, 5 days per week, and 50 weeks per year. Management prefers a capacity cushion of 20 percent. Two major types of products are routed through the milling machine. The annual demand for product A is 4,000 units and 3,000 units for product B. The batch size for A is 20 units and 30 units for B. The standard processing time for A is 0.5 hours/unit and 0.8 for B. The standard setup time for product A is 2 hours and 8 hours for product B. How many new milling machines are required if Fred's does not resort to any short-term capacity options?

Q: A printing company works on three types of printing jobs, each of which could be produced on the same model printing machine. The predicted annual demands and typical order sizes are shown in the table. The company has 2,000 production hours available each year and requires a 10% capacity cushion to allow for preventive maintenance, breakdowns, and other unforeseen circumstances. They have floor space for five printing machines. If the time needed to set up a printing machine to switch from one job to the next is identical for all three job types, what must their setup time be to achieve their required output? Job Type Job A Job B Job C Demand 6,000 4,000 5,000 Process time per unit .8 .75 .25 Average order size 40 100 50

Q: A printing company works on three types of printing jobs, each of which could be produced on the same model printing machine. The predicted annual demands and typical order sizes are shown in the table. The company has 2,000 production hours available each year and requires a 10% capacity cushion to allow for preventive maintenance, breakdowns, and other unforeseen circumstances. How many printing machines must they have under these circumstances? Job Type Job A Job B Job C Demand 6,000 4,000 5,000 Process time per unit .8 .75 .25 Average order size 40 100 50 setup time (hours) 1 .75 .5

Q: Depict the expansionist strategy graphically as a plot of capacity against time and discuss the benefits of adopting this strategy.

Q: The seven-person maintenance function at a hospital performs both preventive and corrective maintenance on hundreds of items each month. All the workers are scheduled for 40 hours per week and there are four weeks in a month. It is the goal of the maintenance department to achieve 90% utilization with a mix of two-thirds preventive maintenance and one-third corrective maintenance. How many hours each month are spent performing preventive maintenance if they achieve their 90% utilization and correct/preventive mix targets?

Q: The seven-person maintenance function at a hospital performs both preventive and corrective maintenance on hundreds of items each month. All the workers are scheduled for 40 hours per week and there are four weeks in a month. It is the goal of the maintenance department to achieve 90% utilization with a mix of two-thirds preventive maintenance and one-third corrective maintenance. How many hours each month are spent performing corrective maintenance if they achieve their 90% utilization and correct/preventive mix targets?

Q: Lucy's Pancake House, a no-frills diner along a major interstate, has discovered that if precious employee time is not wasted on frivolous duties such as cleaning work surfaces, properly storing ingredients, and pest control, they can achieve an average output rate of 25 customers per hour. If the diner was designed to accommodate a maximum of 30 customers per hour, what is the utilization?

Q: Burdell Labs is a diagnostic laboratory that does various tests (blood tests, urine tests, etc.) for doctors' offices in the Indianapolis area. Test specimens are picked up at the doctors' offices and are transported to the testing facility, with uniform arrivals throughout the day. All tests go through two testing centers in the testing facility, Test Center A and Test Center B. A has a current capacity of 1,000 units per week, and B is capable of 1,500 units per week. The facility operates 50 weeks per year. This year (year 0), test volumes are expected to reach 1,000 units per week. Growth is projected at an additional 200 units each week through year 5 (i.e., 1,200 per week in year #1, 1,400 per week in year #2, etc.). Pre-tax profits are expected to be $5 per test throughout the 5-year planning period. Two alternatives are being considered: 1) Expand both Test Centers A and B at the end of year 0 to a capacity of 2,000 units per week, at a total cost for both Test Centers of $300,000; 2) Expand Test Center A at the end of year 0 to 1,500 units per week, matching Test Center B, at a cost of $100,000, then expanding both Test Centers to 2,000 units per year at the end of year 3, at an additional cost at that time of $250,000. Burdell Labs will not consider projects that don't show a 5th year positive net present value using a discount rate of 15%. What are the pre-tax cash flows for the two alternatives compared to the base case of doing nothing for the next five years, and what action, if any, should Burdell take?

Q: The T. H. King Company has introduced a new product line that requires two work centers, A and B for manufacture. Work Center A has a current capacity of 10,000 units per year, and Work Center B is capable of 12,500 units per year. This year (year 0), sales of the new product line are expected to reach 10,000 units. Growth is projected at an additional 1,000 units each year through year 5. Pre-tax profits are expected to be $30 per unit throughout the 5-year planning period. Two alternatives are being considered: 1) Expand both Work Centers A and B at the end of year 0 to a capacity of 15,000 units per year, at a total cost for both Work Centers of $200,000; 2) Expand Work Center A at the end of year 0 to 12,500 units per year, matching Work Center B, at a cost of $100,000, then expanding both Work Centers to 15,000 units per year at the end of year 3, at an additional cost at that time of $200,000. The King Company will not consider projects that don't show a 5th year positive net present value using a discount rate of 15%. What are the pre-tax cash flows for the two alternatives compared to the base case of doing nothing for the next five years, and what action, if any, should the company take?

Q: Larry's Wickets, Inc. is producing two types of products: A and B. Both are produced at the same machining operation. Because of demand uncertainties, the operations manager obtained three demand forecasts (pessimistic, expected, and optimistic). The demand forecasts, batch sizes (units/batch), processing times (hr/unit), and setup times (hr/batch) follow. The machines operate on two 8-hour shifts, 5 days per week, and 50 weeks per year. The manager wants to maintain a 20 percent capacity cushion. a. What is the minimum number of hours required of the machining equipment for the next year? b. How many hours of capacity can the company expect from each machine? c. What is the minimum number of machines needed (assuming no reliance on short-term options)? d. What is the maximum number of machines needed (assuming no reliance on short-term options)?

Q: The Union Manufacturing Company is producing two types of products: A and B. The demand forecasts, batch size, and time standards for the Mark I operation follow: Product A Product B Demand forecast (units/yr) 1,000 4,000 Batch size (units/batch) 20 10 Processing time (hr/unit) 3.2 4.5 Setup time (hr/batch) 10 20 The company works 250 days per year and operates 2 shifts, each covering 8 hours. If a 20 percent capacity cushion is maintained, how many new Mark I machines are required if Union does not resort to any short-term capacity options?

Q: A manufacturer enjoys both a Cpk and a CP = 2.0. How high does the process mean have to drift (in number of standard deviations) away from target in order to result in a 1% chance of making a product out of specification? Illustrate this situation (both before shift and after shift) with a diagram.

Q: MKS Inc., produces meter sticks that have a target length of 100 centimeters with upper and lower specification limits of 100.05 and 99.95 centimeters respectively. Their existing process produces meter sticks with an average length of 99.97 centimeters and a standard deviation of 0.015 centimeters. They are considering the purchase of a new machine that can hold a process output average exactly to target with a standard deviation of 0.02. Which machine will provide a better process capability index?

Q: The upper and lower specification limits for a component are 3.98 and 4.02 inches, respectively. The process standard deviation is .004, and the process average is 4.005 inches. Is this process capable of achieving four-sigma performance (the four-sigma performance target value is 1.33)?

Q: A bank randomly looks at loan applications and checks them for errors. Ten applications and the number of errors identified on the applications are found in the following table. When the process is working correctly, the average number of errors found is 2. Construct a c-chart to determine if the process is in control. Application number Number of errors 1 3 2 0 3 1 4 0 5 3 6 2 7 4 8 4 9 1 10 1

Q: A professor records the number of students who complain each week throughout the semester. If the class size is forty students, what are 3-sigma control limits for this class? Construct a control chart and interpret the data. Week number Complaints 1 5 2 2 3 7 4 1 5 3 6 2 7 8 8 1 9 3 10 5 11 4 12 6 13 3 14 1 15 4

Q: A process with a target of 25 was used to generate the following data points. Is the process properly centered? Sample 1 29.5 23 20.9 24.9 Sample 2 22.9 20.1 23.7 26.9 Sample 3 25.9 23.6 23 24.3 Sample 4 25.3 23.2 29.8 22.3 Sample 5 24.7 25.1 20.6 23 Sample 6 28.4 29.7 27.1 23.7 Sample 7 21.9 23.5 24.9 24.2 Sample 8 26.9 21.1 28.1 20.2 Sample 9 25.5 27.6 26.3 27.2 Sample 10 23.9 28.6 21.7 20.6

Q: Samples of size 4 were taken from a process that had a target of 25 ounces with upper and lower specification limits of 30 ounces and 20 ounces respectively. Create the appropriate control charts and determine whether the process is in control. Sample 1 29.5 23.0 22.0 24.9 Sample 2 22.9 22 23.7 26.9 Sample 3 25.9 23.6 23.0 24.3 Sample 4 25.3 23.2 29.8 22.3 Sample 5 24.7 25.1 24.5 23.0 Sample 6 28.4 29.7 27.1 23.7 Sample 7 21.9 23.5 24.9 24.2 Sample 8 26.9 26.2 28.1 20.2 Sample 9 25.5 27.6 26.3 27.2 Sample 10 23.9 28.6 21.7 20.6

Q: The defect rate for a product has historically been about 2.0%. What are the upper and lower control chart limits if you wish to use a sample size of 100 and 3-sigma limits?

Q: The management of a line that fills cereal boxes wants the box filled at 32.2 ounces. When the process is in control, the standard deviation is .1 ounces. a. Construct the upper and lower control limits for a 3-sigma x-bar chart using a sample size of five. b. The results from the last 10 samples follow. Is the process in control?

Q: Construct a 3-sigma and R-chart for the length in centimeters of a part from the following table. Sample # Observation 1 Observation 2 Observation 3 Observation 4 1 0.486 0.499 0.493 0.511 2 0.499 0.506 0.516 0.494 3 0.496 0.5 0.515 0.488 4 0.495 0.506 0.483 0.487 5 0.472 0.502 0.526 0.469 6 0.473 0.495 0.507 0.493 7 0.495 0.512 0.49 0.471 8 0.525 0.501 0.498 0.474 9 0.497 0.501 0.517 0.506 10 0.495 0.505 0.516 0.511

Q: Thermostats are subjected to rigorous testing before they are shipped to air conditioning technicians around the world. Results from the last five samples are shown in the table. Is the process under control? Unit # Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 1 73.5 70.8 72.2 73.6 71.0 2 71.3 71.0 73.1 72.7 72.2 3 70.0 72.6 71.9 72.4 73.3 4 71.1 70.6 70.3 74.2 73.6 5 70.8 70.7 70.7 73.5 71.1

Q: Discuss the situations under which each of the following charts would be best: chart, p-chart, and c-chart.

Q: Historically, the average time to service a customer complaint has been 3 days and the standard deviation has been 0.50 day. Management would like to specify the control limits for an chart with a sample size of 10 and 3- sigma limits. The UCL for the chart would be: A) less than or equal to 3.30. B) greater than 3.30 but less than or equal to 3.40. C) greater than 3.40 but less than or equal to 3.50. D) greater than 3.50.

Q: Develop a process chart for one of the following: 1) Researching and writing a paper for your Operations Management class 2) Managing, developing and completing a team project for a Finance (or other) class 3) Planning for your job interview process as you approach graduation (including resume preparation, developing interview skills, researching company backgrounds, etc.) 4) Studying and developing a process improvement plan for a business or other process you are familiar with (e.g., fast food restaurant, obtaining tickets to a university-sponsored event, dry cleaners, book purchases for next term, and the like)

Q: Develop a process chart for a manual car wash.

Q: Because a telephone customer service center has experienced several problems, it has begun to analyze the data from customer complaints. The first step was to construct the following table. Use this data to build a Pareto chart to help identify the "vital few" problems. Process Failure Total Failures Person not available 5 Incorrect information given 12 Phone line busy 7 Long delay 39 Phone tree confusing 20 People unfriendly 17

Q: A discount store is experiencing an unacceptable number of dissatisfied customers leaving from the checkout process. Information from customer complaints about the checkout process was collected and is found in the following table. Construct a Pareto chart to identify the significant problems. Problem Type Total Problems Cashier slow 15 Price check required 9 Line too long 22 Cashier unfriendly 4

Q: Create a flowchart that displays the proper sequential use of the major graphical tools in Chapter 2, "Process Strategy and Analysis." Include a note next to each tool that explains how the output of one tool is used as the input for the following tool.

Q: An entrepreneur considers three possibilities for the production of her new product. One alternative, a job process, would have fixed costs of $22,000 and a per unit cost of $11.63. The large batch option would have a fixed cost of $54,000 and a per unit cost of $8.82. The line process would have a fixed cost of $85,000 and a per unit cost of $7.33. Graph the total cost lines and determine over what range of output each production alternative is superior.

Q: Sketch and discuss the product-process matrix for manufacturing.

Q: The three-person crew worked their way through the neighborhood, testing doorknobs and windows and slipping past security systems like a team of ninjas. Of course, they weren't ninjas, but a crew of brazen burglars, hoping to grab cash and other valuables to fence at the next level of their supply chain. Fortune smiles on them on this day in the prestigious Edmond Oaks neighborhood. A lawn maintenance crew is creating a tremendous racket mowing and edging lawns, which completely drowns out the sounds of breaking glass. Details of the day's haul appear in Table C. a. What is the multifactor productivity? b. What is the labor productivity? Table C: The Haul ITEM SALES PRICE LABOR MATERIAL Krugerrand $1,500 1 hr $2 Flat screen TV $250 .25 $1 $200 cash $200 .05 $45 Lava lamp $5 .15 $25 Rolex watch $180 .10 $1 Workers are paid at a flat rate of 20% of the sales price of the merchandise. Materials cost represents the cost of gasoline and surgical gloves, and overhead is 20% of the sales price of the merchandise.

Q: The three person crew worked their way through the neighborhood, mowing lawns, edging, applying fertilizer and weed treatments where necessary and collecting all the clippings for use as mulch as part of their new green initiative. Their pricing scheme appears in Table A and the mix of orders and service costs appear in Table B: a. What is their multifactor productivity for these orders in the prestigious Edmond Oaks neighborhood? b. Which of the service combinations provided by them is the most productive service combination from a multifactor perspective? c. What is their labor productivity for the same mix of orders? Table A: Price List SERVICE PRICE LABOR MATERIAL Mow lawn $75 1 hr $2 Edge $20 .25 $1 Fertilizer treatment $120 .25 $45 Weed prevention treatment $80 .25 $25 Multiple services 5% discount times the number of services Workers are paid at a rate of $10 per hour, and overhead is charged at 120% (or 1.2 times) labor costs. For a customer that gets both mowing and edging, their $95 bill would be discounted for two services times 5% for a total of 10% off the $95 straight charge for a cost of $85.50. A customer receiving three services would get a 15% discount off their service bill. Labor hours shown in Table A are total hours for the three-person crew. Table B: Orders Processed SERVICE # Customers Mow lawn & edge 6 Mow lawn, edge, and fertilize 3 Mow lawn, edge, and weed prevention treatment 2 Mow lawn & fertilize 2

Q: Table 1.3 The Abco Company manufactures electrical assemblies. The current process uses 10 workers and produces 200 units per hour. You are considering changing the process with new assembly methods that increase output to 300 units per hour, but will require 14 workers. Particulars are as follows: CURRENT PROCESS NEW PROCESS OUTPUT (UNITS / HOUR) 200 300 NUMBER OF WORKERS 10 14 MATERIAL COST / HOUR $120 $150 Workers are paid at a rate of $10 per hour, and overhead is charged at 140% (or 1.4 times) labor costs. Finished switches sell for $20/unit. a. Calculate the multifactor productivity for the current process. b. Calculate the multifactor productivity for the new process. c. Determine if the new process should be implemented.

Q: Barry's Tire Service completed 100 tire changes, six brake jobs, and 16 alignments in an eight-hour day with his standard crew of six mechanics. A brake specialist costs $16 per hour, a tire changer costs $8 per hour, and an alignment mechanic costs $14 per hour. The materials cost for a day was $2,000, and overhead cost was $500. a. What is the shop's labor productivity if the retail price for each respective service is $60, $150, and $40? b. What is the multifactor productivity, if the crew consisted of two of each type mechanic?

Q: Under what conditions can decision trees be useful?

Q: A chance event that has an impact on the outcome of the choice but is not under the manager's control is called a(n) ________.

Q: Decision trees are typically used in the situation of decision making under ________.

Q: The ________ nodes have probabilities associated with them in a decision tree.

Q: A(n) ________ is a schematic model of alternatives available to the decision maker, along with their possible consequences.