X-Man Problems

1. X-Man Problems Dr. Everette S. Gardner, Jr.

2. Terry Collins, CEO, Wildflour Pizza Terry Collins, CEO of Wildflour Pizza in Missouri City, Texas, collects data concerning customer complaints about delivery. Here are the results for the last 30 days: Problem Frequency Topping stuck to box lid 17 Pizza is late 35 Wrong topping/combination 9 Wrong style of crust 6 Wrong size 4 Pizza is partially eaten 3 Pizza never showed up 6 Total 80 Assignment 1. Use a Pareto chart to help Terry identify the vital delivery problems. 2. Draw a fishbone chart to help Terry identify potential causes of late pizza delivery. X-Man

3. Country Star Nissan, Rosenberg, Texas David Lee Murphy, General Manager of the Country Star Nissan dealership in Rosenberg, Texas, liked to get to the office early so that he could practice guitar riffs before the business day started. He had just cranked up “Dust on the Bottle” when his secretary, Patty Loveless, barged in. Patty looked flustered and said, “David Lee, you better put down that fool guitar and look at this letter.” The contents are reproduced below: Dear Mr. Murphy: I am writing this letter to make you aware of a nightmare I experienced in getting my 300ZX repaired in your body shop and service department. Here is a chronology of events: August 28 Dropped off the car for repair of rust damage on roof along windshield area, left rocker panel under driver’s door, and left quarter panel near end of bumper. September 1 Called to inquire about the status of the car (this was the fifth day in the shop). Was told I could pick up the car anytime after 2 pm. My boyfriend and I arrived at 5 pm but the car was not ready. I paid the bill of $443.17 and waited. At 6 pm, the car was driven up dripping wet. (I assume the car was washed but can’t you dry it off before you return it?) I got in and noticed the courtesy light in the driver’s door would not go off when the door was closed. I asked for help and Pam Tillis, body shop manager, could not figure out what was wrong. She removed the bulb and told me to come back after Labor Day. I started the engine and drove off but the voice warning “Left door is open” repeatedly sounded. There was no way to turn it off. I returned to Ms. Tillis and told her to keep the car until it was fixed. Ms. Tillis told me to call the next day (Saturday). September 2 I called Ms. Tillis at 10:30 am. She said that the car had not been looked at yet. She promised to call back before the shop closed for the holiday but she never did. September 5 I called Ms. Tillis at 4 pm. Nothing had been done but the car would be ready the next day. X-Man

4. Country Star Nissan, Rosenberg, Texas September 6 I called Ms. Tillis at 3 pm. She said that the service department needed authorization to fix the car and they didn’t know how much it would cost. I became very upset at the hint that I would have to pay to fix the door light and voice warning. I demanded to see the service manager, Shania Twain. She assured me that I was not financially responsible for any problems caused by the body shop. Furthermore, my car would be ready the next day. September 7 Again late in the day, I called Ms. Twain. She said her best mechanic, Lorrie Morgan, had narrowed down the problem to a wire that passed several spots where body work was done. She referred the call to Ms. Morgan, who assured me that the car would be ready tomorrow. September 8 I called Ms. Twain to check on the status. She told me that the wiring was fixed but the speedometer didn’t work. Lorrie Morgan got on the line and said that when she test-drove the car, the speedometer pinned itself at the top end. She thought that one of the other mechanics must have done something to the speedometer while searching for the other problem. She told me that I could pick up the car but I would have to return in next Monday so that a subcontractor could fix the speedometer. Ms. Twain said that Ft. Bend Nissan would pay all charges. I arrived at 5 pm. As I walked up to the car, I noticed rubber molding hanging down below the driver’s door. I asked Ms. Twain to come and look at it. She said that it must have come loose while they were repairing the wiring problem. She took the car back into the shop to screw the molding back in. When she finished, the molding looked sloppy. I complained about this and Ms. Twain said they would replace the molding next Monday. Driving home, I discovered that the anti-theft light on the dash would not stop blinking. I had to remove the fuse to stop the blinking light but this de-activated the security system. September 11 On Sunday evening, I dropped the car off and left a note with my keys in the “early-bird” slot. The note listed the following problems: molding, speedometer, and security system. I explained that all of these things were o.k. when I originally brought the car in for body work. On Monday, I got a call from Tanya Tucker in the service department who said that it would cost $110 to repair the security system. The problems were in the hatchback lock and in the wiring of the system. I asked her why I had to pay for problems caused by Country Star Nissan. X-Man

5. Country Star Nissan, Rosenberg, Texas Ms. Tucker said that she had checked with the mechanics who worked on my car—there was no way they caused the problems with the security system. I told Ms. Tucker to forget the security system for now because I would take the problem up with the general manager. I asked Ms. Tucker to get the molding and speedometer fixed and get the car ready as soon as possible. September 13 Ms. Tucker called and said I could pick the car up at 8 pm. I arrived at that time and was presented a bill for $126 for speedometer repair and “miscellaneous labor” in searching for the security system problem. I refused to pay the bill. I was told to take the car home—the service manager would resolve the problem the next day. I asked about the molding and was informed that it was not in stock and must be ordered. Note that the molding was damaged on September 8. As I got into the car, I noticed that the rear-view mirror was broken off its mounting and was lying in the passenger seat. I asked to see Ms. Twain and demanded to know how something like this could happen without anyone noticing. Ms. Twain was not in but I talked to Mary Chapin-Carpenter, who said someone probably did not want to own up to it. Ms. Chapin-Carpenter went to the parts department and got a new mirror and installed it. I realize this is a long letter, but I am extremely frustrated and upset by the mistakes made by your dealership over the last three weeks. What are you going to do about it? Sincerely, Leann Rimes Assignment 1. Categorize the quality problems in this case. 2. Prepare a fishbone chart for “failure to resolve repair problem to customer’s satisfaction.” X-Man

6. The X-Man and Mammy Faye Baker The X-Man is an ace relief pitcher and forkball specialist. During off-season periods, X has developed a considerable international reputation as an expert in quality assurance, management, and control. Currently he serves as a senior quality analyst at Mammy Lash, Inc., a company located in Palestine, Texas, and founded by Mammy Faye Baker. Mammy Lash manufactures eye shadow, false eyelashes, and a variety of other eye-related beauty products. Mammy Faye is concerned about the length of the horse hairs used in making eyelashes. Horse hairs were selected as a raw material because they are quite durable, although precision trimming is difficult. Therefore, X decided to sample the trimming process. He took 4 samples of size 3 each with the following results: SampleMeasurements 1 21 23 22 2 20 23 17 3 21 21 21 4 21 20 19 To simplify calculations, the measurements are stated as the number of millimeters above 150. That is, the first measurement is actually 171 millimeters (6.73 inches), the second is 173 millimeters (6.81 inches), and so on. Help the X-Man answer the following questions: 1. Is the trimming process in control? 2. Mammy Faye decides that specifications for eyelash hair length be established. The upper specification limit is 175 millimeters, with a lower specification limit of 165. Is the trimming process capable? X-Man

7. The X-Man and the Vampire The alert student will recall that the X-Man took an off-season job as quality analyst at Mammy Lash, Inc., a manufacturer of eye-related beauty products. X is faced with another serious quality problem, this time involving Mammy Lash’s “Vampire Bat” eye shadow, which most consumers purchase in the personal size (by the barrel). Each barrel should contain approximately 55 pounds of eye shadow. Mammy Faye Baker is concerned about variation in actual weights of barrel contents. X weighed 5 samples, each containing 4 barrels. He found that the mean of the sample means was 54.4 pounds, while the mean of the sample ranges was 3.2 pounds. Help the X-Man answer Mammy Faye’s questions: 1. What are the 3-standard-deviation control limits for the sample means and ranges? 2. What percentage of sample means should fall inside the 3-standard-deviation control limits, if the process is actually in control? What percentage should fall outside the limits? 3. What is the range of expected natural or common-cause variation for individual observations? 4. What percentage of individual observations should fall inside the range of natural or common-cause variation? What percentage should fall outside the limits? 5. Mammy Faye would like to have 2-standard-deviation limits for means and ranges to provide tighter control. What are the revised control limits for means and ranges of samples of size 4? X-Man

8. The X-Man and Roberto Alomar The X-Man became increasingly unhappy in his off-season job at Mammy Lash, Inc. The last straw was a memo from Mammy Faye Baker stating that all employees must report to work each day wearing a complete collection of Mammy Lash products. X moved back to Missouri City, Texas, where he took a job as Senior Vice President for Quality Assurance and Control at Wildflour Pizza. The alert student will recall that Wildflour customers sometimes complain that pizzas are delivered in a partially-eaten condition. Wildflour’s CEO, Terry Collins, asked X to analyze this problem. X collected data for deliveries during the first 5 days of November: # complaints that Sample #Driver # deliveredpizza is partially eaten 1 Roberto Alomar 1,000 4 2 Orlando Miller 300 1 3 Roberto Alomar 1,500 14 4 Orlando Miller 1,000 0 5 Roberto Alomar 100 3 Help the X-Man answer the following questions: 1. What type of control chart should be used to monitor these complaints? 2. Compute upper and lower control limits for the chart that you selected in question 1. 3. Is the process in control? Why or why not? 4. What assumptions about the data are necessary to use your chart? X-Man

9. The X-Man and the Alligator The alert student will recall that the X-Man took a position as Senior Vice President for Quality Assurance and Control at Wildflour Pizza, Missouri City, Texas. X’s first project at Wildflour was an investigation of customer complaints about partially-eaten pizzas. X solved that problem by suspending the culprit, Roberto Alomar, for five days. Although Roberto’s union, the Pizza Teamsters, requested that the suspension be served during the off-season next year, X did not give in and Roberto served his sentence. Another quality problem has cropped up at Wildflour. The CEO, Larry Dierker (who replaced Terry Collins at both Wildflour and the Astros), built a Cajun Sushi Bar at Wildflour’s main restaurant location on Murphy Road, near Highway 6. The Bar proved to be wildly popular, primarily due to its Alligator Sushi, composed of paper-thin slices of fresh alligator marinated in corn liquor. To ensure freshness of the product, Wildflour receives one live alligator each day from its supplier in Hope, Arkansas. Alligator processing is a spectator sport at Wildflour. When each alligator arrives, it is thrown into a pit in the center of the restaurant. Accompanied by applause and cheers from customers, the executive chef, Danny Darwin, dives into the pit and wrestles the alligator into submission. At this point, Danny takes a much-needed shower while his assistant, John Cangelosi, takes over. John slays the beast, dresses it, and slices it. The last step in processing is a good dousing in corn liquor. Danny is concerned about the consistency of the dressed weights of alligators. He would like to receive alligators with dressed weights in a reasonable range of variation around 500 pounds, the Bar’s average daily demand. Weights much above 500 pounds result in wasted sushi, which cannot be retained overnight or it will lose its flavor. Weights much less than 500 pounds result in hungry customers that cannot be served. X-Man

10. The X-Man and the Alligator (cont.) Danny asked X to set up a control chart to monitor the daily dressed weights of alligators. Here are the weights collected by X for five consecutive days: DayDressed weight (lbs.) 1 495 2 517 3 488 4 505 5 541 Help the X-Man answer the following questions: 1. What type of control chart is appropriate for this data? 2. What are the upper and lower control limits? 3. Is the process in control? Why or why not? X-Man

11. The X-Man and Marvin Zindler Marvin Zindler paid a surprise visit to Wildflour’s Cajun Sushi Bar. Although Marvin liked the Gator Sushi, he was quite upset when he found slime in the ice machine. During his Channel 13 broadcast, Marvin became so agitated that his wig flew off. Wildflour’s owner, Drayton McClain, saw Marvin’s broadcast. He called the X-Man into his office, read him the riot act, and ordered him to design a quality inspection program for the company’s nationwide chain of 5,675 restaurant units. Drayton also demanded a control chart to monitor inspection results. X decided to randomly select restaurant units for surprise inspections. Any quality problem in sanitation, restaurant design, equipment, food preparation, training, delivery, or customer service would be counted as a defect. Thus there were an extremely large number of opportunities for defects in any restaurant unit. Here are the results of X’s inspection program for the first 5 days: Number ofNumber of Dayrestaurant unitsquality defects 1 1 6 2 1 3 3 1 5 4 1 2 5 1 5 Help the X-Man answer the following questions: 1. What type of control chart is appropriate for this data? 2. Compute upper and lower control limits. 3. Is the process in control? Why or why not? 4. What assumptions are necessary to use your chart? X-Man

12. The X-Man and Marvin Zindler (cont.) Drayton was unhappy with the pace of X’s inspection program and told him to speed it up. Here are the results for the next 2 days: Number ofNumber of Day restaurant unitsquality defects 6 2 10 7 4 23 Add the new data to the previous sample and help the X-Man answer the following questions: 1. What type of control chart is appropriate for the combined data set (days 1-7)? 2. Compute upper and lower control limits for the combined data set. 3. Is the process in control? Why or why not? X-Man

13. The X-Man and the Moonshine Saki The most popular cocktail served in Wildflour’s Cajun Sushi Bar is Moonshine Saki. According to Billy Wagner, the Houston Chronicle’s wine critic, Moonshine Saki is an audacious, “uniquely Cajun” interpretation of the original Japanese rice wine. Moonshine Saki is actually a blend, composed of fermented rice and pinto beans in a corn liquor base. The drink is served very warm, in a pint Mason jar, with a pinch of roux, a cayenne pepper floating on top, and sporting a green onion swizzle-stick. (Wagner recommends adding a shot of Tabasco to enhance the bouquet.) Drayton asked X to develop a control chart to monitor quarterly sales of Moonshine Saki. The table below shows sales in thousands of gallons for the last two years: YearQtr.Sales (000s) 1995 1 16 2 19 3 24 4 22 1996 1 17 2 21 3 23 4 21 Help the X-Man perform the following tasks: 1. Perform a seasonal adjustment of the data. 2. Use the seasonally-adjusted data to develop a control chart. 3. Interpret the behavior of the seasonally-adjusted data. 4. State the assumptions necessary to use your chart. X-Man