Case Part A: Tesla's Quality Challenge When Tesla announced the release of its new Model 3 electric car, over 276,000 people from around the world put down $1,000 reservations for the car within three days. The innovative new car is a follow-up to the much more expensive Model S and Model X cars. Tesla, led by Elon Musk, the brilliant CEO of the company, now sells over 500,000 cars a year. The company will soon introduce the Cybertruck, another innovative product. The fledgling Palo Alto, California, automaker has struggled with ramping up manufacturing when new vehicles are introduced. Consider the problems that Tesla had with the Model X sport utility vehicle when it was introduced. The company reported that there were many sourcing changes made late in the process of planning production. Tesla tends to make items, such as the middle seats in the Model X, inhouse rather than outsourcing them, which is done by many car manufacturers. The issues associated with the production of the cars are a complex combination of mechanical and computer software problems. Popular features of the cars include drivingassist autopilot functions, auto-parallel parking, and auto-braking. The cars even have an auto-summons feature that lets a driver park and retrieve their car with no one inside. Many post-production issues have been addressed through software updates downloaded to customers over wireless connections. Other mechanical problems are more difficult to resolve. Owners have complained that the Model X falcon-wing doors will not open. When owners have problems like this, Tesla typically schedules a time to pick up the car for repair and leaves a loaner for use by the customer. Another recent issue was a latch on the third-row seat that could come undone during a collision. Tesla decided to recall 2,700ModelX cars to replace the latehes with a new design. This recall totally overloaded Tesla's service outlets with waits of more than two weeks to make the repair. Some customers were offered rental cars due to the long wait. The fledgling Palo Alto, California, automaker has struggled with ramping up manufacturing when new vehicles are introduced. Consider the problems that Tesla had with the Model X sport utility vehicle when it was introduced. The company reported that there were many soureing changes made late in the process of planning production. Tesla tends to make items, such as the middle seats in the Model X, inhouse rather than outsourcing them, which is done by many car manufacturers. The issues associated with the production of the cars are a complex combination of mechanical and computer software problems. Popular features of the cars include drivingassist autopilot functions, auto-parallel parking, and auto-braking. The cars even have an autosummons feature that lets a driver park and retrieve their car with no one inside. Many post-production issues have been addressed throuzh software updates downloaded to customers over wireless connections. Other mechanical problems are more difficult to resolve. Owners have complained that the Model X falconwing doors will not open. When owners have problems like this, Tesla typically schedules a time to pick up the car for repair and leaves a loaner for use by the customer. Another recent issue was a latch on the third-row seat that could come undone during a collision. Tesla decided to recall 2,700 Model X cars to replace the latches with a new design. This recall totally overloaded Tesla's service outlets with waits of more than two weeks to make the repair. Some customers were offered rental cars due to the long wait. So far, customers expect the "white glove" treatment that Tesla currently offers, but a big concern is what Tesla will do when there are miltions of vehicles on the road. Mr. Musk's Tesla cars have many loyal customers, even though problems have been encountered, But moving from hundreds of thousands of vehicles to millions may be dificult, unless some major service improvements are made. Case Part B: Quality Control Analytics As part of the process for improving the quality of their cars. ensincers huve ideatieled a potentiar impronement to the process that makes a washer that is used in the acceletator assembly. The folerances on the thickness of the washer are fairly large sibce the fit can be loose, but if it does happen to get too large, it can cause the aecelerator to bind and create a potential probkm for the driver. (Now This part of the case has been fabricated for teaching purposes.) Let's assume that as a first step to improving the process, a sample of 40 washers coming from the machine that produses the washen was taken and the thickness measured in millimeters. The following table has the measurements from tho fample: 1.92.01.91.82.21.72.01.91.7.1.8 1.82.22.12.21.91.8211.61.81.6 2.12.42.22.12.12.01.81.71.91.9 21.2.02.41.722201.62.02.12.2 Questions 1. If the specification is euch that no washer should bo greater than 2.4 millimeters, assuming that tbe thicknesses are distributed normally. what fraction of the output is expected to be greater than this thickness? 2. If there are upper and lower specifications, where the upper thickness limit is 2,4 abd the lower thickness limit is 1.4, what inaction of the output is expected to be out of tolerance? 3. What is the Ck for the process? 4. What would be the Cpk for the process if it were centered between the specification limits (assane the process standard seviation is the same)? what fraction of the output is expected to be greater than this thickness? 2. If there are upper and lower specifications, where the upper thickness limit is 2.4 and the lower thickness limit is 1.4, what fraction output is expected to be out of tolerance? 3. What is the Cpk for the process? 4. What would be the Cpk for the process if it were centered between the speciffeation limits (assume the process standard deviation i same)? 5. What percentage of output would be expected to be out of tolerance if the process were centered? 6. Set up X and range control charts for the current process. Assume the operators will take samples of 10 washers at a time. 7. Plot the data on your control charts. Does the current process appear to be in control? 8. If the process could be improved so that the standard deviation were only about 0.10 millimeter, what would be the best that could expected with the processes relative to the fraction defective