1. What do control limits represent? What do specification limits represent? Describe the three cases that compare specification limits to control limits.
2. Describe the relationship between averages and individuals in terms of specification limits and control limits.
3. Why can a process be in control but not be capable of meeting specifications?
4. A hospital is using and R charts to record the time it takes to process patient account information. A sample of five applications is taken each day. The first four weeks' (20 days') data give the following values: If the upper and lower specifications are 21 minutes and 13 minutes, respectively, calculate and Interpret the indices.
5. Two television manufacturers operate plants with differing quality philosophies. One plant works to target and the other works to specification limit. Describe the difference between these two philosophies.
6. Stress tests are used to study the heart muscle after a person has had a heart attack. Timely information from these stress tests can help doctors prevent future heart attacks. The team investigating the turnaround time of stress tests has managed to reduce the amount of time it takes for a doctor to receive the results of a stress test from 68 to 32 hours on average. The team had a goal of reducing test turnaround times to between 30 and 36 hours. Given that the new average test turnaround time is 32 hours, with a standard deviation of 1, and calculate and interpret and 9. Hotels use statistical information and control charts to track their performance on a variety of indicators. Recently a hotel manager has been asked whether his team is capable of maintaining scores between 8 and 10 (on a scale of 1 to 10) for "overall cleanliness of room." The most recent data have a mean of 8.624 and a standard deviation of 1.446. Calculate and interpret the Cpk.