18.2. Control Charts

Try these first

1. 1.

   What is the purpose of a control chart?

   Hint

   Think about its visual representation.

2. 2.

   Define common cause variation.

   Hint

   Consider the normal expected performance.

3. 3.

   What distinguishes common cause variation from special cause variation?

   • Common cause is predictable; special cause is not.
   • Common cause is sudden; special cause occurs regularly.
   • Both are similar.

   Hint

   Think about the causes' nature.

4. 4.

   True or False: Control limits are fixed and never change.

   • True
   • False

   Hint

   Consider how data influences the chart.

5. 5.

   Given a set of temperature readings from a manufacturing process over a month, plot a control chart and determine if any readings fall outside control limits. What actions should be taken based on your findings?

   Hint

   Follow the steps for plotting and calculating you learned.

6. 6.

   Imagine a factory reports frequently shifting averages in its production. How would you assess if these shifts are due to common causes or special causes? What steps would you recommend?

   Hint

   Consider the data's historical context and look for patterns.