Using Run Charts to Examine Process Stability All processes illustrate some variation (in qual- ity, conformance to specification, etc.). One hallmark of a quality process is stability. As noted in the text, both control charts and run charts (as well as histograms) can be used to examine process stability. In this exercise you are provided with some information regarding loan processing times at a bank (for an individual loan officer) over a 20-day period. In sequential order, these data are as follows: 90, 73, 62, 88, 47, 68, 87, 68, 50, 69, 26, 78, 80, 30, 32, 73, 60, 50, 36, and 89.
Required
1. Use Excel to plot the above data, in time-series fashion.
2. What is meant by the term process stability?
3. What techniques might you use to support a conclusion as to whether or not this process is stable?