SPC at the Esquire Club:
Donald J. Wheeler, Kaz Koike
A unique and interesting case study. Another example of how versatile Quality tools are. To us this is one of the best illustrations that the often heard "it can't work here" is most likely an inaccurate statement.
Working with Rare Events
Donald J. Wheeler
"Whenever the average count per time period drops below 1.00 you are working with rare events.
When this happens you should shift from counting the events per time period and instead measure the area of opportunity between the rare events. Here you cease to get a value every time period, and instead get a value every time you have an event."