What is the difference between the absolute and common availability?
Absolute availability is a mathematically exact number – there’s the number of dropouts (during a time period) and the number of monitored times. If they’re mutually divided we get the value of the availability during the whole time period. Common availability comes out of the absolute availability but takes some things into consideration – gives them various importances: • When has the data changed: dropouts (and all data) are less important the older they are. Today’s values are of the most importance (1), those monitored half a year ago 2 times less important (0,5), the ones monitored three quarters of a year ago are 4 times less important (0,25), finally the ones older than a year are of no importance at all. Shortly this month’s data is more important than the one that is almost a year old, the course is fluent, linear. • Availability during the night hours: data monitored between the 2nd and the 6th night hour (every address can change the time) are of half importance than other
