This information is really four Key Performance Indicators all rolled in to one. They assess your total units in stock and separate them into age categories expressed as a percentage.
Example:
A) Units between 01-30 Days = 36 - 60% B) Units between 31-60 Days = 15 - 25% C) Units between 61-90 Days = 6 - 10% D) Units over 90 Days = 3 - 5% E) Total Units in Stock = 60 - 100%
Discussion:
This example shows that 5% of the units that are in stock are over 90 days old. What it does not tell you is how much older than 90 days they are.