text: The capacity that is billed at the end of the quarter is a total of 39 TB-months in this example. 
  
  The usage data that is collected by Storage Insights is used by IBM to determine the physical 
  data that is provisioned in the system. This data is compared to the base system capacity 
  subscription, and any provisioned capacity beyond that base subscription is billed per 
  terabyte, per month, on a quarterly basis. The calculated usage is based on the average use 
  over a specific month. 
  
  In a highly variable environment, such as managed or cloud service providers, this feature 
  enables the system to be used only as much as is necessary during each month. Usage 
  might increase or decrease, and is billed accordingly. Provisioned capacity is considered 
  capacity that is reserved by the system. 