This model illustrates the use of an explicit Cost Period for a resource cost. Running costs such as Maintenance Cost or Rental Cost can be defined for a period other than a year (e.g., quarter, month), so it is not necessary to calculate annual cost if a different period would be more appropriate for the inputs. The results show the Installed and Used Capacities of a resource, and the corresponding Rental Cost for a model running in Months, Quarters and Years.