Aggregate calculations in a parent case type collect run-time data from child case types.
For example, the total time to complete an Accident Claim case can be calculated by adding together the hours logged in each of Vehicle Damage and Bodily Injury cases. By defining parent-child calculations in a case type, you can avoid running manual reports.
An aggregate calculation is implemented in your application as a set of watched properties and one or more declare triggers. The result of the calculation is dynamically updated as each child case is processed.