Define an Aggregate Expression
An Aggregate Expression is an Expression that calculates an Expression against child data in a Relationship (example: Counting the number of Incidents linked to a Problem).
To define an Aggregate Expression:
- Create an Expression.
 - In the Editor drop-down, select 
        Aggregate. 
        
The Aggregate Expression section opens.
 - Define the Expression: 
        
- In the Relationship drop-down, select a 
            Relationship 
            (example: Problem Has Linked Incidents). 
            Note: Available Relationships are based on the associated Business Object (example: Problem).
 - In the Function drop-down, select the 
            type of data you want to retrieve: 
            
- Count: Number of Relationship occurrences (example: Number of linked Incidents).
 - Total: Sum of a specified Numerical Expression.
 - Average: Average of a specified Numerical Expression.
 - Maximum: Highest returned value of a specified Numerical Expression.
 - Minimum: Lowest returned value of a specified Numerical Expression.
 
 - In the Apply Against drop-down 
            Token Selector,
            select the 
            Field or 
            Numerical Expression for which you want
            to apply the Expression. This option is available for Total, Average, Maximum,
            Minimum functions. 
            Tip: Create a Custom Expression on-the-fly by clicking New Custom Expression in the Token Selector.
 - (Optional) Limit the returned data using an additional
            Expression: 
            
- Select the 
                Limit check box. 
                
The Limit fields become active.
 - Select an Expression: 
                
- Stored Expression: Click the 
                    Ellipses button 
                    
 to open the Expression Manager, and then
                    select an existing stored Expression or create a new stored Expression. Stored
                    Expressions can be reused in numerous places in 
                    CSM. 
                   - Custom Expression: Click the 
                    Custom Expression button 
                    
 to open the Custom Expression Builder, and
                    then create a custom Expression specifically for this scenario. 
                    Note: Unlike Stored Expressions, Custom Expressions are created on-the-fly, only used where they are created, and not saved in the Expressions Manager. 
 - Stored Expression: Click the 
                    Ellipses button 
                    
 
 - Select the 
                Limit check box. 
                
 
 - In the Relationship drop-down, select a 
            Relationship 
            (example: Problem Has Linked Incidents). 
            
 -  
        
Click OK.
 
