[SalesForce] Case Assignment Rules

Here's what I found. There's a link to do this with apex programmatically, and you may need to call the assignmentRuleHeader class in an update trigger.

From a standard UI, a user can trigger assignment rules by simply checking the "Assign using active assignment rules" checkbox under the Optional section. The problem arises when your app needs to insert the Case from Apex and wants to trigger assignment rules. Using this script, a Case will be inserted but assignment rules will not be triggered as there is no such field "Assign using active assignment rules" on Case.

Code can be found here: http://developer.force.com/cookbook/recipe/running-case-assignment-rules-from-apex

https://help.salesforce.com/apex/HTViewSolution?id=000187821&language=en_US

I've taken the liberty of writing a simplified trigger and class with a method (having @future annotation --> rationale found here: Case Assignment Rule workaround). This concept can be extended to a Trigger on the User object, which can call the Case Reassignment method after a User is deactivated. Note, I intentionally did not bulkify the code to better demonstrate the concept.

In my coded example, I created a custom field [Reassign_with_Active_Assignment_Rule__c] (checkbox) to trigger the class to run and invoke the standard Case reassignment functionality.

trigger MyCaseReassignmentTrigger on Case (before update) {

    for(Case c : trigger.new){

        //only run trigger when my business condiions are met and not invoked by an @future method to avoid infinite recursion
        if(c.Reassign_with_Active_Assignment_Rule__c && !System.isFuture()){

            MyCaseReassignmentClass.reassignCaseWithActiveRule(c.Id);            

        }

    }

}




public class MyCaseReassignmentClass {


    /*
     * Pass the ID values to a future method, and perform your ownership changea synchronously.
     * This will allow you to reassign the user correctly after the assignment rule logic has executed.
     * Source: sfdcfox https://salesforce.stackexchange.com/a/40004/15114
     */

    @future
    public static void reassignCaseWithActiveRule(ID myCaseId) {

        //fetching the desired assignment rules on Case...
        AssignmentRule AR = new AssignmentRule();
        AR = [select id from AssignmentRule where SobjectType = 'Case' and Active = true limit 1];

        //recreating the DMLOptions setting for "Assign using active assignment rules" checkbox on Case object...
        Database.DMLOptions dmlOpts = new Database.DMLOptions();
        dmlOpts.assignmentRuleHeader.assignmentRuleId= AR.id;

        //get current instance of sObject (Case)...
        Case myCase = [select Id, Reassign_with_Active_Assignment_Rule__c from Case where Id =: myCaseId limit 1];

        //set DMLOptions on this record so it will be processed suing assignment rules...
        myCase.setOptions(dmlOpts);
        myCase.description = 'processed w/ @future on '+ dateTime.now();

        update myCase; 

    }

}

This can be done in two ways:
1) Using workflows: Make the workflow fire on only when the record is created. set the ownerid of case in the field update

2) in the flow itself you can set the ownerid based on your criteria