[SalesForce] Process Builder is not validating through change set

I have a process builder which perform apex invocable action. Its working fine in dev sandbox and this are the components I have built:
1. Process Builder
2. Apex Invocable class (ProcessBuilderClass)
3. Associated test class (ProcessBuilderClass_Test)

When I run my test class in Dev sandbox, all test methods are pass. But, when I try to deploy to QA sandbox through change set where I include above components and when I validate by running my test class, it got failed.

Just for reference, here is my code:

Process Builder: My Process builder criteria: Whenever recordtype/stagename/ownerId of opportunity changes, it will call apex class. Which will update time stamp field on opportunity. And its active only
Here is my class code:

public class TestTimeStampUpdate {   
@InvocableMethod
public static void UpdateTimeStamp(List<Id> opptyIds)
{
    List<Opportunity> oppList = new List<Opportunity>();
    for(Id oppId : opptyIds) {
        Opportunity opp = new Opportunity();
        opp.Id = oppId;
        opp.TestField__c = DateTime.now().getTime();
        oppList.add(opp);
    }
    if(!oppList.isEmpty()) {              
        update oppList;
    }
}    

}

Here are my test methods that are pass in dev sandbox, but not while deploying to QA:

@isTest
private class TestTimeStampUpdate_Test {
    static testMethod void TestMethod2() {
        test.startTest();
        Opportunity opp = getOpportunity(); // Insert and return opportuntiy
        opp.StageName = '2 - StageII';
        Decimal testTS = opp.TestField__c;
        update opp;        
        Opportunity oppRec = [SELECT id,TestField__c FROM Opportunity WHERE Id =: opp.Id];
        System.assert(oppRec.TestField__c > testTS);
        test.stopTest();
    }    
    static testMethod void TestMethod1() {
        test.startTest();
        Opportunity opp = getOpportunity();
        Decimal testTS = opp.TestField__c;        
        User usr = getUser();
        opp.OwnerId = usr.Id;
        update opp;        
        Opportunity oppRec = [SELECT id,TestField__c FROM Opportunity WHERE Id =: opp.Id];
        System.assert(oppRec.TestField__c > testTS);
        test.stopTest();
    } 
}

Please help me out where I am missing ?
I really appreciate for your help.