I have this code below - After inserting a new record, the values are getting overridden with another value as an after update is fired as soon as an after insert operation is complete.

 

trigger TPI_Update_MCCP_Prod_GoalEdit_on_MCCP on MC_Cycle_Plan_Product_vod__c (after update, after insert) {
    
    set<Id> prod_id=new set<Id>();
    set<Id> channel_id=new set<Id>();
    List<Id> target_id=new List<Id>();
    set<Id> target_id2=new set<Id>();   
    set<Id> plan_id=new set<Id>();
    set<Id> channel_id1=new set<Id>();
    set<Id> prod_id1=new set<Id>();
    decimal before_val;
    decimal after_val;
    string prod_name;
    AggregateResult[] groupedResults;
    integer aggregated_goal_val;
    decimal old_goal_val;
    decimal new_goal_val;
    set<Id> sum = new Set<Id>();
    boolean flag;
   
    List<MC_Cycle_Plan_vod__c> mcptoUpdate = New List<MC_Cycle_Plan_vod__c>();
    //    
    //hold value of products edited in set 'prod_id'
    //    
    for (MC_Cycle_Plan_Product_vod__c p: trigger.new)
    {      
        if(trigger.isInsert)
        {
            prod_name = Trigger.newMap.get(p.id).Product_Name_vod__c;          
            new_goal_val = Trigger.newMap.get(p.Id).Product_Activity_Goal_vod__c;  
            flag = true;
        }
        else if(trigger.isUpdate){
            old_goal_val = Trigger.oldMap.get(p.Id).Product_Activity_Goal_vod__c;
            prod_name = Trigger.oldMap.get(p.id).Product_Name_vod__c;
            new_goal_val = Trigger.newMap.get(p.Id).Product_Activity_Goal_vod__c;
            flag=false;
        }
        //        
        prod_id.add(p.id);        
        //      
        system.debug('MCCP product - ' + prod_id);
        System.debug('Old value of MCCP product - '+old_goal_val);
        //
        //hold values of channels related to products in set 'channel_id' where channel is 'Interaction'
        //      
        if(p.Channel_vod__c=='Interaction')
        {
            channel_id.add(p.Cycle_Plan_Channel_vod__c);
            system.debug('MCCP channel - ' + channel_id); 
        }
        //
        //hold values of target in 'target_id'
        //       
        List<MC_Cycle_Plan_Channel_vod__c> t= [select Cycle_Plan_Target_vod__c from MC_Cycle_Plan_Channel_vod__c where Id IN: channel_id];
        for (MC_Cycle_Plan_Channel_vod__c mc : t)
        {
            target_id.add(mc.Cycle_Plan_Target_vod__c);
        }
        system.debug('MCCP Target - ' + target_id);
        //
        //hold values of plan in 'plan_id'
        //      
        List<MC_Cycle_Plan_Target_vod__c> t2 = [select id,Cycle_Plan_vod__r.id from MC_Cycle_Plan_Target_vod__c where  Id IN : target_id];        
        for (MC_Cycle_Plan_Target_vod__c mc2 : t2)
        {
            plan_id.add(mc2.Cycle_Plan_vod__r.id);  
        }
        system.debug('MC Cycle Plan - ' + plan_id); 
        //
        //hold values of all target in 'target_id2'
        // 
        List<MC_Cycle_Plan_Target_vod__c> plan_1 = [select id from MC_Cycle_Plan_Target_vod__c where Cycle_Plan_vod__c in : plan_id];        
        for (MC_Cycle_Plan_Target_vod__c mc3 : plan_1)
        {
            target_id2.add(mc3.id);  
        }
        //
        //hold values of all channels of above targets where channel is 'Interaction' in 'channel_id1'
        // 
        system.debug('All MCCP Targets of above MC Cycle Plan - ' + target_id2);         
        List<MC_Cycle_Plan_Channel_vod__c> t3 = [select id,Channel_vod__c from MC_Cycle_Plan_Channel_vod__c where  Cycle_Plan_Target_vod__c IN : target_id2];       
        for (MC_Cycle_Plan_Channel_vod__c mc4 : t3)
        {
            if(mc4.Channel_vod__c=='Interaction'){
                channel_id1.add(mc4.id);  
            }            
        }
        system.debug('All MCCP Channels of above MCCP Target - ' + channel_id1);
        //    
        //hold value of products edited in set 'prod_id'
        //        
        List<MC_Cycle_Plan_Product_vod__c>  p1  = [select id,Product_Activity_Goal_vod__c from MC_Cycle_Plan_Product_vod__c where Cycle_Plan_Channel_vod__c in : channel_id1];
        
        for (MC_Cycle_Plan_Product_vod__c mc5 : p1)
        {
            prod_id1.add(mc5.id);
        }       
        system.debug('All MCCP Products of above MCCP Channels - '+ prod_id1);
        Set<id> result = prod_id1.clone();       
        system.debug('Removing the product where the value of goal is changed - ' + result.removeall(prod_id));
        system.debug('Resulting set of products where goal is not changed -'+result);
        List<MC_Cycle_Plan_Product_vod__c> mcp1 =[select Product_Name_vod__c from MC_Cycle_Plan_Product_vod__c where Id in: result];
        System.debug(mcp1.size());        
        //
        //     Aggregation of goals grouped by product with no change is stored in 'groupedResults'   
        //                               
        for(MC_Cycle_Plan_Product_vod__c aq : mcp1)
        {        
            if(aq.Product_Name_vod__c ==prod_name)
            {
                sum.add(aq.id);                
            }
        }    
        System.debug('Sum'+sum);
        groupedResults = [SELECT SUM(Product_Activity_Goal_vod__c)aver FROM MC_Cycle_Plan_Product_vod__c where Id in : sum]; 
        system.debug('Sum of goals grouped by product with no change - ' + integer.valueOf(groupedResults[0].get('aver')) );       
        //
        // typecasting the result into integer data type (aggregated_goal_val = total of all goals which are not edited)
        //         
        aggregated_goal_val  = integer.valueOf(groupedResults[0].get('aver')); 
        System.debug('Aggregated_goal_val in Insert - '+aggregated_goal_val);
        //
        //Old sum of goals (edited and non edited) grouped by product
        //
        system.debug('xxx'+trigger.isInsert);
        system.debug('xxx'+trigger.isUpdate);
        if(flag)
        {          
            before_val = aggregated_goal_val; 
            System.debug('Before Value in Insert - '+before_val);
            System.debug('Aggregated_goal_val in Insert - '+aggregated_goal_val);
        }
        else
        {
            before_val = aggregated_goal_val + old_goal_val;
            system.debug('Old value of edit goals -'+before_val);
        }
        //
        //New sum of goals (edited and non edited) grouped by product
        //
        after_val= aggregated_goal_val + new_goal_val;
        system.debug('New value of edit goals -'+after_val);
    }   
    List<MC_Cycle_Plan_vod__c> mcp =[select Product_1_TPI__c,Product_2_TPI__c,Product_3_TPI__c,Product_4_TPI__c,HQ_Target_1_TPI__c,HQ_Target_2_TPI__c,HQ_Target_3_TPI__c,HQ_Target_4_TPI__c,Proposed_Target_1_TPI__c,Proposed_Target_2_TPI__c,Proposed_Target_3_TPI__c,Proposed_Target_4_TPI__c from MC_Cycle_Plan_vod__c Where Id IN :plan_id];       
    for(MC_Cycle_Plan_vod__c mc:mcp){     
        for(MC_Cycle_Plan_Product_vod__c cyclprod : [Select Product_Name_vod__c from MC_Cycle_Plan_Product_vod__c WHERE ID =:prod_id]){                       
            if (mc.Product_1_TPI__c ==  ''){
                System.debug('Inserting in 1st prod');
                mc.Product_1_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_1_TPI__c = before_val;
                mc.Proposed_Target_1_TPI__c = after_val;
            }
            else if (mc.Product_1_TPI__c != '' && mc.Product_1_TPI__c == cyclprod.Product_Name_vod__c) 
            {
                System.debug('Updating in 1st prod');
                mc.Product_1_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_1_TPI__c = before_val;
                mc.Proposed_Target_1_TPI__c = after_val;
                system.debug('satisfy 1');
            }               
            else if (mc.Product_2_TPI__c == '')
            {
                System.debug('Inserting in 2nd prod');
                mc.Product_2_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_2_TPI__c = before_val;
                mc.Proposed_Target_2_TPI__c = after_val;
                system.debug('satisfy 2');
            }           
            else if (mc.Product_2_TPI__c != '' && mc.Product_2_TPI__c == cyclprod.Product_Name_vod__c)
            {
                System.debug('Updating in 2nd prod');         
                mc.Product_2_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_2_TPI__c = before_val;
                mc.Proposed_Target_2_TPI__c = after_val;
            }           
            else if (mc.Product_3_TPI__c == '')
            {
                System.debug('Inserting in 3rd prod');
                mc.Product_3_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_3_TPI__c = before_val;
                mc.Proposed_Target_3_TPI__c = after_val;                   
            }               
            else if (mc.Product_3_TPI__c != '' && mc.Product_3_TPI__c == cyclprod.Product_Name_vod__c)
            {
                System.debug('Updating in 3rd prod');
                mc.Product_3_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_3_TPI__c = before_val;
                mc.Proposed_Target_3_TPI__c = after_val;
            } 
            
            else if (mc.Product_4_TPI__c == '')
            {
                System.debug('Inserting in 4th prod');
                mc.Product_4_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_4_TPI__c = before_val;
                mc.Proposed_Target_4_TPI__c = after_val;                    
            }   
            else if (mc.Product_4_TPI__c != '' && mc.Product_4_TPI__c == cyclprod.Product_Name_vod__c)
            {
                System.debug('Inserting in 4th prod');
                mc.Product_4_TPI__c = cyclprod.Product_Name_vod__c;
                mc.HQ_Target_4_TPI__c = before_val;
                mc.Proposed_Target_4_TPI__c = after_val;   
            }           
        }
        mcptoUpdate.add(mc);
    }
    try{
        update mcptoUpdate;
        system.debug('\n mc cycle plan after update -> '+mcptoUpdate);
    }
    catch(Exception ex){
        System.debug('\n exception aa => '+ex.getMessage());
    }      
}