The goal is to gather all completed tasks who record type is Implementation Worklog. For example, say I have 3 tasks that are of the type 'Troubleshooting' and each task has a number of hours associated with each task. (i.e. Task 1 6hrs troubleshooting, Task 2 5hrs troubleshooting, Task 3 2hrs torubleshooting.) . I want to sum up the tasks so 14 hours and put the sum into a field on the parent record, which I believe I am doing in the code below. The issue is that not all appropriate parent records are being aggregated correctly. When I check Apex Jobs, it says only 9 jobs have ran when executing anonymous.

global class ProServAutomationBatch implements Database.Batchable<SObject>, Schedulable, Database.Stateful{

Id TaskLogRecordTypeId = Schema.SObjectType.Task.getRecordTypeInfosByName().get('Implementation Worklog').getRecordTypeId();
String comp = 'Completed';

private static Map<Id, Decimal> proServ_HoursSpent = new Map<Id, Decimal>();
private static Map<Id, Decimal> onBoarding_HoursSpent = new Map<Id, Decimal>();
private static Map<Id, Decimal> troubleShooting_HoursSpent = new Map<Id, Decimal>();
private static Map<Id, Decimal> internal_HoursSpent = new Map<Id, Decimal>();


Decimal proServ_currentHoursSpent; 
Decimal onBoarding_currentHoursSpent; 
Decimal troubleShooting_currentHoursSpent;
Decimal internal_currentHoursSpent;

 Decimal proServ_hoursPerProject = 0;
    Decimal totalProServ = 0;
//Decimal proServ_HoursSpent;
//Decimal onBoarding_HoursSpent;
//Decimal troubleShooting_HoursSpent;
//Decimal internal_HoursSpent;
//Set<Id> impProjectIds = new Set<Id>();

global Database.QueryLocator start(Database.BatchableContext BC){ //Queries for all Task whose status is completed and where the Task record type is Implementation Worklog
//return Database.getQueryLocator([SELECT ProServ_Hours_Spent__c, WhatId, Implementation_Type__c FROM Task WHERE Status = :comp AND WhatId IN :implementationProjectToTask.keySet() AND RecordTypeId = :TaskLogRecordTypeId]);
return Database.getQueryLocator([SELECT ProServ_Hours_Spent__c, WhatId, Implementation_Type__c FROM Task WHERE Status = :comp AND RecordTypeId = :TaskLogRecordTypeId ORDER BY WhatId]);
}

// Execute Logic
global void execute(Database.BatchableContext BC, List<Task> workLogTasks){


    Set<Id> impProjectIds = new Set<Id>();
    List<Implementation_Project__c> iP = [SELECT ProServ_Hours_Spent__c,Implementation_Hours_Spent__c, Troubleshooting_Hours__c,Internal_Project_Hours_Spent__c FROM Implementation_Project__c WHERE id in :impProjectIds];
    for(Task t : workLogTasks){
        Decimal hoursTotal = proServ_HoursSpent.get(t.WhatId) == null ? 0 :  proServ_HoursSpent.get(t.WhatId);
        Decimal hoursTotal2 = troubleShooting_HoursSpent.get(t.WhatId) == null ? 0 :  troubleShooting_HoursSpent.get(t.WhatId);
        Decimal hoursTotal3 = onBoarding_HoursSpent.get(t.WhatId) == null ? 0 :  onBoarding_HoursSpent.get(t.WhatId);
        Decimal hoursTotal4 = internal_HoursSpent.get(t.WhatId) == null ? 0 :  internal_HoursSpent.get(t.WhatId);
        if(t.Implementation_Type__c == 'ProServ')
        {   
            proServ_currentHoursSpent = t.ProServ_Hours_Spent__c;
            //impProjectIds.add(t.WhatId);
            if (proServ_HoursSpent != null){
                proServ_HoursSpent.put(t.WhatId, hoursTotal + proServ_currenthoursSpent);
                System.debug('ProServ:' + proServ_HoursSpent);
            }
            impProjectIds.add(t.WhatId);
        }


         //System.debug('ProServ:' + proServ_currentHoursSpent);

        if(t.Implementation_Type__c == 'Troubleshooting')
        {
            troubleShooting_currentHoursSpent = t.ProServ_Hours_Spent__c;
            //impProjectIds.add(t.WhatId);
            if (troubleShooting_HoursSpent != null){
                troubleShooting_HoursSpent.put(t.WhatId, hoursTotal2 + troubleShooting_currentHoursSpent);
            }
            impProjectIds.add(t.WhatId);
        }

        System.debug('TroubleShooting:' + troubleShooting_HoursSpent);

        if(t.Implementation_Type__c == 'Onboarding')
        {
            onBoarding_currentHoursSpent = t.ProServ_Hours_Spent__c;
            //impProjectIds.add(t.WhatId);
             if (onBoarding_HoursSpent != null){
                onBoarding_HoursSpent.put(t.WhatId, hoursTotal3 + onBoarding_currentHoursSpent);
            }
            impProjectIds.add(t.WhatId);
        }
        System.debug('Onboarding:' + onBoarding_HoursSpent);

        if(t.Implementation_Type__c == 'Internal')
        {
            internal_currentHoursSpent = t.ProServ_Hours_Spent__c;
            //impProjectIds.add(t.WhatId);
             if (internal_HoursSpent != null){
                internal_HoursSpent.put(t.WhatId, hoursTotal4 + internal_currentHoursSpent);
            }  
            impProjectIds.add(t.WhatId);
        }
        System.debug('Internal:' + internal_HoursSpent);
    }


    for(Implementation_Project__c impProject : iP){

            impProject.ProServ_Hours_Spent__c = NULL;
            impProject.Implementation_Hours_Spent__c = NULL;
            impProject.Troubleshooting_Hours__c = NULL;
            impProject.Internal_Project_Hours_Spent__c = NULL;

            impProject.ProServ_Hours_Spent__c = proServ_HoursSpent.get(impProject.Id);
            impProject.Implementation_Hours_Spent__c = onBoarding_HoursSpent.get(impProject.Id);
            impProject.Troubleshooting_Hours__c = troubleShooting_HoursSpent.get(impProject.Id);
            impProject.Internal_Project_Hours_Spent__c = internal_HoursSpent.get(impProject.Id);

            //System.debug('Internal' + internal_currentHoursSpent);
            System.debug('ProServ' + proServ_currentHoursSpent);
            //System.debug('Onboarding' + onBoarding_currentHoursSpent);
            //System.debug('Troubleshooting' + troubleShooting_currentHoursSpent);


    }
    Database.update(iP, false);
}

global void execute(SchedulableContext sc){

}

   global void finish(Database.BatchableContext BC){
        // Logic to be Executed at finish
   }
}