Merge branch 'develop' into develop-sm-inventory-management

User Story #1955
User Story #1956

**Changes**
* Added `DataStoreLockGuard` class to provide scoped automatic locking and unlocking for the datastore.
* Refactored `Service`, `ServiceBooking`, `JobCard`, and `ComboPackage` models to replace CSV-based serialization with fixed-size `Serialized*` struct records.
* Removed legacy `serialize()`, `deserialize()`, and `getHeaders()` methods from all affected model classes.
* Updated `DataStore` getter methods (`getServices`, `getComboPackages`, `getServiceBookings`, `getJobCards`) to load records from shared memory and automatically enrich them with linked entities (inventory items, services, bookings, users).
* Implemented generic save helpers (`saveServices`, `saveComboPackages`, etc.) using the `saveRecords` template to persist tracked records directly.
* Integrated `DataStoreLockGuard` into critical `ServiceManagementService` methods including `purchaseService`, `purchaseComboPackage`, `createService`, `removeService`, `cancelCustomerServiceBookings`, and `updateJobStatus`.
* Refactored cancellation workflows (`cancelCustomerServiceBookings`, `cancelTechnicianJobs`) to use `TrackedRecord` objects, correctly marking states as `MODIFIED` before persisting changes.
* Updated inventory restoration logic to accept tracked inventory maps and increment quantities while updating record states.
* Modified service layer access patterns to extract `.data` pointers from `TrackedRecord` wrappers instead of accessing raw map values directly.
* Added necessary header dependencies (`DataStoreLockGuard.h`, `SerializedRecords.h`) across data store and service layers.
* Removed redundant manual persistence calls in the service layer, relying on explicit `save*` calls after modifications within locked scopes.

Related work items: #1927, #1955, #1956

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/DataStore.cpp

@@ -12,6 +12,8 @@ Date: 19-May-2026
 #include "Config.h"
 #include "SerializedRecords.h"
 #include "FileHelper.h"
+#include "ServiceBooking.h"
+#include "JobCard.h"
 
 /*
 Function: DataStore
@@ -252,6 +254,28 @@ Returns:
 */
 util::Map<std::string, TrackedRecord<Service>>& DataStore::getServices()
 {
+    util::Map<std::string, TrackedRecord<Service>> services = loadRecords<Service, SerializedService>(m_services);
+    refreshCache(m_serviceCache, services);
+    util::Map<std::string, TrackedRecord<InventoryItem>>& inventoryItems = getInventoryItems();
+    size_t numberOfServices = m_serviceCache.getSize();
+    for (int iteratorOne =0; iteratorOne < numberOfServices; iteratorOne++)
+    {
+        Service* currentService = m_serviceCache.getValueAt(iteratorOne).data;
+        util::Map<std::string, InventoryItem*> inventoryItemMap;
+        util::Vector<std::string> currentServiceInventoryItem = currentService->getRequiredInventoryItemIDs();
+        for (int iteratorTwo = 0; iteratorTwo < currentServiceInventoryItem.getSize(); iteratorTwo++)
+        {
+            const std::string& currentInventoryItemId = currentServiceInventoryItem[iteratorTwo];
+            int currentInventoryItemIndex = inventoryItems.find(currentInventoryItemId);
+            if (currentInventoryItemIndex == -1)
+            {
+                throw std::runtime_error("Invalid inventory item ID");
+            }
+            InventoryItem* currentItem = inventoryItems.getValueAt(currentInventoryItemIndex).data;
+            inventoryItemMap[currentInventoryItemId] = currentItem;
+        }
+        currentService->setRequiredInventoryItems(inventoryItemMap);
+    }
     return m_serviceCache;
 }
 
@@ -265,6 +289,28 @@ Returns:
 */
 util::Map<std::string, TrackedRecord<ComboPackage>>& DataStore::getComboPackages()
 {
+    util::Map<std::string, TrackedRecord<ComboPackage>> comboPackages = loadRecords<ComboPackage, SerializedComboPackage>(m_comboPackages);
+    refreshCache(m_comboPackageCache, comboPackages);
+    util::Map<std::string, TrackedRecord<Service>>& services = getServices();
+    size_t numberOfComboPackages = m_comboPackageCache.getSize();
+    for (int iteratorOne = 0; iteratorOne < numberOfComboPackages; iteratorOne++)
+    {
+        ComboPackage* currentComboPackage =  m_comboPackageCache.getValueAt(iteratorOne).data;
+        util::Vector<std::string> currentServiceIds = currentComboPackage->getServiceIDs();
+        util::Map<std::string, Service*> currentComboPackageServices;
+        for (int iteratorTwo = 0; iteratorTwo < currentServiceIds.getSize(); iteratorTwo++)
+        {
+            const std::string& currentServiceId = currentServiceIds[iteratorTwo];
+            int serviceIndex = services.find(currentServiceId);
+            if (serviceIndex == -1)
+            {
+                throw std::runtime_error("Invalid service ID");
+            }
+            Service* currentService = services.getValueAt(serviceIndex).data;
+            currentComboPackageServices[currentServiceId] = currentService;
+        }
+        currentComboPackage->setServices(currentComboPackageServices);
+    }
     return m_comboPackageCache;
 }
 
@@ -278,6 +324,8 @@ Returns:
 */
 util::Map<std::string, TrackedRecord<InventoryItem>>& DataStore::getInventoryItems()
 {
+    auto inventoryItems = loadRecords<InventoryItem, SerializedInventoryItem>(m_inventoryItems);
+    refreshCache(m_inventoryItemCache, inventoryItems);
     return m_inventoryItemCache;
 }
 
@@ -291,6 +339,49 @@ Returns:
 */
 util::Map<std::string, TrackedRecord<ServiceBooking>>& DataStore::getServiceBookings()
 {
+    util::Map<std::string, TrackedRecord<ServiceBooking>> serviceBookings = loadRecords<ServiceBooking, SerializedServiceBooking>(m_serviceBookings);
+    refreshCache(m_serviceBookingCache, serviceBookings);
+    auto& users = getUsers();
+    auto& services = getServices();
+    size_t numberOfServiceBookings = m_serviceBookingCache.getSize();
+    for (int iteratorOne = 0; iteratorOne < numberOfServiceBookings; iteratorOne++)
+    {
+        ServiceBooking* serviceBooking = m_serviceBookingCache.getValueAt(iteratorOne).data;
+        auto& serviceIds = serviceBooking->getServiceIDs();
+        util::Map<std::string, Service*> servicesInBooking;
+        for (int iteratorTwo = 0; iteratorTwo < serviceIds.getSize(); iteratorTwo++)
+        {
+            const std::string& currentServiceId = serviceIds[iteratorTwo];
+            int serviceIndex = services.find(currentServiceId);
+            if (serviceIndex == -1)
+            {
+                throw std::runtime_error("Invalid service index.");
+            }
+            auto currentService = services.getValueAt(serviceIndex);
+            servicesInBooking[currentServiceId] = currentService.data;
+        }
+        serviceBooking->setServices(servicesInBooking);
+        if (!serviceBooking->getCustomerId().empty())
+        {
+            int userIndex = users.find(serviceBooking->getCustomerId());
+            if (userIndex == -1)
+            {
+                throw std::runtime_error("Invalid user index.");
+            }
+            auto customer = users.getValueAt(userIndex);
+            serviceBooking->setCustomer(customer.data);
+        }
+        if (!serviceBooking->getAssignedTechnicianId().empty())
+        {
+            int technicianIndex = users.find(serviceBooking->getAssignedTechnicianId());
+            if (technicianIndex == -1)
+            {
+                throw std::runtime_error("Invalid technician index.");
+            }
+            auto technician = users.getValueAt(technicianIndex);
+            serviceBooking->setAssignedTechnician(technician.data);
+        }
+    }
     return m_serviceBookingCache;
 }
 
@@ -304,9 +395,51 @@ Returns:
 */
 util::Map<std::string, TrackedRecord<JobCard>>& DataStore::getJobCards()
 {
+    util::Map<std::string, TrackedRecord<JobCard>> jobCards = loadRecords<JobCard, SerializedJobCard>(m_jobCards);
+    refreshCache(m_jobCardCache, jobCards);
+    auto& serviceBookings = getServiceBookings();
+    auto& services = getServices();
+    auto& users = getUsers();
+    int numberOfJobCards = m_jobCardCache.getSize();
+    for (int iterator = 0; iterator < numberOfJobCards; iterator++)
+    {
+        JobCard* jobCard = m_jobCardCache.getValueAt(iterator).data;
+        if (!jobCard)
+        {
+            continue;
+        }
+        const std::string& bookingId = jobCard->getBookingId();
+        int bookingIndex = serviceBookings.find(bookingId);
+        if (bookingIndex == -1)
+        {
+            throw std::runtime_error("Invalid booking ID: " + bookingId);
+        }
+        auto trackedBooking = serviceBookings.getValueAt(bookingIndex);
+        jobCard->setBooking(trackedBooking.data);
+        const std::string& serviceId = jobCard->getServiceId();
+        int serviceIndex = services.find(serviceId);
+        if (serviceIndex == -1)
+        {
+            throw std::runtime_error("Invalid service ID: " + serviceId);
+        }
+        auto trackedService = services.getValueAt(serviceIndex);
+        jobCard->setService(trackedService.data);
+        const std::string& technicianId = jobCard->getTechnicianId();
+        if (!technicianId.empty())
+        {
+            int technicianIndex = users.find(technicianId);
+            if (technicianIndex == -1)
+            {
+                throw std::runtime_error("Invalid technician ID: " + technicianId);
+            }
+            auto trackedTechnician = users.getValueAt(technicianIndex);
+            jobCard->setTechnician(trackedTechnician.data);
+        }
+    }
     return m_jobCardCache;
 }
 
+
 /*
 Function: getInvoices
 Description: Retrieves all invoice records from the datastore.
@@ -426,6 +559,7 @@ Returns:
 */
 void DataStore::saveServices()
 {
+    saveRecords<Service, SerializedService>(m_services, m_serviceCache);
 }
 
 /*
@@ -438,6 +572,7 @@ Returns:
 */
 void DataStore::saveComboPackages()
 {
+    saveRecords<ComboPackage, SerializedComboPackage>(m_comboPackages, m_comboPackageCache);
 }
 
 /*
@@ -450,6 +585,7 @@ Returns:
 */
 void DataStore::saveInventoryItems()
 {
+    saveRecords<InventoryItem, SerializedInventoryItem>(m_inventoryItems, m_inventoryItemCache);
 }
 
 /*
@@ -462,6 +598,7 @@ Returns:
 */
 void DataStore::saveServiceBookings()
 {
+    saveRecords<ServiceBooking, SerializedServiceBooking>(m_serviceBookings, m_serviceBookingCache);
 }
 
 /*
@@ -474,6 +611,7 @@ Returns:
 */
 void DataStore::saveJobCards()
 {
+    saveRecords<JobCard, SerializedJobCard>(m_jobCards, m_jobCardCache);
 }
 
 /*

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/DataStore.h

@@ -11,6 +11,7 @@ Date: 19-May-2026
 #include "Map.h"
 #include "MappingInfo.h"
 #include "TrackedRecord.h"
+#include "SerializedRecords.h"
 #include "SharedMemory.h"
 #include "User.h"
 #include "Notification.h"

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ComboPackage.cpp

@@ -9,6 +9,7 @@ Date: 19-May-2026
 
 #include <sstream>
 #include <stdexcept>
+#include "SerializedRecords.h"
 #include "ComboPackage.h"
 #include "Service.h"
 #include "Factory.h"
@@ -28,7 +29,8 @@ Returns:
 ComboPackage::ComboPackage()
     : m_id("CMP" + std::to_string(++m_uid)),
     m_status(util::State::ACTIVE),
-    m_discountPercentage(0.0) {}
+    m_discountPercentage(0.0) {
+}
 
 /*
 Function: ComboPackage
@@ -270,72 +272,38 @@ static util::Vector<std::string> getServiceIDsAsVector(const std::string& servic
 
 /*
 Function: serialize
-Description: Serializes the combo package into a CSV-formatted string.
+Description: Serializes the ComboPackage object into a SerializedComboPackage record.
 Parameters:
     - None
 Returns:
-    - std::string: Serialized combo package record
+    - SerializedComboPackage: Serialized representation of the combo package
 */
-std::string ComboPackage::serialize() const
+SerializedComboPackage ComboPackage::serialize() const
 {
-    std::ostringstream serializedComboPackage;
-    serializedComboPackage << m_id << ','
-        << m_packageName << ','
-        << m_discountPercentage << ','
-        << getServiceIDsAsString(m_serviceIDs) << ','
-        << util::getStateString(m_status);
-    return serializedComboPackage.str();
+    SerializedComboPackage serialized = {};
+    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    strcpy_s(serialized.packageName, sizeof(serialized.packageName), m_packageName.c_str());
+    strcpy_s(serialized.serviceIDs, sizeof(serialized.serviceIDs), getServiceIDsAsString(m_serviceIDs).c_str());
+    serialized.discountPercentage = m_discountPercentage;
+    serialized.status = m_status;
+    return serialized;
 }
 
 /*
 Function: deserialize
-Description: Deserializes a CSV-formatted string into a ComboPackage object.
+Description: Deserializes a SerializedComboPackage record into a ComboPackage object.
 Parameters:
-    - record: const std::string&, serialized combo package record
+    - serializedComboPackage: const SerializedComboPackage&, serialized combo package record
 Returns:
     - ComboPackage*: Pointer to the deserialized ComboPackage object
-Throws:
-    - std::runtime_error if data is invalid
 */
-ComboPackage* ComboPackage::deserialize(const std::string& record)
+ComboPackage* ComboPackage::deserialize(const SerializedComboPackage& serializedComboPackage)
 {
-    std::string id, packageName;
-    std::string discountPercentageString, serviceIDsString, statusString;
-    double discountPercentage;
-    std::istringstream serializedComboPackage(record);
-    getline(serializedComboPackage, id, ',');
-    getline(serializedComboPackage, packageName, ',');
-    getline(serializedComboPackage, discountPercentageString, ',');
-    getline(serializedComboPackage, serviceIDsString, ',');
-    getline(serializedComboPackage, statusString, ',');
-    try
-    {
-        discountPercentage = std::stod(discountPercentageString);
-    }
-    catch (...)
-    {
-        throw std::runtime_error("Invalid combo package data");
-    }
-    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serviceIDsString);
-    util::State status = util::getState(statusString);
+    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serializedComboPackage.serviceIDs);
     return Factory::getObject<ComboPackage>(
-        id,
-        packageName,
-        discountPercentage,
+        serializedComboPackage.id,
+        serializedComboPackage.packageName,
+        serializedComboPackage.discountPercentage,
         serviceIDs,
-        status
-    );
-}
-
-/*
-Function: getHeaders
-Description: Retrieves the CSV headers for combo package serialization.
-Parameters:
-    - None
-Returns:
-    - std::string: Header string ("ID,PackageName,DiscountPercentage,ServiceIDs,Status")
-*/
-std::string ComboPackage::getHeaders()
-{
-    return "ID,PackageName,DiscountPercentage,ServiceIDs,Status";
-}
+        serializedComboPackage.status);
+}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ComboPackage.h

@@ -39,7 +39,6 @@ public:
     void setDiscountPercentage(double discountPercentage);
     void setServices(const util::Map<std::string, Service*>& services);
     void setState(util::State status);
-    std::string serialize() const;
-    static ComboPackage* deserialize(const std::string&);
-    static std::string getHeaders();
+    SerializedComboPackage serialize() const;
+    static ComboPackage* deserialize(const SerializedComboPackage&);
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/InventoryItem.cpp

@@ -8,6 +8,7 @@ Date: 19-May-2026
 
 #include <sstream>
 #include <stdexcept>
+#include "SerializedRecords.h"
 #include "Factory.h"
 #include "StringHelper.h"
 #include "InventoryItem.h"
@@ -27,7 +28,8 @@ InventoryItem::InventoryItem()
     : m_id("IIM" + std::to_string(++m_uid)),
     m_quantity(0),
     m_status(util::State::ACTIVE),
-    m_price(0.0) {}
+    m_price(0.0) {
+}
 
 /*
 Function: InventoryItem
@@ -45,7 +47,8 @@ InventoryItem::InventoryItem(const std::string& partName, int quantity, double p
     m_partName(partName),
     m_quantity(quantity),
     m_status(util::State::ACTIVE),
-    m_price(price) {}
+    m_price(price) {
+}
 
 /*
 Function: InventoryItem (parameterized constructor with ID)
@@ -206,73 +209,37 @@ void InventoryItem::setState(util::State status)
 
 /*
 Function: serialize
-Description: Serializes the inventory item into a CSV-formatted string.
+Description: Serializes the InventoryItem object into a SerializedInventoryItem record.
 Parameters:
     - None
 Returns:
-    - std::string: Serialized inventory item record
+    - SerializedInventoryItem: Serialized representation of the inventory item
 */
-std::string InventoryItem::serialize() const
+SerializedInventoryItem InventoryItem::serialize() const
 {
-    std::ostringstream serializedInventoryItem;
-    serializedInventoryItem << m_id << ','
-        << m_partName << ','
-        << m_quantity << ','
-        << m_price << ','
-        << util::getStateString(m_status);
-    return serializedInventoryItem.str();
+    SerializedInventoryItem serialized = {};
+    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    strcpy_s(serialized.partName, sizeof(serialized.partName), m_partName.c_str());
+    serialized.quantity = m_quantity;
+    serialized.price = m_price;
+    serialized.status = m_status;
+    return serialized;
 }
 
 /*
 Function: deserialize
-Description: Deserializes a CSV-formatted string into an InventoryItem object.
+Description: Deserializes a SerializedInventoryItem record into an InventoryItem object.
 Parameters:
-    - record: const std::string&, serialized inventory item record
+    - serializedInventoryItem: const SerializedInventoryItem&, serialized inventory item record
 Returns:
     - InventoryItem*: Pointer to the deserialized InventoryItem object
-Throws:
-    - std::runtime_error if data is invalid
 */
-InventoryItem* InventoryItem::deserialize(const std::string& record)
+InventoryItem* InventoryItem::deserialize(const SerializedInventoryItem& serializedInventoryItem)
 {
-    std::string id, partName;
-    std::string quantityString, priceString, statusString;
-    int quantity;
-    double price;
-    std::istringstream serializedInventoryItem(record);
-    getline(serializedInventoryItem, id, ',');
-    getline(serializedInventoryItem, partName, ',');
-    getline(serializedInventoryItem, quantityString, ',');
-    getline(serializedInventoryItem, priceString, ',');
-    getline(serializedInventoryItem, statusString, ',');
-    try
-    {
-        quantity = std::stoi(quantityString);
-        price = std::stod(priceString);
-    }
-    catch (...)
-    {
-        throw std::runtime_error("Invalid inventory item data");
-    }
-    util::State status = util::getState(statusString);
     return Factory::getObject<InventoryItem>(
-        id,
-        partName,
-        quantity,
-        price,
-        status
-    );
-}
-
-/*
-Function: getHeaders
-Description: Retrieves the CSV headers for inventory item serialization.
-Parameters:
-    - None
-Returns:
-    - std::string: Header string ("ID,PartName,Quantity,Price,Status")
-*/
-std::string InventoryItem::getHeaders()
-{
-    return "ID,PartName,Quantity,Price,Status";
+        serializedInventoryItem.id,
+        serializedInventoryItem.partName,
+        serializedInventoryItem.quantity,
+        serializedInventoryItem.price,
+        serializedInventoryItem.status);
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/InventoryItem.h

@@ -6,11 +6,12 @@ Author: Trenser
 Date: 19-May-2026
 */
 
-
 #pragma once
 #include <string>
 #include "Enums.h"
 
+struct SerializedInventoryItem;
+
 class InventoryItem
 {
 private:
@@ -34,7 +35,6 @@ public:
     void setQuantity(int quantity);
     void setPrice(double price);
     void setState(util::State status);
-    std::string serialize() const;
-    static InventoryItem* deserialize(const std::string&);
-    static std::string getHeaders();
+    SerializedInventoryItem serialize() const;
+    static InventoryItem* deserialize(const SerializedInventoryItem&);
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/JobCard.cpp

@@ -9,6 +9,7 @@ Date:19-May-2026
 
 #include <sstream>
 #include <stdexcept>
+#include "SerializedRecords.h"
 #include "JobCard.h"
 #include "Factory.h"
 #include "StringHelper.h"
@@ -28,7 +29,8 @@ JobCard::JobCard()
     m_booking(nullptr),
     m_service(nullptr),
     m_technician(nullptr),
-    m_status(util::ServiceJobStatus()) {}
+    m_status(util::ServiceJobStatus()) {
+}
 
 /*
 Function: JobCard
@@ -65,7 +67,8 @@ JobCard::JobCard(const std::string& bookingId,
     m_technician(technician),
     m_assignedDate(assignedDate),
     m_status(status),
-    m_completionDate(completionDate) {}
+    m_completionDate(completionDate) {
+}
 
 /*
 Function: JobCard (parameterized constructor with ID)
@@ -351,79 +354,41 @@ void JobCard::setCompletionDate(const util::Timestamp& completionDate)
 
 /*
 Function: serialize
-Description: Serializes the job card into a CSV-formatted string.
+Description: Serializes the JobCard object into a SerializedJobCard record.
 Parameters:
     - None
 Returns:
-    - std::string: Serialized job card record
+    - SerializedJobCard: Serialized representation of the job card
 */
-std::string JobCard::serialize() const
+SerializedJobCard JobCard::serialize() const
 {
-    std::ostringstream serializedJobCard;
-    serializedJobCard << m_id << ','
-        << m_bookingId << ','
-        << m_serviceId << ','
-        << m_technicianId << ','
-        << m_assignedDate.toString() << ','
-        << util::getServiceJobStatusString(m_status) << ','
-        << m_completionDate.toString();
-    return serializedJobCard.str();
+    SerializedJobCard serialized = {};
+    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    strcpy_s(serialized.bookingId, sizeof(serialized.bookingId), m_bookingId.c_str());
+    strcpy_s(serialized.serviceId, sizeof(serialized.serviceId), m_serviceId.c_str());
+    strcpy_s(serialized.technicianId, sizeof(serialized.technicianId), m_technicianId.c_str());
+    serialized.assignedDate = m_assignedDate;
+    serialized.status = m_status;
+    serialized.completionDate = m_completionDate;
+    return serialized;
 }
 
 /*
 Function: deserialize
-Description: Deserializes a CSV-formatted string into a JobCard object.
+Description: Deserializes a SerializedJobCard record into a JobCard object.
 Parameters:
-    - record: const std::string&, serialized job card record
+    - serializedJobCard: const SerializedJobCard&, serialized job card record
 Returns:
     - JobCard*: Pointer to the deserialized JobCard object
-Throws:
-    - std::runtime_error if timestamp parsing fails
 */
-JobCard* JobCard::deserialize(const std::string& record)
+JobCard* JobCard::deserialize(const SerializedJobCard& serializedJobCard)
 {
-    std::string id, bookingId, serviceId, technicianId;
-    std::string assignedDateString, statusString, completionDateString;
-    std::istringstream serializedJobCard(record);
-    getline(serializedJobCard, id, ',');
-    getline(serializedJobCard, bookingId, ',');
-    getline(serializedJobCard, serviceId, ',');
-    getline(serializedJobCard, technicianId, ',');
-    getline(serializedJobCard, assignedDateString, ',');
-    getline(serializedJobCard, statusString, ',');
-    getline(serializedJobCard, completionDateString, ',');
-    util::Timestamp assignedDate;
-    util::Timestamp completionDate;
-    try
-    {
-        assignedDate = util::Timestamp::fromString(assignedDateString);
-        completionDate = util::Timestamp::fromString(completionDateString);
-    }
-    catch (...)
-    {
-        throw std::runtime_error("Invalid timestamp");
-    }
-    util::ServiceJobStatus status = util::getServiceJobStatus(statusString);
     return Factory::getObject<JobCard>(
-        id,
-        bookingId,
-        serviceId,
-        technicianId,
-        assignedDate,
-        status,
-        completionDate
-    );
-}
-
-/*
-Function: getHeaders
-Description: Retrieves the CSV headers for job card serialization.
-Parameters:
-    - None
-Returns:
-    - std::string: Header string ("ID,BookingID,ServiceID,TechnicianID,AssignedDate,Status,CompletionDate")
-*/
-std::string JobCard::getHeaders()
-{
-    return "ID,BookingID,ServiceID,TechnicianID,AssignedDate,Status,CompletionDate";
+        serializedJobCard.id,
+        serializedJobCard.bookingId,
+        serializedJobCard.serviceId,
+        serializedJobCard.technicianId,
+        serializedJobCard.assignedDate,
+        serializedJobCard.status,
+        serializedJobCard.completionDate);
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/JobCard.h

@@ -15,6 +15,7 @@ Date:19-May-2026
 class ServiceBooking;
 class Service;
 class User;
+struct SerializedJobCard;
 
 class JobCard
 {
@@ -34,11 +35,11 @@ public:
     JobCard();
     JobCard(const std::string& bookingId,
         ServiceBooking* booking,
-        Service* service, 
-        const std::string& serviceId, 
-        const std::string& technicianId, 
-        User* technician, 
-        const util::Timestamp& assignedDate, 
+        Service* service,
+        const std::string& serviceId,
+        const std::string& technicianId,
+        User* technician,
+        const util::Timestamp& assignedDate,
         util::ServiceJobStatus status,
         const util::Timestamp& completionDate
     );
@@ -70,7 +71,6 @@ public:
     void setAssignedDate(const util::Timestamp& assignedDate);
     void setStatus(util::ServiceJobStatus status);
     void setCompletionDate(const util::Timestamp& completionDate);
-    std::string serialize() const;
-    static JobCard* deserialize(const std::string&);
-    static std::string getHeaders();
+    SerializedJobCard serialize() const;
+    static JobCard* deserialize(const SerializedJobCard&);
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Service.cpp

@@ -8,6 +8,7 @@ Date: 19-May-2026
 */
 
 #include <sstream>
+#include "SerializedRecords.h"
 #include "Service.h"
 #include "InventoryItem.h"
 #include "StringHelper.h"
@@ -27,7 +28,8 @@ Returns:
 Service::Service()
     : m_id("SRV" + std::to_string(++m_uid)),
     m_status(util::State::ACTIVE),
-    m_laborCost(0.0) {}
+    m_laborCost(0.0) {
+}
 
 /*
 Function: Service
@@ -44,7 +46,7 @@ Service::Service(const std::string& name, const util::Map<std::string, Inventory
     m_name(name),
     m_requiredInventoryItems(requiredInventoryItems),
     m_status(util::State::ACTIVE),
-    m_laborCost(laborCost) 
+    m_laborCost(laborCost)
 {
     int numberOfInventoryItems = m_requiredInventoryItems.getSize();
     auto inventoryItemPointers = m_requiredInventoryItems.getValues();
@@ -266,72 +268,38 @@ static util::Vector<std::string> getInventoryItemIDsAsVector(const std::string&
 
 /*
 Function: serialize
-Description: Serializes the service into a CSV-formatted string.
+Description: Serializes the Service object into a SerializedService record.
 Parameters:
     - None
 Returns:
-    - std::string: Serialized service record
+    - SerializedService: Serialized representation of the service
 */
-std::string Service::serialize() const
+SerializedService Service::serialize() const
 {
-    std::ostringstream serializedService;
-    serializedService << m_id << ','
-        << m_name << ','
-        << getInventoryItemIDsAsString(m_requiredInventoryItemIDs) << ','
-        << m_laborCost << ','
-        << util::getStateString(m_status);
-    return serializedService.str();
+    SerializedService serialized = {};
+    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    strcpy_s(serialized.name, sizeof(serialized.name), m_name.c_str());
+    strcpy_s(serialized.inventoryItemIDs, sizeof(serialized.inventoryItemIDs), getInventoryItemIDsAsString(m_requiredInventoryItemIDs).c_str());
+    serialized.laborCost = m_laborCost;
+    serialized.status = m_status;
+    return serialized;
 }
 
 /*
 Function: deserialize
-Description: Deserializes a CSV-formatted string into a Service object.
+Description: Deserializes a SerializedService record into a Service object.
 Parameters:
-    - record: const std::string&, serialized service record
+    - serializedService: const SerializedService&, serialized service record
 Returns:
     - Service*: Pointer to the deserialized Service object
-Throws:
-    - std::runtime_error if labor cost parsing fails
 */
-Service* Service::deserialize(const std::string& record)
+Service* Service::deserialize(const SerializedService& serializedService)
 {
-    std::string id, name;
-    std::string inventoryItemIDsString, laborCostString, statusString;
-    double laborCost;
-    std::istringstream serializedService(record);
-    getline(serializedService, id, ',');
-    getline(serializedService, name, ',');
-    getline(serializedService, inventoryItemIDsString, ',');
-    getline(serializedService, laborCostString, ',');
-    getline(serializedService, statusString, ',');
-    util::Vector<std::string> inventoryItemIDs = getInventoryItemIDsAsVector(inventoryItemIDsString);
-    try
-    {
-        laborCost = std::stod(laborCostString);
-    }
-    catch (...)
-    {
-        throw std::runtime_error("Invalid labor cost");
-    }
-    util::State status = util::getState(statusString);
+    util::Vector<std::string> inventoryItemIDs = getInventoryItemIDsAsVector(serializedService.inventoryItemIDs);
     return Factory::getObject<Service>(
-        id,
-        name,
+        serializedService.id,
+        serializedService.name,
         inventoryItemIDs,
-        laborCost,
-        status
-    );
-}
-
-/*
-Function: getHeaders
-Description: Retrieves the CSV headers for service serialization.
-Parameters:
-    - None
-Returns:
-    - std::string: Header string ("ID,Name,InventoryIDs,LaborCost,Status")
-*/
-std::string Service::getHeaders()
-{
-    return "ID,Name,InventoryIDs,LaborCost,Status";
+        serializedService.laborCost,
+        serializedService.status);
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Service.h

@@ -6,7 +6,6 @@ Author: Trenser
 Date: 19-May-2026
 */
 
-
 #pragma once
 #include <string>
 #include "Map.h"
@@ -14,6 +13,7 @@ Date: 19-May-2026
 #include "Enums.h"
 
 class InventoryItem;
+struct SerializedService;
 
 class Service
 {
@@ -40,7 +40,6 @@ public:
     void setRequiredInventoryItems(const util::Map<std::string, InventoryItem*>& requiredInventoryItems);
     void setLaborCost(double laborCost);
     void setState(util::State status);
-    std::string serialize() const;
-    static Service* deserialize(const std::string&);
-    static std::string getHeaders();
+    SerializedService serialize() const;
+    static Service* deserialize(const SerializedService&);
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ServiceBooking.cpp

@@ -6,8 +6,10 @@ Description: Implementation file containing the method definitions of the
 Author: Trenser
 Date:19-May-2026
 */
+
 #include <stdexcept>
 #include <sstream>
+#include "SerializedRecords.h"
 #include "ServiceBooking.h"
 #include "Service.h"
 #include "Enums.h"
@@ -28,7 +30,8 @@ ServiceBooking::ServiceBooking()
     m_customer(nullptr),
     m_assignedTechnician(nullptr),
     m_status(util::ServiceJobStatus::PENDING),
-    m_discountPercentage(0.0) {}
+    m_discountPercentage(0.0) {
+}
 
 /*
 Function: ServiceBooking
@@ -437,84 +440,46 @@ static util::Vector<std::string> getServiceIDsAsVector(const std::string& servic
 
 /*
 Function: serialize
-Description: Serializes the service booking into a CSV-formatted string.
+Description: Serializes the ServiceBooking object into a SerializedServiceBooking record.
 Parameters:
     - None
 Returns:
-    - std::string: Serialized booking record
+    - SerializedServiceBooking: Serialized representation of the service booking
 */
-std::string ServiceBooking::serialize() const
+SerializedServiceBooking ServiceBooking::serialize() const
 {
-    std::ostringstream serializedBooking;
-    serializedBooking << m_id << ','
-        << util::getServiceJobStatusString(m_status) << ','
-        << getServiceIDsAsString(m_serviceIDs) << ','
-        << m_customerId << ','
-        << m_vehicleNumber << ','
-        << m_vehicleBrand << ','
-        << m_vehicleModel << ','
-        << m_assignedTechnicianId << ','
-        << m_discountPercentage << ',';
-    return serializedBooking.str();
+    SerializedServiceBooking serialized = {};
+    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    strcpy_s(serialized.serviceIDs, sizeof(serialized.serviceIDs), getServiceIDsAsString(m_serviceIDs).c_str());
+    strcpy_s(serialized.customerId, sizeof(serialized.customerId), m_customerId.c_str());
+    strcpy_s(serialized.vehicleNumber, sizeof(serialized.vehicleNumber), m_vehicleNumber.c_str());
+    strcpy_s(serialized.vehicleBrand, sizeof(serialized.vehicleBrand), m_vehicleBrand.c_str());
+    strcpy_s(serialized.vehicleModel, sizeof(serialized.vehicleModel), m_vehicleModel.c_str());
+    strcpy_s(serialized.assignedTechnicianId, sizeof(serialized.assignedTechnicianId), m_assignedTechnicianId.c_str());
+    serialized.status = m_status;
+    serialized.discountPercentage = m_discountPercentage;
+    return serialized;
 }
 
 /*
 Function: deserialize
-Description: Deserializes a CSV-formatted string into a ServiceBooking object.
+Description: Deserializes a SerializedServiceBooking record into a ServiceBooking object.
 Parameters:
-    - record: const std::string&, serialized booking record
+    - serializedServiceBooking: const SerializedServiceBooking&, serialized service booking record
 Returns:
     - ServiceBooking*: Pointer to the deserialized ServiceBooking object
-Throws:
-    - std::runtime_error if discount percentage parsing fails
 */
-ServiceBooking* ServiceBooking::deserialize(const std::string& record)
+ServiceBooking* ServiceBooking::deserialize(const SerializedServiceBooking& serializedServiceBooking)
 {
-    std::string id, customerId, vehicleNumber, vehicleBrand, vehicleModel, assignedTechnicianId;
-    std::string serviceJobStatusString, serviceIDsString, discountPercentageString;
-    double discountPercentage;
-    std::istringstream serializedBooking(record);
-    getline(serializedBooking, id, ',');
-    getline(serializedBooking, serviceJobStatusString, ',');
-    getline(serializedBooking, serviceIDsString, ',');
-    getline(serializedBooking, customerId, ',');
-    getline(serializedBooking, vehicleNumber, ',');
-    getline(serializedBooking, vehicleBrand, ',');
-    getline(serializedBooking, vehicleModel, ',');
-    getline(serializedBooking, assignedTechnicianId, ',');
-    getline(serializedBooking, discountPercentageString, ',');
-    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serviceIDsString);
-    try
-    {
-        discountPercentage = std::stod(discountPercentageString);
-    }
-    catch (...)
-    {
-        throw std::runtime_error("Invalid discount percentage");
-    }
-    util::ServiceJobStatus status = util::getServiceJobStatus(serviceJobStatusString);
+    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serializedServiceBooking.serviceIDs);
     return Factory::getObject<ServiceBooking>(
-        id,
-        status,
+        serializedServiceBooking.id,
+        serializedServiceBooking.status,
         serviceIDs,
-        customerId,
-        vehicleNumber,
-        vehicleBrand,
-        vehicleModel,
-        assignedTechnicianId,
-        discountPercentage
-    );
-}
-
-/*
-Function: getHeaders
-Description: Retrieves the CSV headers for service booking serialization.
-Parameters:
-    - None
-Returns:
-    - std::string: Header string ("ID,Status,ServiceIDs,CustomerID,VehicleNumber,VehicleBrand,VehicleModel,AssignedTechnicianID,DiscountPercentage")
-*/
-std::string ServiceBooking::getHeaders()
-{
-    return "ID,Status,ServiceIDs,CustomerID,VehicleNumber,VehicleBrand,VehicleModel,AssignedTechnicianID,DiscountPercentage";
+        serializedServiceBooking.customerId,
+        serializedServiceBooking.vehicleNumber,
+        serializedServiceBooking.vehicleBrand,
+        serializedServiceBooking.vehicleModel,
+        serializedServiceBooking.assignedTechnicianId,
+        serializedServiceBooking.discountPercentage);
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ServiceBooking.h

@@ -6,6 +6,7 @@ Description: Header file declaring the ServiceBooking class, which represents
 Author: Trenser
 Date:19-May-2026
 */
+
 #pragma once
 #include <string>
 #include "Map.h"
@@ -14,6 +15,7 @@ Date:19-May-2026
 
 class Service;
 class User;
+struct SerializedServiceBooking;
 
 class ServiceBooking
 {
@@ -78,7 +80,6 @@ public:
     void setAssignedTechnicianId(const std::string& assignedTechnicianId);
     void setAssignedTechnician(User* assignedTechnician);
     void setDiscountPercentage(double discountPercentage);
-    std::string serialize() const;
-    static ServiceBooking* deserialize(const std::string&);
-    static std::string getHeaders();
+    SerializedServiceBooking serialize() const;
+    static ServiceBooking* deserialize(const SerializedServiceBooking&);
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/AuthenticationManagementService.cpp

@@ -10,6 +10,8 @@ Date:19-May-2026
 #include <stdexcept>
 #include "AuthenticationManagementService.h"
 #include "User.h"
+#include "Utility.h"
+#include "DataStoreLockGuard.h"
 
 User* AuthenticationManagementService::m_authenticatedUser = nullptr;
 
@@ -24,11 +26,12 @@ Return type: bool - true if login successful, false otherwise
 */
 bool AuthenticationManagementService::login(const std::string& username, const std::string& password)
 {
-	util::Map<std::string, User*> users = m_dataStore.getUsers();
-	int usersMapSize = users.getSize();
-	for (int index = 0; index < usersMapSize; index++)
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUserMap = m_dataStore.getUsers();
+	int trackedUserMapSize = trackedUserMap.getSize();
+	for (int index = 0; index < trackedUserMapSize; index++)
 	{
-		User* user = users.getValueAt(index);
+		User* user = trackedUserMap.getValueAt(index).data;
 		if (username == user->getUserName())
 		{
 			if (password == user->getPassword())
@@ -74,9 +77,18 @@ Return type: void
 */
 void AuthenticationManagementService::changePassword(const std::string& newPassword)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
 	if (m_authenticatedUser == nullptr)
 	{
 		throw std::runtime_error("There is no user currently logged in!");
 	}
+	int index = trackedUsersMap.find(m_authenticatedUser->getId());
+	if (index == -1)
+	{
+		throw std::runtime_error("User does not exist!\n");
+	}
 	m_authenticatedUser->setPassword(newPassword);
+	trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
+	m_dataStore.saveUsers();
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/InventoryManagementService.cpp

@@ -57,18 +57,19 @@ Returns:
 */
 void InventoryManagementService::sendLowStockAlerts()
 {
-	auto& inventoryItems = m_dataStore.getInventoryItems();
-	if (inventoryItems.isEmpty())
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedInventoryItemsMap = m_dataStore.getInventoryItems();
+	auto& trackedUserMap = m_dataStore.getUsers();
+	if (trackedInventoryItemsMap.isEmpty())
 	{
 		return;
 	}
-	int inventoryItemsSize = inventoryItems.getSize();
-	auto& usersMap = m_dataStore.getUsers();
-	int usersMapSize = usersMap.getSize();
+	int inventoryItemsSize = trackedInventoryItemsMap.getSize();
+	int usersMapSize = trackedUserMap.getSize();
 	util::Vector<User*> adminUsers;
 	for (int index = 0; index < usersMapSize; index++)
 	{
-		User* user = usersMap.getValueAt(index);
+		User* user = trackedUserMap.getValueAt(index).data;
 		if (user->getUserType() == util::UserType::ADMIN)
 		{
 			adminUsers.push_back(user);
@@ -81,7 +82,7 @@ void InventoryManagementService::sendLowStockAlerts()
 	}
 	for (int index = 0; index < inventoryItemsSize; index++)
 	{
-		InventoryItem* inventoryItem = inventoryItems.getValueAt(index);
+		InventoryItem* inventoryItem = trackedInventoryItemsMap.getValueAt(index).data;
 		if (inventoryItem && inventoryItem->getQuantity() < config::threshold::INVENTORY_LOW_STOCK_THRESHOLD)
 		{
 			sendLowStockAlertsToAdmins(*this, inventoryItem, adminUsers);
@@ -100,8 +101,11 @@ Return type: void
 */
 void InventoryManagementService::addInventoryItem(const std::string& partName, int quantity, double price)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
     InventoryItem* newItem = Factory::getObject<InventoryItem>(partName, quantity, price);
-    m_dataStore.getInventoryItems().insert(newItem->getId(), newItem);
+	trackedInventoryItemMap.insert(newItem->getId(), util::createNewRecord(newItem));
+	m_dataStore.saveInventoryItems();
 }
 
 /*
@@ -113,16 +117,22 @@ Return type: void
 */
 void InventoryManagementService::addInventoryItemStock(const std::string& selectedItemId, int quantity)
 {
-    int index = m_dataStore.getInventoryItems().find(selectedItemId);
-    if (index != -1)
-    {
-        InventoryItem* item = m_dataStore.getInventoryItems().getValueAt(index);
-        if (item != nullptr)
-        {
-            int totalQuantity = item->getQuantity() + quantity;
-            item->setQuantity(totalQuantity);
-        }
-    }
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
+	int index = trackedInventoryItemMap.find(selectedItemId);
+	if (index == -1)
+	{
+		throw std::runtime_error("Inventory update failed: Item ID '" + selectedItemId + "' not found.");
+	}
+	InventoryItem* item = trackedInventoryItemMap.getValueAt(index).data;
+	if (item == nullptr)
+	{
+		throw std::runtime_error("Inventory update failed. Item does not exist.\n");
+	}
+	int totalQuantity = item->getQuantity() + quantity;
+	item->setQuantity(totalQuantity);
+	trackedInventoryItemMap.getValueAt(index).state = RecordState::MODIFIED;
+	m_dataStore.saveInventoryItems();
 }
 
 /*
@@ -133,7 +143,10 @@ Return type: util::Map<std::string, InventoryItem*>
 */
 util::Map<std::string, InventoryItem*> InventoryManagementService::getInventoryItems()
 {
-	return m_dataStore.getInventoryItems();
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
+	auto inventoryMap = util::getObjects(trackedInventoryItemMap);
+	return inventoryMap;
 }
 
 /*
@@ -144,15 +157,21 @@ Return type: void
 */
 void InventoryManagementService::removeInventoryItem(const std::string& inventoryItemID)
 {
-    int index = m_dataStore.getInventoryItems().find(inventoryItemID);
-    if (index != -1)
-    {
-        InventoryItem* item = m_dataStore.getInventoryItems().getValueAt(index);
-        if (item != nullptr)
-        {
-            item->setState(util::State::INACTIVE);
-        }
-    }
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
+	int index = trackedInventoryItemMap.find(inventoryItemID);
+	if (index == -1)
+	{
+		throw std::runtime_error("Inventory removal failed: Item ID '" + inventoryItemID + "' not found.");
+	}
+	InventoryItem* item = trackedInventoryItemMap.getValueAt(index).data;
+	if (item == nullptr)
+	{
+		throw std::runtime_error("Inventory removal failed: Item ID does not exist.");
+	}
+	item->setState(util::State::INACTIVE);
+	trackedInventoryItemMap.getValueAt(index).state = RecordState::MODIFIED;
+	m_dataStore.saveInventoryItems();
 }
 
 /*
@@ -163,12 +182,19 @@ Return type: InventoryItem*
 */
 InventoryItem* InventoryManagementService::getInventoryItem(const std::string& inventoryItemID)
 {
-    int index = m_dataStore.getInventoryItems().find(inventoryItemID);
-    if (index != -1)
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
+    int index = trackedInventoryItemMap.find(inventoryItemID);
+    if (index == -1)
     {
-        return m_dataStore.getInventoryItems().getValueAt(index);
+		return nullptr;
     }
-    return nullptr;
+	InventoryItem* inventoryItem = trackedInventoryItemMap.getValueAt(index).data;
+	if (inventoryItem == nullptr)
+	{
+		throw std::runtime_error("Item ID does not exist.");
+	}
+	return inventoryItem;
 }
 
 /*

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/ServiceManagementService.cpp

@@ -24,6 +24,7 @@ Date:19-May-2026
 #include "Timestamp.h"
 #include "User.h"
 #include "UserManagementService.h"
+#include "DataStoreLockGuard.h"
 #include "Utility.h"
 #include "DataStoreLockGuard.h"
 
@@ -46,18 +47,19 @@ void ServiceManagementService::purchaseService(const util::Vector<std::string>&
 	{
 		throw std::runtime_error("No user is currently logged in!");
 	}
-	auto& servicesMap = m_dataStore.getServices();
-	auto& serviceBookingMap = m_dataStore.getServiceBookings();
+    DataStoreLockGuard lock(m_dataStore);
+	auto& trackedServicesMap = m_dataStore.getServices();
+	auto& trackedServiceBookingMap = m_dataStore.getServiceBookings();
 	util::Map<std::string, Service*> selectedServices;
 	int selectedServicesCount = serviceIDs.getSize();
 	for (int index = 0; index < selectedServicesCount; index++)
 	{
-		int serviceIndex = servicesMap.find(serviceIDs[index]);
+		int serviceIndex = trackedServicesMap.find(serviceIDs[index]);
 		if (serviceIndex == -1)
 		{
 			throw std::runtime_error("Service not found!");
 		}
-		Service* service = servicesMap.getValueAt(serviceIndex);
+		Service* service = trackedServicesMap.getValueAt(serviceIndex).data;
 		selectedServices[service->getId()] = service;
 	}
 	ServiceBooking* serviceBooking = Factory::getObject<ServiceBooking>(util::ServiceJobStatus::PENDING, selectedServices, authenticatedUser->getId(), authenticatedUser, vehicleNumber, vehicleBrand, vehicleModel, 0);
@@ -65,7 +67,7 @@ void ServiceManagementService::purchaseService(const util::Vector<std::string>&
 	{
 		throw std::runtime_error("Failed to create service booking");
 	}
-	serviceBookingMap[serviceBooking->getId()] = serviceBooking;
+	trackedServiceBookingMap[serviceBooking->getId()] =  util::createNewRecord(serviceBooking);
     std::string title = "Service Booking succeeded";
     std::string message = "Your service booking has been successfully placed with ID " + serviceBooking->getId();
     sendNotification(authenticatedUser, title, message);
@@ -90,21 +92,22 @@ void ServiceManagementService::purchaseComboPackage(const std::string& comboPack
 	{
 		throw std::runtime_error("No user is currently logged in!");
 	}
-	auto& comboPackagesMap = m_dataStore.getComboPackages();
-	auto& serviceBookingMap = m_dataStore.getServiceBookings();
-	int comboPackageIndex = comboPackagesMap.find(comboPackageID);
+    DataStoreLockGuard lock(m_dataStore);
+	auto& trackedComboPackagesMap = m_dataStore.getComboPackages();
+	auto& trackedServiceBookingMap = m_dataStore.getServiceBookings();
+	int comboPackageIndex = trackedComboPackagesMap.find(comboPackageID);
 	if (comboPackageIndex == -1)
 	{
 		throw std::runtime_error("Combo Package not found!");
 	}
-	const ComboPackage* comboPackage = comboPackagesMap[comboPackageID];
+	const ComboPackage* comboPackage = trackedComboPackagesMap[comboPackageID].data;
 	util::Map<std::string, Service*> selectedServices = comboPackage->getServices();
 	ServiceBooking* serviceBooking = Factory::getObject<ServiceBooking>(util::ServiceJobStatus::PENDING, selectedServices, authenticatedUser->getId(), authenticatedUser, vehicleNumber, vehicleBrand, vehicleModel, comboPackage->getDiscountPercentage());
 	if (serviceBooking == nullptr)
 	{
 		throw std::runtime_error("Failed to create combo package service booking");
 	}
-	serviceBookingMap[serviceBooking->getId()] = serviceBooking;
+	trackedServiceBookingMap[serviceBooking->getId()] = util::createNewRecord(serviceBooking);
     std::string title = "Combo Package Service Booking succeeded";
     std::string message = "Your service booking for the combo package has been successfully placed with ID " + serviceBooking->getId();
     sendNotification(authenticatedUser, title, message);
@@ -205,7 +208,7 @@ Description: Restores inventory quantities for all required items in the service
 Parameter: ServiceBooking* booking - Pointer to the booking whose inventory items need to be restored
 Return type: void
 */
-static void restoreInventory(ServiceBooking* booking)
+static void restoreInventory(ServiceBooking* booking, util::Map<std::string, TrackedRecord<InventoryItem>>& trackedInventoryItems)
 {
     const int INCREMENT_VALUE = 1;
     if (!booking) 
@@ -224,9 +227,17 @@ static void restoreInventory(ServiceBooking* booking)
         for (int InventoryIterator = 0; InventoryIterator < items.getSize(); ++InventoryIterator)
         {
             InventoryItem* item = items.getValueAt(InventoryIterator);
+            const std::string& currentItemId = item->getId();
+            int itemIndex = trackedInventoryItems.find(currentItemId);
+            if (itemIndex == -1)
+            {
+                continue;
+            }
+            auto& currentTrackedInventoryItem = trackedInventoryItems.getValueAt(itemIndex);
             if (item)
             {
                 item->setQuantity(item->getQuantity() + INCREMENT_VALUE);
+                currentTrackedInventoryItem.state = RecordState::MODIFIED;
             }
         }
     }
@@ -244,23 +255,28 @@ Parameters:
     util::UserType userType - Type of user initiating cancellation (CUSTOMER or TECHNICIAN)
 Return type: void
 */
-static void processBookingCancellation(ServiceBooking* booking,
-    util::Map<std::string, JobCard*>& jobs,
+static void processBookingCancellation(TrackedRecord<ServiceBooking>& trackedBooking,
+    util::Map<std::string, TrackedRecord<JobCard>>& jobs,
     ServiceManagementService& currentService,
-    util::UserType userType)
+    util::UserType userType,
+    util::Map<std::string, TrackedRecord<InventoryItem>>& trackedInventoryItems)
 {
+    ServiceBooking* booking = trackedBooking.data;
     if (!booking)
     {
         return;
     }
+    const std::string& bookingId = booking->getId();
     for (int jobIterator = 0; jobIterator < jobs.getSize(); ++jobIterator)
     {
-        JobCard* jobCard = jobs.getValueAt(jobIterator);
+        auto& trackedJobCard = jobs.getValueAt(jobIterator);
+        JobCard* jobCard = trackedJobCard.data;
         if (!jobCard || jobCard->getBookingId() != booking->getId() || jobCard->getStatus() == util::ServiceJobStatus::CANCELLED)
         {
             continue;
         }
         jobCard->setStatus(util::ServiceJobStatus::CANCELLED);
+        trackedJobCard.state = RecordState::MODIFIED;
         if (userType == util::UserType::CUSTOMER)
         {
             if (User* technician = booking->getAssignedTechnician())
@@ -293,7 +309,8 @@ static void processBookingCancellation(ServiceBooking* booking,
     }
     booking->setAssignedTechnician(nullptr);
     booking->setAssignedTechnicianId("");
-    restoreInventory(booking);
+    trackedBooking.state = RecordState::MODIFIED;
+    restoreInventory(booking, trackedInventoryItems);
 }
 
 /*
@@ -306,22 +323,25 @@ Return type: void
 */
 void ServiceManagementService::cancelCustomerServiceBookings(const std::string& customerID)
 {
-    auto& users = m_dataStore.getUsers();
-    int userIndex = users.find(customerID);
+    DataStoreLockGuard lock(m_dataStore);
+    auto& trackedUsers = m_dataStore.getUsers();
+    int userIndex = trackedUsers.find(customerID);
     if (userIndex == -1)
     {
         throw std::runtime_error("User not found: " + customerID);
     }
-    User* customer = users.getValueAt(userIndex);
+    User* customer = trackedUsers.getValueAt(userIndex).data;
     if (!customer)
     {
         throw std::runtime_error("User not found: " + customerID);
     }
-    auto& bookings = m_dataStore.getServiceBookings();
-    auto& jobs = m_dataStore.getJobCards();
-    for (int iteratorOne = 0; iteratorOne < bookings.getSize(); iteratorOne++)
+    auto& trackedBookings = m_dataStore.getServiceBookings();
+    auto& trackedJobs = m_dataStore.getJobCards();
+    auto& trackedInventoryItems = m_dataStore.getInventoryItems();
+    for (int iteratorOne = 0; iteratorOne < trackedBookings.getSize(); iteratorOne++)
     {
-        ServiceBooking* booking = bookings.getValueAt(iteratorOne);
+        auto& trackedBooking = trackedBookings.getValueAt(iteratorOne);
+        ServiceBooking* booking = trackedBooking.data;
         if (!booking)
         {
             continue;
@@ -336,8 +356,12 @@ void ServiceManagementService::cancelCustomerServiceBookings(const std::string&
         {
             continue;
         }
-        processBookingCancellation(booking, jobs, *this, util::UserType::CUSTOMER);
+        processBookingCancellation(trackedBooking, trackedJobs, *this, util::UserType::CUSTOMER, trackedInventoryItems);
     }
+    m_dataStore.saveUsers();
+    m_dataStore.saveServiceBookings();
+    m_dataStore.saveJobCards();
+    m_dataStore.saveInventoryItems();
 }
 
 /*
@@ -349,22 +373,25 @@ Return type: void
 */
 void ServiceManagementService::cancelTechnicianJobs(const std::string& technicianID)
 {
-    auto& users = m_dataStore.getUsers();
-    int userIndex = users.find(technicianID);
+    DataStoreLockGuard lock(m_dataStore);
+    auto& trackedUsers = m_dataStore.getUsers();
+    int userIndex = trackedUsers.find(technicianID);
     if (userIndex == -1)
     {
         throw std::runtime_error("User not found: " + technicianID);
     }
-    User* technician = users.getValueAt(userIndex);
+    User* technician = trackedUsers.getValueAt(userIndex).data;
     if (!technician)
     {
         throw std::runtime_error("User not found: " + technicianID);
     }
-    auto& bookings = m_dataStore.getServiceBookings();
-    auto& jobs = m_dataStore.getJobCards();
-    for (int iteratorOne = 0; iteratorOne < bookings.getSize(); iteratorOne++)
+    auto& trackedBookings = m_dataStore.getServiceBookings();
+    auto& trackedJobs = m_dataStore.getJobCards();
+    auto& trackedInventoryItems = m_dataStore.getInventoryItems();
+    for (int iteratorOne = 0; iteratorOne < trackedBookings.getSize(); iteratorOne++)
     {
-        ServiceBooking* booking = bookings.getValueAt(iteratorOne);
+        auto& trackedBooking = trackedBookings.getValueAt(iteratorOne);
+        ServiceBooking* booking = trackedBooking.data;
         if (!booking)
         {
             continue;
@@ -385,8 +412,12 @@ void ServiceManagementService::cancelTechnicianJobs(const std::string& technicia
         {
             continue;
         }
-        processBookingCancellation(booking, jobs, *this, util::UserType::TECHNICIAN);
+        processBookingCancellation(trackedBooking, trackedJobs, *this, util::UserType::TECHNICIAN, trackedInventoryItems);
     }
+    m_dataStore.saveUsers();
+    m_dataStore.saveInventoryItems();
+    m_dataStore.saveServiceBookings();
+    m_dataStore.saveJobCards();
 }
 
 /*
@@ -400,6 +431,7 @@ Return type: void
 */
 void ServiceManagementService::createComboPackage(const std::string& packageName, const util::Vector<std::string>& serviceIDsInNewCombo, double discountPercentage)
 {
+    DataStoreLockGuard lock(m_dataStore);
     if (packageName.empty())
     {
         throw std::invalid_argument("The Combo Package Name cannot be empty.\n");
@@ -412,19 +444,19 @@ void ServiceManagementService::createComboPackage(const std::string& packageName
     {
         throw std::invalid_argument("Discount percentage must be between 0 and 100.");
     }
-    auto& servicesMap = m_dataStore.getServices();
+    auto& trackedServicesMap = m_dataStore.getServices();
     for (int index = 0; index < serviceIDsInNewCombo.getSize(); index++)
     {
-        const std::string serviceid = serviceIDsInNewCombo[index];
-        if (servicesMap.find(serviceid) == -1)
+        const std::string& serviceid = serviceIDsInNewCombo[index];
+        if (trackedServicesMap.find(serviceid) == -1)
         {
             throw std::runtime_error("Service ID not found: " + serviceid);
         }
     }
-    auto& comboPackageMap = m_dataStore.getComboPackages();
-    for (int iterator = 0; iterator < comboPackageMap.getSize(); iterator++)
+    auto& trackedComboPackageMap = m_dataStore.getComboPackages();
+    for (int iterator = 0; iterator < trackedComboPackageMap.getSize(); iterator++)
     {
-        ComboPackage* existingCombos = comboPackageMap.getValueAt(iterator);
+        ComboPackage* existingCombos = trackedComboPackageMap.getValueAt(iterator).data;
         const util::Map<std::string, Service*>& servicesInsideExistingCombos = existingCombos->getServices();
         if (servicesInsideExistingCombos.getSize() == serviceIDsInNewCombo.getSize())
         {
@@ -448,15 +480,16 @@ void ServiceManagementService::createComboPackage(const std::string& packageName
     for (int iteratorOne = 0; iteratorOne < serviceIDsInNewCombo.getSize(); iteratorOne++)
     {
         const std::string& serviceId = serviceIDsInNewCombo[iteratorOne];
-        int serviceIndex = servicesMap.find(serviceId);
+        int serviceIndex = trackedServicesMap.find(serviceId);
         if (serviceIndex == -1)
         {
             throw std::runtime_error("Service ID not found: " + serviceId);
         }
-        selectedServices.insert(serviceId, servicesMap.getValueAt(serviceIndex));
+        selectedServices.insert(serviceId, trackedServicesMap.getValueAt(serviceIndex).data);
     }
     ComboPackage* newComboPackage = Factory::getObject<ComboPackage>(packageName, discountPercentage, selectedServices);
-    comboPackageMap.insert(newComboPackage->getId(), newComboPackage);
+    trackedComboPackageMap.insert(newComboPackage->getId(), util::createNewRecord(newComboPackage));
+    m_dataStore.saveComboPackages();
 }
 
 /*
@@ -467,7 +500,10 @@ Return type: util::Map<std::string, ComboPackage*>
 */
 util::Map<std::string, ComboPackage*> ServiceManagementService::getComboPackages()
 {
-    return m_dataStore.getComboPackages();
+    DataStoreLockGuard lock(m_dataStore);
+    util::Map<std::string, ComboPackage*> comboPackages;
+    comboPackages = util::getObjects(m_dataStore.getComboPackages());
+    return comboPackages;
 }
 
 /*
@@ -478,14 +514,17 @@ Return type: void
 */
 void ServiceManagementService::removeComboPackage(const std::string& comboPackageID)
 {
+    DataStoreLockGuard lock(m_dataStore);
     bool removed = false;
-    util::Map<std::string, ComboPackage*>& currentComboPackages = m_dataStore.getComboPackages();
-    for (int iterator = 0; iterator < currentComboPackages.getSize(); iterator++)
+    auto& trackedComboPackages = m_dataStore.getComboPackages();
+    for (int iterator = 0; iterator < trackedComboPackages.getSize(); iterator++)
     {
-        ComboPackage* currentComboPackage = currentComboPackages.getValueAt(iterator);
+        auto& comboPackage = trackedComboPackages.getValueAt(iterator);
+        ComboPackage* currentComboPackage = comboPackage.data;
         if (currentComboPackage && currentComboPackage->getId() == comboPackageID)
         {
             currentComboPackage->setState(util::State::INACTIVE);
+            comboPackage.state = RecordState::MODIFIED;
             removed = true;
             break;
         }
@@ -494,6 +533,7 @@ void ServiceManagementService::removeComboPackage(const std::string& comboPackag
     {
         throw std::runtime_error("Combo package with ID '" + comboPackageID + "' not found.");
     }
+    m_dataStore.saveComboPackages();
 }
 
 /*
@@ -506,7 +546,10 @@ Returns:
 */
 util::Map<std::string, ServiceBooking*> ServiceManagementService::getServiceBookings()
 {
-	return m_dataStore.getServiceBookings();
+    DataStoreLockGuard lock(m_dataStore);
+    util::Map<std::string, ServiceBooking*> serviceBookings;
+    serviceBookings = util::getObjects(m_dataStore.getServiceBookings());
+    return serviceBookings;
 }
 
 /*
@@ -545,9 +588,10 @@ Throws:
 */
 void ServiceManagementService::createJobCard(const std::string& bookingID, const std::string& technicianID, const std::string& serviceID)
 {
+    DataStoreLockGuard lock(m_dataStore);
 	UserManagementService m_userManagementService;
 	ServiceBooking* currentBooking = getServiceBooking(bookingID);
-	auto& currentJobCards = m_dataStore.getJobCards();
+	auto& currentTrackedJobCards = m_dataStore.getJobCards();
 	if (currentBooking == nullptr)
 	{
 		throw std::runtime_error("Service Booking not available");
@@ -593,7 +637,7 @@ void ServiceManagementService::createJobCard(const std::string& bookingID, const
 	JobCard* jobCard = Factory::getObject<JobCard>(bookingID, currentBooking, currentService, serviceID, technicianID, selectedTechnician, util::Timestamp(), util::ServiceJobStatus::STARTED, util::Timestamp());
 	if (jobCard)
 	{
-		currentJobCards.insert(jobCard->getId(), jobCard);
+		currentTrackedJobCards.insert(jobCard->getId(), util::createNewRecord(jobCard));
 		sendNotification(selectedTechnician, title, message);
 	}
 	else
@@ -603,6 +647,7 @@ void ServiceManagementService::createJobCard(const std::string& bookingID, const
     title = "Technician assigned";
     message = "A technician has been assigned to your Service Booking with ID " + bookingID;
     sendNotification(currentBooking->getCustomer(), title, message);
+    m_dataStore.saveJobCards();
 }
 
 /*
@@ -620,15 +665,17 @@ Throws:
 */
 void ServiceManagementService::createService(const std::string& name, const util::Vector<std::string>& inventoryItemIDs, double laborCost)
 {
+    DataStoreLockGuard lock(m_dataStore);
 	util::Map<std::string, InventoryItem*> currentServiceInventoryItems;
-	auto inventoryItems = m_dataStore.getInventoryItems();
+	auto& trackedInventoryItems = m_dataStore.getInventoryItems();
+    auto& currentServices = m_dataStore.getServices();
 	for (int iteratorOne =0; iteratorOne < inventoryItemIDs.getSize(); iteratorOne++)
 	{
 		std::string currentItemID = inventoryItemIDs[iteratorOne];
 		bool itemFound = false;
-		for (int iteratorTwo = 0; iteratorTwo < inventoryItems.getSize(); iteratorTwo++)
+		for (int iteratorTwo = 0; iteratorTwo < trackedInventoryItems.getSize(); iteratorTwo++)
 		{
-			InventoryItem* currentInventoryItem = inventoryItems.getValueAt(iteratorTwo);
+			InventoryItem* currentInventoryItem = trackedInventoryItems.getValueAt(iteratorTwo).data;
 			if (currentInventoryItem && currentInventoryItem->getId() == currentItemID)
 			{
 				itemFound = true;
@@ -646,12 +693,12 @@ void ServiceManagementService::createService(const std::string& name, const util
 	{
 		throw std::runtime_error("Unable to create new service.");
 	}
-	util::Map<std::string, Service*>& currentServices = m_dataStore.getServices();
 	if (currentServices.find(newService->getId()) != -1)
 	{
 		throw std::runtime_error("Service with this ID Already exists.");
 	}
-	currentServices.insert(newService->getId(), newService);
+	currentServices.insert(newService->getId(), util::createNewRecord(newService));
+    m_dataStore.saveServices();
 }
 
 /*
@@ -664,7 +711,10 @@ Returns:
 */
 util::Map<std::string, Service*> ServiceManagementService::getServices()
 {
-	return m_dataStore.getServices();
+    DataStoreLockGuard lock(m_dataStore);
+    util::Map<std::string, Service*> services;
+    services = util::getObjects(m_dataStore.getServices());
+    return services;
 }
 
 /*
@@ -679,14 +729,19 @@ Throws:
 */
 void ServiceManagementService::removeService(const std::string& serviceID)
 {
-	util::Map<std::string, Service*>& currentServices = m_dataStore.getServices();
-    util::Map<std::string, ComboPackage*>& currentComboPackages =  m_dataStore.getComboPackages();
-	if (currentServices.find(serviceID) != -1)
+    DataStoreLockGuard lock(m_dataStore);
+	auto& currentTrackedServices = m_dataStore.getServices();
+    auto& currentTrackedComboPackages =  m_dataStore.getComboPackages();
+	if (currentTrackedServices.find(serviceID) != -1)
 	{
-		currentServices.getValueAt(currentServices.find(serviceID))->setState(util::State::INACTIVE);
-        for (int iterator = 0; iterator < currentComboPackages.getSize(); iterator++)
+        int serviceIndex, comboPackageIndex;
+        serviceIndex = currentTrackedServices.find(serviceID);
+		currentTrackedServices.getValueAt(serviceIndex).data->setState(util::State::INACTIVE);
+        currentTrackedServices.getValueAt(serviceIndex).state = RecordState::MODIFIED;
+        for (int iterator = 0; iterator < currentTrackedComboPackages.getSize(); iterator++)
         {
-            ComboPackage* currentComboPackage = currentComboPackages.getValueAt(iterator);
+            comboPackageIndex = iterator;
+            ComboPackage* currentComboPackage = currentTrackedComboPackages.getValueAt(iterator).data;
             if (currentComboPackage && currentComboPackage->getState() == util::State::ACTIVE)
             {
                 util::Map<std::string, Service*> currentServices = currentComboPackage->getServices();
@@ -696,6 +751,7 @@ void ServiceManagementService::removeService(const std::string& serviceID)
                     if (currentService->getId() == serviceID)
                     {
                         currentComboPackage->setState(util::State::INACTIVE);
+                        currentTrackedComboPackages.getValueAt(comboPackageIndex).state = RecordState::MODIFIED;
                         break;
                     }
                 }
@@ -706,6 +762,8 @@ void ServiceManagementService::removeService(const std::string& serviceID)
 	{
 		throw std::runtime_error("Service not found.");
 	}
+    m_dataStore.saveServices();
+    m_dataStore.saveComboPackages();
 }
 
 /*
@@ -744,11 +802,12 @@ Returns:
 */
 util::Map<std::string, JobCard*> ServiceManagementService::getJobCards(const std::string& technicianID)
 {
-	util::Map<std::string, JobCard*> jobCards = m_dataStore.getJobCards();
+    DataStoreLockGuard lock(m_dataStore);
+	auto& trackedJobCards = m_dataStore.getJobCards();
 	util::Map<std::string, JobCard*> technicianJobCards;
-	for (int iterator = 0; iterator < jobCards.getSize(); iterator++)
+	for (int iterator = 0; iterator < trackedJobCards.getSize(); iterator++)
 	{
-		JobCard* currentJobCard = jobCards.getValueAt(iterator);
+		JobCard* currentJobCard = trackedJobCards.getValueAt(iterator).data;
 		if (currentJobCard->getTechnicianId() == technicianID)
 		{
 			technicianJobCards.insert(currentJobCard->getId(), currentJobCard);
@@ -797,6 +856,7 @@ Returns:
 */
 void ServiceManagementService::updateJobStatus(const std::string& jobID)
 {
+    DataStoreLockGuard lock(m_dataStore);
 	AuthenticationManagementService authenticationManagementService;
 	PaymentManagementService paymentManagementService;
 	bool jobStatusUpdated = false, serviceBookingCompleted;
@@ -811,8 +871,15 @@ void ServiceManagementService::updateJobStatus(const std::string& jobID)
 	{
 		throw std::runtime_error("No job cards assigned to the technician.");
 	}
+    auto& trackedJobCards = m_dataStore.getJobCards();
+    auto& trackedServiceBookings = m_dataStore.getServiceBookings();
 	if (currentAssignedJobs.find(jobID) != -1)
 	{
+        int jobIndex = trackedJobCards.find(jobID);
+        if (jobIndex == -1)
+        {
+            throw std::runtime_error("Unable to fetch current job.");
+        }
 		currentJob = currentAssignedJobs.getValueAt(currentAssignedJobs.find(jobID));
 		if (currentJob == nullptr)
 		{
@@ -821,16 +888,20 @@ void ServiceManagementService::updateJobStatus(const std::string& jobID)
 		if (currentJob->getStatus() == util::ServiceJobStatus::STARTED)
 		{
 			currentJob->setStatus(util::ServiceJobStatus::IN_PROGRESS);
+            trackedJobCards.getValueAt(jobIndex).state = RecordState::MODIFIED;
 			jobStatusUpdated = true;
 		}
         else if (currentJob->getStatus() == util::ServiceJobStatus::IN_PROGRESS)
         {
             currentJob->setStatus(util::ServiceJobStatus::COMPLETED);
+            trackedJobCards.getValueAt(jobIndex).state = RecordState::MODIFIED;
             jobStatusUpdated = true;
             serviceBookingCompleted = hasCompletedAllJobs(currentJob->getBookingId(), currentAssignedJobs);
             if (serviceBookingCompleted)
             {
+                const std::string& bookingId = currentJob->getBookingId();
                 currentJob->getBooking()->setStatus(util::ServiceJobStatus::COMPLETED);
+                trackedServiceBookings.getValueAt(trackedServiceBookings.find(bookingId)).state = RecordState::MODIFIED;
                 paymentManagementService.generateInvoice(currentJob->getBooking());
                 std::string title = "Service Booking completed. Invoice Generated.";
                 std::string message = "Services completed for the booking and invoice generated.";
@@ -846,4 +917,6 @@ void ServiceManagementService::updateJobStatus(const std::string& jobID)
 	{
 		throw std::runtime_error("Failed to update job status. Job may already be completed.");
 	}
+    m_dataStore.saveJobCards();
+    m_dataStore.saveServiceBookings();
 }