diff --git a/src/entity.cpp b/src/entity.cpp
index a04bb21..e493caf 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -4,12 +4,12 @@
 #include <iostream>
 
 namespace envlibcpp {
-    Entity::Entity(std::string entityName) {
-        id = rand() % 100 + 1;
+    Entity::Entity(int identifier, std::string entityName) {
+        id = identifier;
         name = entityName;
         environmentId = -1;
         gridId = -1;
-        locationId = -1;
+        locationId = "N/S";
     }
 
     int Entity::getId() {
@@ -28,7 +28,7 @@ namespace envlibcpp {
         return gridId;
     }
 
-    int Entity::getLocationId() {
+    std::string Entity::getLocationId() {
         return locationId;
     }
 
@@ -44,7 +44,11 @@ namespace envlibcpp {
         gridId = id;
     }
 
-    void Entity::setLocationId(int id) {
+    void Entity::setLocationId(std::string id) {
         locationId = id;
     }
+
+    void Entity::resetLocationId() {
+        setLocationId("N/S");
+    }
 }
\ No newline at end of file
diff --git a/src/environment.cpp b/src/environment.cpp
index 8d0656b..26dedd2 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -3,10 +3,14 @@
 #include <iostream>
 
 namespace envlibcpp {
-    Environment::Environment(std::string envName, int size) {
-        id = rand() % 100 + 1;
+    Environment::Environment(int identifier, std::string envName, int size) {
+        id = identifier;
         name = envName;
-        grid = Grid(size);
+        grid = new Grid(id, size);
+    }
+
+    Environment::~Environment() {
+        free(grid);
     }
 
     int Environment::getId() {
@@ -17,7 +21,7 @@ namespace envlibcpp {
         return name;
     }
 
-    Grid& Environment::getGrid() {
+    Grid* Environment::getGrid() {
         return grid;
     }
 
@@ -27,25 +31,25 @@ namespace envlibcpp {
 
     void Environment::addEntity(Entity& entity) {
         entity.setEnvironmentId(id);
-        grid.addEntity(entity);
+        grid->addEntity(entity);
     }
 
     void Environment::addEntityToLocation(Entity& entity, Location& location) {
         entity.setEnvironmentId(id);
-        grid.addEntityToLocation(entity, location);
+        grid->addEntityToLocation(entity, location);
     }
 
     void Environment::removeEntity(Entity& entity) {
         entity.setEnvironmentId(-1);
-        grid.removeEntity(entity);
+        grid->removeEntity(entity);
     }
 
     bool Environment::isEntityPresent(Entity& entity) {
-        return grid.isEntityPresent(entity);
+        return grid->isEntityPresent(entity);
     }
 
     int Environment::getNumEntities() {
-        return grid.getNumEntities();
+        return grid->getNumEntities();
     }
     
     void Environment::printInfo() {
@@ -53,8 +57,8 @@ namespace envlibcpp {
         std::cout << "Num entities: " << getNumEntities() << std::endl;
     }
 
-    envlibcpp::Entity& Environment::getFirstEntity() {
-        for (envlibcpp::Location& location : getGrid().getLocations()) {
+    Entity& Environment::getFirstEntity() {
+        for (Location& location : getGrid()->getLocations()) {
             if (location.getNumEntities() > 0) {
                 return location.getEntities()[0];
             }
@@ -62,9 +66,9 @@ namespace envlibcpp {
         throw new std::exception();
     }
 
-    envlibcpp::Entity& Environment::getEntity(int entityId) {
-        for (envlibcpp::Location& location : getGrid().getLocations()) {
-            for (envlibcpp::Entity& entity : location.getEntities()) {
+    Entity& Environment::getEntity(int entityId) {
+        for (Location& location : getGrid()->getLocations()) {
+            for (Entity& entity : location.getEntities()) {
                 if (entity.getId() == entityId) {
                     return entity;
                 }
diff --git a/src/grid.cpp b/src/grid.cpp
index 6d0692f..d86c171 100644
--- a/src/grid.cpp
+++ b/src/grid.cpp
@@ -3,12 +3,8 @@
 #include <iostream>
 
 namespace envlibcpp {
-    Grid::Grid() {
-        Grid(4);
-    }
-
-    Grid::Grid(int gridSize) {
-        id = rand() % 100 + 1;
+    Grid::Grid(int identifier, int gridSize) {
+        id = identifier;
         size = gridSize;
         generateLocations();
     }
@@ -84,7 +80,7 @@ namespace envlibcpp {
         for (Location& location : locations) {
             if (location.isEntityPresent(entity)) {
                 location.removeEntity(entity);
-                entity.setLocationId(-1);
+                entity.resetLocationId();
             }
         }
         entity.setGridId(-1);
@@ -99,7 +95,7 @@ namespace envlibcpp {
         return false;
     }
 
-    Location& Grid::getLocation(int locationId) {
+    Location& Grid::getLocation(std::string locationId) {
         for (Location& location : locations) {
             if (location.getId() == locationId) {
                 return location;
@@ -116,7 +112,8 @@ namespace envlibcpp {
     void Grid::generateLocations() {
         for (int y = 0; y < getSize(); y++) {
             for (int x = 0; x < getSize(); x++) {
-                Location location(x, y);
+                std::string identifier = "" + std::to_string(getId()) + "-" + std::to_string(x) + "-" + std::to_string(y);
+                Location location(identifier, x, y);
                 locations.push_back(location);
             }
         }
diff --git a/src/header/entity.h b/src/header/entity.h
index 9fcf280..b3c441e 100644
--- a/src/header/entity.h
+++ b/src/header/entity.h
@@ -9,23 +9,24 @@ namespace envlibcpp {
     // @since August 26th, 2022
     class Entity {
         public:
-            Entity(std::string entityName);
+            Entity(int id, std::string entityName);
             int getId();
             std::string getName();
             int getEnvironmentId();
             int getGridId();
-            int getLocationId();
+            std::string getLocationId();
             void setName(std::string newName);
             void setEnvironmentId(int id);
             void setGridId(int id);
-            void setLocationId(int id);
-            envlibcpp::Entity& getEntity(int entityId);
+            void setLocationId(std::string id);
+            void resetLocationId();
+            Entity& getEntity(int entityId);
         private:
             int id;
             std::string name;
             int environmentId;
             int gridId;
-            int locationId;
+            std::string locationId;
     };
 }
 
diff --git a/src/header/environment.h b/src/header/environment.h
index c9fcbb3..202e374 100644
--- a/src/header/environment.h
+++ b/src/header/environment.h
@@ -11,10 +11,11 @@ namespace envlibcpp {
     // @since August 26th, 2022
     class Environment {
         public:
-            Environment(std::string envName, int size);
+            Environment(int id, std::string envName, int size);
+            ~Environment();
             int getId();
             std::string getName();
-            Grid& getGrid();
+            Grid* getGrid();
             void setName(std::string newName);
             void addEntity(Entity& entity);
             void addEntityToLocation(Entity& entity, Location& location);
@@ -22,12 +23,12 @@ namespace envlibcpp {
             bool isEntityPresent(Entity& entity);
             int getNumEntities();
             void printInfo();
-            envlibcpp::Entity& getFirstEntity();
-            envlibcpp::Entity& getEntity(int entityId);
+            Entity& getFirstEntity();
+            Entity& getEntity(int entityId);
         private:
             int id;
             std::string name;
-            Grid grid;
+            Grid* grid;
     };
 }
 
diff --git a/src/header/grid.h b/src/header/grid.h
index 23e44fe..d74ad38 100644
--- a/src/header/grid.h
+++ b/src/header/grid.h
@@ -12,8 +12,8 @@ namespace envlibcpp {
     // @since August 26th, 2022
     class Grid {
         public:
-            Grid();
-            Grid(int gridSize);
+            Grid() = delete;
+            Grid(int id, int gridSize);
             int getId();
             std::vector<Location>& getLocations();
             Location& getFirstLocation();
@@ -28,7 +28,7 @@ namespace envlibcpp {
             void addEntityToLocation(Entity& entity, Location& location);
             void removeEntity(Entity& entity);
             bool isEntityPresent(Entity& entity);
-            Location& getLocation(int locationId);
+            Location& getLocation(std::string locationId);
             Location& getRandomLocation();
         private:
             int id;
diff --git a/src/header/location.h b/src/header/location.h
index 8080aa5..2607450 100644
--- a/src/header/location.h
+++ b/src/header/location.h
@@ -12,8 +12,8 @@ namespace envlibcpp {
     // @since August 26th, 2022
     class Location {
         public:
-            Location(int xpos, int ypos);
-            int getId();
+            Location(std::string id, int xpos, int ypos);
+            std::string getId();
             int getX();
             int getY();
             int getNumEntities();
@@ -22,7 +22,7 @@ namespace envlibcpp {
             bool isEntityPresent(Entity& entity);
             std::vector<Entity>& getEntities();
         private:
-            int id;
+            std::string id;
             int x;
             int y;
             std::vector<Entity> entities;
diff --git a/src/location.cpp b/src/location.cpp
index a38b65f..7d5ef53 100644
--- a/src/location.cpp
+++ b/src/location.cpp
@@ -3,13 +3,13 @@
 #include <iostream>
 
 namespace envlibcpp {
-    Location::Location(int xpos, int ypos) {
-        id = rand() % 100 + 1;
+    Location::Location(std::string identifier, int xpos, int ypos) {
+        id = identifier;
         x = xpos;
         y = ypos;
     }
 
-    int Location::getId() {
+    std::string Location::getId() {
         return id;
     }
 
@@ -41,7 +41,7 @@ namespace envlibcpp {
         if (index != -1) {
             entities.erase(entities.begin() + index);
         }
-        entity.setLocationId(-1);
+        entity.resetLocationId();
     }
     
     bool Location::isEntityPresent(Entity& entity) {
diff --git a/src/tests.cpp b/src/tests.cpp
index 5fdb41c..573c707 100644
--- a/src/tests.cpp
+++ b/src/tests.cpp
@@ -19,8 +19,8 @@ void testTemplate() {
 void testPlacingEntityInLocation() {
     std::cout << "---" << std::endl;
     std::cout << "Test 1 - Placing entity in location" << std::endl;
-    Entity entity("Daniel");
-    Location location(0, 0);
+    Entity entity(0, "Daniel");
+    Location location("my location id", 0, 0);
     location.addEntity(entity);
     assert(location.isEntityPresent(entity) == true);
     assert(entity.getLocationId() == location.getId());
@@ -30,12 +30,12 @@ void testPlacingEntityInLocation() {
 void testRemovingEntityFromLocation() {
     std::cout << "---" << std::endl;
     std::cout << "Test 2 - Removing entity from location" << std::endl;
-    Entity entity("Daniel");
-    Location location(0, 0);
+    Entity entity(0, "Daniel");
+    Location location("location-0-0", 0, 0);
     location.addEntity(entity);
     location.removeEntity(entity);
     assert(!location.isEntityPresent(entity));
-    assert(entity.getLocationId() == -1);
+    assert(entity.getLocationId() == "N/S");
     std::cout << "Success" << std::endl;
 }
 
@@ -43,8 +43,8 @@ void testGeneratingGrid() {
     std::cout << "---" << std::endl;
     std::cout << "Test 3 - Generating grid" << std::endl;
     int size = 4;
-    Environment environment("test environment", 4);
-    int numLocations = environment.getGrid().getLocations().size();
+    Environment environment(0, "test environment", 4);
+    int numLocations = environment.getGrid()->getLocations().size();
     int expectedNumLocations = size*size;
     assert(numLocations == expectedNumLocations);
     std::cout << "Success" << std::endl;
@@ -53,7 +53,7 @@ void testGeneratingGrid() {
 void testRetrievingLocation() {
     std::cout << "---" << std::endl;
     std::cout << "Test 4 - Retrieving location" << std::endl;
-    Grid grid(5);
+    Grid grid(0, 5);
     Location firstLocation = grid.getFirstLocation();
     assert(firstLocation.getX() == 0 && firstLocation.getY() == 0);
     std::cout << "Success" << std::endl;
@@ -62,9 +62,9 @@ void testRetrievingLocation() {
 void testRetrievingLocationAfterModification() {
     std::cout << "---" << std::endl;
     std::cout << "Test 5 - Retrieving location after modification" << std::endl;
-    Grid grid(5);
+    Grid grid(0, 5);
     Location firstLocation = grid.getFirstLocation();
-    Entity entity = Entity("test");
+    Entity entity = Entity(0, "test");
     firstLocation = grid.getFirstLocation();
     firstLocation.addEntity(entity);
     assert(firstLocation.getX() == 0 && firstLocation.getY() == 0);
@@ -75,8 +75,8 @@ void testRetrievingLocationAfterModification() {
 void testPlacingEntityInGrid() {
     std::cout << "---" << std::endl;
     std::cout << "Test 6 - Placing entity in grid" << std::endl;
-    Entity entity("Daniel");
-    Grid grid(4);
+    Entity entity(0, "Daniel");
+    Grid grid(0, 4);
     grid.addEntity(entity);
     assert(grid.isEntityPresent(entity));
     assert(entity.getGridId() == grid.getId());
@@ -86,8 +86,8 @@ void testPlacingEntityInGrid() {
 void testRemovingEntityFromGrid() {
     std::cout << "---" << std::endl;
     std::cout << "Test 7 - Removing entity from grid" << std::endl;
-    Entity entity("Daniel");
-    Grid grid(4);
+    Entity entity(0, "Daniel");
+    Grid grid(0, 4);
     grid.addEntity(entity);
     grid.removeEntity(entity);
     assert(!grid.isEntityPresent(entity));
@@ -98,8 +98,8 @@ void testRemovingEntityFromGrid() {
 void testPlacingEntityInEnvironment() {
     std::cout << "---" << std::endl;
     std::cout << "Test 8 - Placing entity in environment" << std::endl;
-    Entity entity("Daniel");
-    Environment environment("Earth", 2);
+    Entity entity(0, "Daniel");
+    Environment environment(0, "Earth", 2);
     environment.addEntity(entity);
     assert(environment.isEntityPresent(entity));
     assert(entity.getEnvironmentId() == environment.getId());
@@ -109,8 +109,8 @@ void testPlacingEntityInEnvironment() {
 void testRemovingEntityFromEnvironment() {
     std::cout << "---" << std::endl;
     std::cout << "Test 9 - Removing entity from environment" << std::endl;
-    Entity entity("Daniel");
-    Environment environment("Earth", 2);
+    Entity entity(0, "Daniel");
+    Environment environment(0, "Earth", 2);
     environment.addEntity(entity);
     environment.removeEntity(entity);
     assert(!environment.isEntityPresent(entity));
@@ -121,10 +121,10 @@ void testRemovingEntityFromEnvironment() {
 void testPlacingMultipleEntities() {
     std::cout << "---" << std::endl;
     std::cout << "Test 10 - Placing multiple entities" << std::endl;
-    Entity entity1("Bob");
-    Entity entity2("Phil");
-    Entity entity3("Clarisse");
-    Environment environment("Earth", 6);
+    Entity entity1(0, "Bob");
+    Entity entity2(1, "Phil");
+    Entity entity3(2, "Clarisse");
+    Environment environment(0, "Earth", 6);
     environment.addEntity(entity1);
     environment.addEntity(entity2);
     environment.addEntity(entity3);
diff --git a/tests b/tests
index 67f87b3..4084c01 100644
Binary files a/tests and b/tests differ