diff --git a/doc/classes.puml b/doc/classes.puml
new file mode 100644
index 0000000..9629917
--- /dev/null
+++ b/doc/classes.puml
@@ -0,0 +1,70 @@
+@startuml
+
+' Base class
+class SystemElement {
+    - string name
+    + SystemElement(string name)
+}
+
+' Template container class
+class SystemElementContainer<T> {
+    - unsigned int iter_count
+    - unordered_map<string, T*> content
+    + SystemElementContainer(string name)
+    + SystemElementContainer(string name, vector<T*> elements)
+    + bool exists(string name)
+    + void add(T* element)
+    + void add(SystemElementContainer<T>* elements)
+    + void add(vector<T*> elements)
+    + T* get(string name)
+    + T* merge(string name)
+    + iterator begin()
+    + iterator end()
+    + const_iterator begin() const
+    + const_iterator end() const
+}
+
+SystemElementContainer --|> SystemElement
+
+' Part and Pin classes
+class Part {
+    + Part(string name)
+    + void add(Pin* pin)
+}
+
+class Pin {
+    + Pin(string name)
+    + void connect(Signal* signal)
+}
+
+Part --* Pin
+
+' Signal class
+class Signal {
+    + Signal(string name)
+    + void connect(Pin* pin)
+}
+
+Pin --> Signal
+
+' Module and Modules classes
+class Module {
+    + Signals* signals
+    + Modules* prnt
+    + Module(string name)
+    + ~Module()
+}
+
+class Modules {
+    + Modules()
+    + Modules(vector<Module*> parts)
+    + void add(Module* module)
+    + ~Modules()
+}
+
+Module --|> SystemElementContainer
+Modules --|> SystemElementContainer
+Module --> Modules
+Module --> Signals
+
+@enduml
diff --git a/src/imports/import_mentor.cpp b/src/imports/import_mentor.cpp
index 90c46d5..bacdd3d 100644
--- a/src/imports/import_mentor.cpp
+++ b/src/imports/import_mentor.cpp
@@ -106,7 +106,9 @@ void ImportMentor::parse(Signals *signals)
                     auto pin = new Pin(names[0]); // Create a new pin with the first name.
                     Signal *s = nullptr;
                     prt->add(pin); // Add the pin to the current part.
-                    pin->connect(signals->merge(names[2])); // Connect the pin to a signal.
+                    s = signals->merge(names[2]); // Merge the signal with module signals.
+                    s->add(pin); // Add the pin to the signal pins list.
+                    pin->connect(s); // Connect the pin to a signal.
                 }
             }
             break;
diff --git a/src/main.cpp b/src/main.cpp
index a8fad52..ba7d9c3 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3,8 +3,9 @@
 using namespace std;
 
 int main() {
-    System sys = System();
+    System *sys = new System();
     string ment_filename = "/home/francois/Projets/twinsys/test/BPB-2177_Netlist_2_3.qcv";
 
-    sys.Load("bpb", ment_filename, ImportType::IMPORT_MENTOR);
+    sys->Load("bpb", ment_filename, ImportType::IMPORT_MENTOR);
+    delete sys;
 };
diff --git a/src/system/modules.cpp b/src/system/modules.cpp
index 343f64c..f2a3390 100644
--- a/src/system/modules.cpp
+++ b/src/system/modules.cpp
@@ -1,7 +1,30 @@
 #include "modules.hpp"
 
-Module::Module(std::string name) : SystemElementContainer<Part>(name) {}
+#include "signals.hpp"
+
+Module::Module(std::string name) : SystemElementContainer<Part>(name), prnt(nullptr) {
+    signals = new Signals();
+}
+
+Module::~Module() {
+    for (const auto& [key, value] : content) {
+        delete value;
+    }
+    delete signals;
+}
 
 Modules::Modules(void): SystemElementContainer<Module>("modules") {}
 
-Modules::Modules(std::vector<Module *> modules): SystemElementContainer<Module>("modules", modules) {}
\ No newline at end of file
+Modules::Modules(std::vector<Module *> modules): SystemElementContainer<Module>("modules", modules) {}
+
+void Modules::add(Module *module)
+{
+    SystemElementContainer<Module>::add(module);
+    module->prnt = this;
+}
+
+Modules::~Modules() {
+    for (const auto& [key, value] : content) {
+        delete value;
+    }
+}
\ No newline at end of file
diff --git a/src/system/modules.hpp b/src/system/modules.hpp
index 935133a..4687a2f 100644
--- a/src/system/modules.hpp
+++ b/src/system/modules.hpp
@@ -3,20 +3,28 @@
 
 #include "syselmts.hpp"
 #include "parts.hpp"
-#include "signals.hpp"
+
+#pragma once
+class Modules; ///< Forward declaration of the Modules class.
+class Signals; ///< Forward declaration of the Signals class.
+
 
 class Module : public SystemElementContainer<Part>
 {
 public:
-    Signals sigs;
+    Signals *signals;
+    Modules *prnt;
     Module(std::string name);
+    ~Module();
 };
 
 class Modules : public SystemElementContainer<Module>
 {
 public:
     Modules(void);
-    Modules(std::vector<Module *> pins);
+    Modules(std::vector<Module *> parts);
+    void add(Module *module);
+    ~Modules();
 };
 
 #endif // _MODULES_HPP_
\ No newline at end of file
diff --git a/src/system/parts.cpp b/src/system/parts.cpp
index 8542c20..41ac50f 100644
--- a/src/system/parts.cpp
+++ b/src/system/parts.cpp
@@ -1,7 +1,19 @@
 #include "parts.hpp"
 
-Part::Part(std::string name) : SystemElementContainer<Pin>(name) {};
+Part::Part(std::string name) : SystemElementContainer<Pin>(name), prnt(nullptr) {};
+
+void Part::add(Pin *pin)
+{
+    SystemElementContainer<Pin>::add(pin);
+    pin->prnt = this;
+}
+
+Part::~Part() {
+    for (const auto& [key, value] : content) {
+        delete value;
+    }
+}
 
 Parts::Parts(void): SystemElementContainer<Part>("parts") {}
 
-Parts::Parts(std::vector<Part *> parts): SystemElementContainer<Part>("parts", parts) {}
\ No newline at end of file
+Parts::Parts(std::vector<Part *> parts): SystemElementContainer<Part>("parts", parts) {}
diff --git a/src/system/parts.hpp b/src/system/parts.hpp
index d3485d1..ba3deae 100644
--- a/src/system/parts.hpp
+++ b/src/system/parts.hpp
@@ -4,10 +4,16 @@
 #include "syselmts.hpp"
 #include "pins.hpp"
 
+#pragma once
+class Module; ///< Forward declaration of the Module class.
+
 class Part : public SystemElementContainer<Pin>
 {
 public:
     Part(std::string name);
+    ~Part();
+    Module *prnt; ///< Pointer to the parent module.
+    void add(Pin *pin) override;
 };
 
 class Parts : public SystemElementContainer<Part>
diff --git a/src/system/pins.cpp b/src/system/pins.cpp
index fa4fb6a..64a1b50 100644
--- a/src/system/pins.cpp
+++ b/src/system/pins.cpp
@@ -1,8 +1,11 @@
 #include "pins.hpp"
+#include "parts.hpp"
+#include "signals.hpp"
 
-Pin::Pin(std::string name) : SystemElement(name), sig(nullptr) {};
+Pin::Pin(std::string name) : SystemElement(name), sig(nullptr), prnt(nullptr) {};
 
-bool Pin::connected() {
+bool Pin::connected()
+{
     return sig != nullptr;
 }
 
@@ -11,6 +14,6 @@ void Pin::connect(Signal *signal)
     sig = signal;
 }
 
-Pins::Pins(void): SystemElementContainer<Pin>("pins") {}
+Pins::Pins(void) : SystemElementContainer<Pin>("pins") {}
 
-Pins::Pins(std::vector<Pin *> pins): SystemElementContainer<Pin>("pins", pins) {}
\ No newline at end of file
+Pins::Pins(std::vector<Pin *> pins) : SystemElementContainer<Pin>("pins", pins) {}
\ No newline at end of file
diff --git a/src/system/pins.hpp b/src/system/pins.hpp
index dfa3169..fe51d76 100644
--- a/src/system/pins.hpp
+++ b/src/system/pins.hpp
@@ -2,13 +2,19 @@
 #define _PINS_HPP_
 
 #include "syselmts.hpp"
-#include "signals.hpp"
+
+#pragma once
+class Part;
+
+#pragma once
+class Signal;
 
 class Pin : public SystemElement
 {
     Signal *sig;
 public:
     Pin(std::string name);
+    Part *prnt; ///< Pointer to the parent part.
     bool connected();
     void connect(Signal *signal);
 };
diff --git a/src/system/signals.cpp b/src/system/signals.cpp
index 80071c9..cdea7d2 100644
--- a/src/system/signals.cpp
+++ b/src/system/signals.cpp
@@ -1,11 +1,27 @@
 
 #include "signals.hpp"
+#include "parts.hpp"
 
-Signal::Signal(std::string name) : SystemElementContainer<Pin>(name) {};
+Signal::Signal(std::string name) : SystemElementContainer<Pin>(name), prnt(nullptr) {};
+
+void Signal::add(Pin *pin)
+{
+    string pname = pin->prnt->name + "." + pin->name;
+    SystemElementContainer<Pin>::add(pname, pin);
+}
 
 Signals::Signals(void): SystemElementContainer<Signal>("signals") {}
 
 Signals::Signals(std::vector<Signal *> signals): SystemElementContainer<Signal>("signals", signals) {}
 
-Signals::~Signals() {}
+Signals::~Signals() {
+    for (const auto& [key, value] : content) {
+        delete value;
+    }
+}
 
+void Signals::add(Signal *signal)
+{
+    SystemElementContainer<Signal>::add(signal);
+    signal->prnt = this;
+}
\ No newline at end of file
diff --git a/src/system/signals.hpp b/src/system/signals.hpp
index 2daeb11..dac0233 100644
--- a/src/system/signals.hpp
+++ b/src/system/signals.hpp
@@ -2,14 +2,17 @@
 #define _SIGNALS_HPP_
 
 #include "syselmts.hpp"
+#include "pins.hpp"
 
 #pragma once
-class Pin;
+class Signals;
 
 class Signal : public SystemElementContainer<Pin>
 {
 public:
+    Signals *prnt; ///< Pointer to the parent signals object.
     Signal(std::string name);
+    void add(Pin *pin) override;
 };
 
 class Signals : public SystemElementContainer<Signal>
@@ -17,6 +20,7 @@ class Signals : public SystemElementContainer<Signal>
 public:
     Signals(void);
     Signals(std::vector<Signal *> signals);
+    void add(Signal *signal) override;
     ~Signals();
 };
 
diff --git a/src/system/syselmts.hpp b/src/system/syselmts.hpp
index 92a7259..cf3625f 100644
--- a/src/system/syselmts.hpp
+++ b/src/system/syselmts.hpp
@@ -32,13 +32,13 @@ template <typename T>
 class SystemElementContainer : public SystemElement
 {
 public:
-    using MapType = unordered_map<string, T *>; // Map to store elements by name.
-    using iterator = typename MapType::iterator; // Iterator for the map.
+    using MapType = unordered_map<string, T *>;              // Map to store elements by name.
+    using iterator = typename MapType::iterator;             // Iterator for the map.
     using const_iterator = typename MapType::const_iterator; // Const iterator for the map.
 
-private:
+protected:
     unsigned int iter_count; // Counter for iterations (currently unused).
-    MapType content; // Container for storing elements.
+    MapType content;         // Container for storing elements.
 
     /**
      * @brief Adds elements from a map to the container.
@@ -69,6 +69,35 @@ public:
         add(elements);
     }
 
+    /**
+     * @brief Adds a single element to the container with a given name.
+     * @param name Name of the element to add.
+     * @param element Pointer to the element to add.
+     * @throws runtime_error If the element's name is empty or already exists.
+     */
+    virtual void add(string name, T *element)
+    {
+        if ("" == name)
+        {
+            throw runtime_error("System elements with empty names are forbidden");
+        }
+        if (exists(name))
+        {
+            throw runtime_error("System elements of same names are forbidden");
+        }
+        content.insert({name, element});
+    }
+
+    /**
+     * @brief Adds a single element to the container.
+     * @param element Pointer to the element to add.
+     * @throws runtime_error If the element's name is empty or already exists.
+     */
+    virtual void add(T *element)
+    {
+        add (element->name, element);
+    }
+
     /**
      * @brief Checks if an element exists in the container.
      * @param name Name of the element to check.
@@ -87,24 +116,6 @@ public:
         }
     }
 
-    /**
-     * @brief Adds a single element to the container.
-     * @param element Pointer to the element to add.
-     * @throws runtime_error If the element's name is empty or already exists.
-     */
-    void add(T *element)
-    {
-        if ("" == element->name)
-        {
-            throw runtime_error("System elements with empty names are forbidden");
-        }
-        if (exists(element->name))
-        {
-            throw runtime_error("System elements of same names are forbidden");
-        }
-        content.insert({element->name, element});
-    }
-
     /**
      * @brief Adds elements from another container.
      * @param elements Pointer to another container.
@@ -150,14 +161,15 @@ public:
      * @param name Name of the element.
      * @return Pointer to the merged or newly created element.
      */
-    T* merge(string name)
+    T *merge(string name)
     {
-        if (exists(name)) {
+        if (exists(name))
+        {
             return get(name);
         }
         else
         {
-            T* ret = new T(name);
+            T *ret = new T(name);
             add(ret);
             return ret;
         }
@@ -167,25 +179,25 @@ public:
      * @brief Returns an iterator to the beginning of the container.
      * @return Iterator to the beginning.
      */
-    iterator begin() { return content.begin(); }
+    iterator begin() { return std::begin(content); }
 
     /**
      * @brief Returns an iterator to the end of the container.
      * @return Iterator to the end.
      */
-    iterator end() { return content.end(); }
+    iterator end() { return std::end(content); }
 
     /**
      * @brief Returns a constant iterator to the beginning of the container.
      * @return Constant iterator to the beginning.
      */
-    const_iterator begin() const { return content.begin(); }
+    const_iterator begin() const { return std::begin(content); }
 
     /**
      * @brief Returns a constant iterator to the end of the container.
      * @return Constant iterator to the end.
      */
-    const_iterator end() const { return content.end(); }
+    const_iterator end() const { return std::end(content); }
 };
 
 #endif
\ No newline at end of file
diff --git a/src/system/system.cpp b/src/system/system.cpp
index d0f2e34..a92fb4a 100644
--- a/src/system/system.cpp
+++ b/src/system/system.cpp
@@ -1,28 +1,43 @@
 
 #include "system.hpp"
+
+#include "connect.hpp"
+#include "modules.hpp"
 #include "imports/import_mentor.hpp"
 
-System::System(): mods(nullptr), conns(nullptr) {
+System::System() : mods(nullptr), conns(nullptr)
+{
     mods = new Modules();
     conns = new Connections();
 }
 
-System::~System() {
+System::~System()
+{
     delete mods;
     delete conns;
 }
 
-void System::Load(std::string module_name, std::string file_name, ImportType type) {
+void System::Load(std::string module_name, std::string file_name, ImportType type)
+{
     ImportBase *imp;
+    Module *mod = nullptr;
     Parts *prts = nullptr;
-    Module mod = Module(module_name);
+    if (!mods->exists(module_name))
+    {
+        mod = new Module(module_name);
+        mods->add(mod);
+    }
+    else
+    {
+        mod = mods->get(module_name);
+    }
     switch (type)
     {
-    case ImportType::IMPORT_MENTOR :
+    case ImportType::IMPORT_MENTOR:
         imp = new ImportMentor(file_name);
-        imp->parse();
+        imp->parse(mod->signals);
         prts = imp->parts();
-        mod.add(prts);
+        mod->add(prts);
         break;
 
     default:
diff --git a/src/system/system.hpp b/src/system/system.hpp
index ed391c2..ea4e965 100644
--- a/src/system/system.hpp
+++ b/src/system/system.hpp
@@ -1,8 +1,12 @@
 #ifndef _SYSTEM_HPP_
 #define _SYSTEM_HPP_
 
-#include "connect.hpp"
-#include "modules.hpp"
+#include "imports/import_base.hpp"
+
+#pragma once
+class Modules; ///< Forward declaration of the Modules class.
+class Connections; ///< Forward declaration of the Connections class.
+
 
 enum class ImportType {
     IMPORT_MENTOR,