diff --git a/Cargo.lock b/Cargo.lock
index 9898199..e3bcbe3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6,16 +6,9 @@ version = 3
 name = "burritos"
 version = "0.1.0"
 dependencies = [
- "lazy_static",
  "libc",
 ]
 
-[[package]]
-name = "lazy_static"
-version = "1.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
-
 [[package]]
 name = "libc"
 version = "0.2.139"
diff --git a/Cargo.toml b/Cargo.toml
index d9e3b00..1d66884 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,5 +4,4 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-lazy_static = "1.4.0"
 libc = { version = "0.2.139", features = ["extra_traits"] }
diff --git a/src/kernel/system.rs b/src/kernel/system.rs
index 1fd2de9..b0f54c8 100644
--- a/src/kernel/system.rs
+++ b/src/kernel/system.rs
@@ -1,19 +1,87 @@
-use std::{sync::{RwLock, Arc}};
+use std::rc::Rc;
+use crate::{
+    kernel::{
+        thread::Thread,
+        scheduler::Scheduler
+    },
+    utility::list::List,
+    simulator::machine::Machine
+};
 
-use lazy_static::lazy_static;
-
-use crate::{kernel::{thread::Thread, scheduler::Scheduler}, utility::list::List, simulator::machine::Machine};
-
-extern crate lazy_static;
-
-lazy_static! {
-    pub static ref G_MACHINE: RwLock<Machine> = RwLock::new(Machine::_init_machine());
-    pub static ref G_CURRENT_THREAD: RwLock<Option<Thread>> = RwLock::new(Option::None);
-    pub static ref G_THREAD_TO_BE_DESTROYED: RwLock<Option<Thread>> = RwLock::new(Option::None);
-    pub static ref G_ALIVE: RwLock<List<Arc<Thread>>> = RwLock::new(List::new());
-    pub static ref G_SCHEDULER: RwLock<Scheduler> = RwLock::new(Scheduler::new());
+/// # System
+/// 
+/// This structure represents the state of the threads running on the operating system.
+/// It contains references to the following:
+/// 
+/// - The simulated machine
+/// - The current running thread
+/// - The list of active threads
+/// - The thread to be destroyed next
+/// - The scheduler which acts upon these threads
+pub struct System {
+    g_machine: Machine,
+    g_current_thread: Option<Thread>,
+    g_thread_to_be_destroyed: Option<Thread>,
+    g_alive: List<Rc<Thread>>,
+    g_scheduler: Scheduler
 }
 
+impl System {
+
+    // GETTERS
+
+    /// Returns the Machine
+    /// 
+    /// Useful to access RAM, devices, ...
+    pub fn get_g_machine(&mut self) -> &mut Machine {
+        &mut self.g_machine
+    }
+
+    /// Currently running thread
+    pub fn get_g_current_thread(&mut self) -> &mut Option<Thread> {
+        &mut self.g_current_thread
+    }
+
+    /// Thread to be destroyed by [...]
+    /// 
+    /// TODO: Finish the comment with the relevant value
+    pub fn get_g_thread_to_be_destroyed(&mut self) -> &mut Option<Thread> {
+        &mut self.g_thread_to_be_destroyed
+    }
+
+    /// List of alive threads
+    pub fn get_g_alive(&mut self) -> &mut List<Rc<Thread>> {
+        &mut self.g_alive
+    }
+
+    /// Current scheduler
+    pub fn g_scheduler(&mut self) -> &mut Scheduler {
+        &mut self.g_scheduler
+    }
+
+    // Setters
+
+    /// Assign a machine to the system
+    pub fn set_g_machine(&mut self, machine: Machine) {
+        self.g_machine = machine
+    }
+
+    /// Set currently running thread
+    pub fn set_g_current_thread(&mut self, thread: Option<Thread>) {
+        self.g_current_thread = thread
+    }
+
+    /// Set thread to be destroyed next
+    pub fn set_g_thread_to_be_destroyed(&mut self, thread: Option<Thread>) {
+        self.g_thread_to_be_destroyed = thread
+    }
+
+    /// Set Scheduler which will manage the threads
+    pub fn set_g_scheduler(&mut self, scheduler: Scheduler) {
+        self.g_scheduler = scheduler
+    }
+
+}
 
 #[derive(PartialEq)]
 pub enum ObjectType {