diff --git a/src/gui/Direction.java b/src/gui/Direction.java
deleted file mode 100644
index 15adff9..0000000
--- a/src/gui/Direction.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package gui;
-
-public enum Direction {
-    NONE,
-    UP,
-    DOWN,
-}
diff --git a/src/gui/Elevator.java b/src/gui/Elevator.java
deleted file mode 100644
index 8499815..0000000
--- a/src/gui/Elevator.java
+++ /dev/null
@@ -1,71 +0,0 @@
-package gui;
-public class Elevator {
-	private int currentFloor = 0;
-	private boolean betweenFloors = false; /* Between currentFloor and the one above it. */
-	private Direction direction = Direction.NONE;
-	private boolean stoppingNextFloor = false;
-	private boolean emergency = false;
-
-	public Elevator(int currentFloor) {
-		this.currentFloor = currentFloor;
-	}
-
-	public void goUp() {
-		if (emergency) return;
-		stoppingNextFloor = false;
-		direction = Direction.UP;
-	}
-
-	public void goDown() {
-		if (emergency) return;
-		stoppingNextFloor = false;
-		direction = Direction.DOWN;
-	}
-
-	public void stopElevator() {
-		direction = Direction.NONE;
-	}
-
-	public void stopNextFloor() {
-		stoppingNextFloor = true;
-	}
-
-	public void emergencyStop() {
-		emergency = true;
-		direction = Direction.NONE;
-	}
-
-	public void cancelEmergency() {
-		emergency = false;
-	}
-
-	public void move() {
-		if (emergency) return;
-		switch (direction) {
-		case DOWN:
-			/* Go halfway below. */
-			if (!betweenFloors) currentFloor--;
-			betweenFloors = !betweenFloors;
-			break;
-		case UP:
-			/* Go halfway above. */
-			if (betweenFloors) currentFloor++;
-			betweenFloors = !betweenFloors;
-			break;
-		default:
-			break;
-		}
-	}
-
-	public int getCurrentFloor() {
-		return currentFloor;
-	}
-
-	public boolean getBetweenFloors() {
-		return betweenFloors;
-	}
-
-	public Direction getDirection() {
-		return direction;
-	}
-}
diff --git a/src/simulation/Elevator.java b/src/simulation/Elevator.java
new file mode 100644
index 0000000..a0438d5
--- /dev/null
+++ b/src/simulation/Elevator.java
@@ -0,0 +1,127 @@
+package simulation;
+
+import java.awt.event.ActionListener;
+import java.awt.event.ActionEvent;
+
+import commandSystem.Direction;
+import commandSystem.ElevatorListener;
+
+
+public class Elevator {
+	static final int PRECISION = 10;
+	private double floorHeight;
+	private double step;
+	private double height;
+	// private int currentFloor = 0;
+	// private boolean betweenFloors = false; /* Between currentFloor and the one above it. */
+	private Direction direction = Direction.NONE;
+	private boolean stoppingNextFloor = false;
+	private boolean emergency = false;
+	private ElevatorListener listener;
+
+	public Elevator(int currentFloor, int nbFloors) {
+		height = (double) currentFloor / nbFloors;
+		floorHeight = 1. / nbFloors;
+		step = floorHeight / PRECISION;
+	}
+
+	public void setActionListener(ElevatorListener listener) {
+		this.listener = listener;
+	}
+
+	public void goUp() {
+		if (emergency) return;
+		stoppingNextFloor = false;
+		direction = Direction.UP;
+	}
+
+	public void goDown() {
+		if (emergency) return;
+		stoppingNextFloor = false;
+		direction = Direction.DOWN;
+	}
+
+	public void stopElevator() {
+		direction = Direction.NONE;
+	}
+
+	public void stopNextFloor() {
+		stoppingNextFloor = true;
+	}
+
+	public void emergencyStop() {
+		emergency = true;
+		direction = Direction.NONE;
+	}
+
+	public void cancelEmergency() {
+		emergency = false;
+	}
+
+	public void update() {
+		if (emergency) return;
+		int prevFloor = (int) Math.floor(height / floorHeight);
+		switch (direction) {
+		case DOWN:
+			height -= step;
+
+			/* Bottom reached. */
+			if (height < step) {
+				height = 0;
+				direction = Direction.NONE;
+			}
+
+			/* Passed a floor, invoke the listener. */
+			if (Math.floor(height / floorHeight) < prevFloor && listener != null) {
+				listener.floorChange(Direction.UP);
+			}
+			// /* Go halfway below. */
+			// if (!betweenFloors) currentFloor--;
+			// betweenFloors = !betweenFloors;
+			break;
+		case UP:
+			height += step;
+
+			/* Top reached. */
+			if (height > 1-step) {
+				height = 1;
+				direction = Direction.NONE;
+			}
+
+			/* Passed a floor, invoke the listener. */
+			if (Math.floor(height / floorHeight) < prevFloor && listener != null) {
+				listener.floorChange(Direction.DOWN);
+			}
+			// /* Go halfway above. */
+			// if (betweenFloors) currentFloor++;
+			// betweenFloors = !betweenFloors;
+			break;
+		default:
+			break;
+		}
+	}
+
+	// public int getCurrentFloor() {
+	// 	return currentFloor;
+	// }
+
+	// public boolean getBetweenFloors() {
+	// 	return betweenFloors;
+	// }
+
+	public Direction getDirection() {
+		return direction;
+	}
+
+	public boolean getStoppingNextFloor() {
+		return stoppingNextFloor;
+	}
+
+	public double getHeight() {
+		return height;
+	}
+
+	public boolean getEmergency() {
+		return emergency;
+	}
+}
diff --git a/src/simulation/Simulation.java b/src/simulation/Simulation.java
new file mode 100644
index 0000000..f8884bc
--- /dev/null
+++ b/src/simulation/Simulation.java
@@ -0,0 +1,63 @@
+package simulation;
+
+import Requests.CallFromElevatorRequest;
+import Requests.CallFromFloorRequest;
+
+import commandSystem.EventQueue;
+import commandSystem.Direction;
+import commandSystem.ElevatorListener;
+import simulation.Elevator;
+
+
+public class Simulation implements ElevatorListener {
+	private boolean running = false;
+	private int currentFloor = 0;
+	private EventQueue queue;
+	private Elevator elevator;
+
+	public Simulation(Elevator elevator) {
+		this.elevator = elevator;
+	}
+
+	public void elevatorCall(int floor) {
+	}
+
+	public void floorCall(int floor, Direction direction) {
+	}
+
+	public void floorChange(Direction d) {
+		switch (d) {
+		case UP:
+			currentFloor++;
+			break;
+		case DOWN:
+			currentFloor--;
+			break;
+		}
+		// iter();
+	}
+
+	// public void iter() {
+	// 	int nextDestination = queue.getNextInstruction();
+	// 	int currentFloor = 0;
+	// 	//System.out.println("next dest = " + nextDestination);
+	// 	if (!running) {
+	// 		if (nextDestination > 0) { /* We have a destination to go to. */
+	// 			running = true;
+	// 			elevator.goDown();
+	// 		}
+	// 	}
+	// 	else {
+	// 		if (elevator.currentFloor == nextDestination) {
+	// 			queue.removeInstruction(elevator.currentFloor, elevator.direction);
+	// 			running = false;
+	// 		}
+	// 		else {
+	// 			elevator.direction = elevator.currentFloor < nextDestination ? Direction.UP : Direction.DOWN;
+	// 			elevator.currentFloor += elevator.direction == Direction.UP ? 1 : -1;
+	// 		}
+	// 	}
+	// 	System.out.println("elevator floor " + elevator.currentFloor + " direction " +
+	// 		(elevator.direction == Direction.UP? "up" : "down") + " running: " + running);
+	// }
+}