diff --git a/lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/personcomputer/Computer.java b/lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/personcomputer/Computer.java
new file mode 100644
index 000000000..cc2541683
--- /dev/null
+++ b/lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/personcomputer/Computer.java
@@ -0,0 +1,94 @@
+package com.codedifferently.lesson16.personcomputer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Computer {
+  public enum ComputerStatus {
+    OFFLINE,
+    ONLINE,
+    SLEEP,
+    SHUTDOWN
+  }
+
+  private String brand;
+  private String model;
+  private String cpu;
+  private int ramGB;
+  private int storageGB;
+  private boolean isPoweredOn;
+  private List<String> installedPrograms;
+  private ComputerStatus status; // use the enum here
+
+  public Computer(
+      String brand, String model, String cpu, int ramGB, int storageGB, String installedPrograms) {
+    this.brand = brand;
+    this.model = model;
+    this.cpu = cpu;
+    this.ramGB = ramGB;
+    this.storageGB = storageGB;
+    this.isPoweredOn = false;
+    this.installedPrograms = new ArrayList<>();
+    this.status = ComputerStatus.OFFLINE;
+  }
+
+  public class ComputerAlreadyOnException extends Exception {
+    public ComputerAlreadyOnException(String message) {
+      super(message);
+    }
+  }
+
+  public void powerOn() throws ComputerAlreadyOnException {
+    if (!isPoweredOn) {
+      isPoweredOn = true;
+      status = ComputerStatus.ONLINE;
+    } else {
+      throw new ComputerAlreadyOnException("Computer is already powered on.");
+    }
+  }
+
+  public String getBrand() {
+    return brand;
+  }
+
+  public String getModel() {
+    return model;
+  }
+
+  public String getCPU() {
+    return cpu;
+  }
+
+  public int getRAMGB() {
+    return ramGB;
+  }
+
+  public int getSTORAGEGB() {
+    return storageGB;
+  }
+
+  public boolean isPoweredOn() {
+    return isPoweredOn;
+  }
+
+  public ComputerStatus getStatus() {
+    return status;
+  }
+
+  public void listPrograms() {
+    System.out.println("Installed Programs:");
+    for (String program : installedPrograms) {
+      System.out.println("- " + program);
+    }
+  }
+
+  public void installProgram(String programName) {
+    if (!installedPrograms.contains(programName)) {
+      installedPrograms.add(programName);
+    }
+  }
+
+  public List<String> getInstalledPrograms() {
+    return installedPrograms;
+  }
+}
diff --git a/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerAlreadyOnException.java b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerAlreadyOnException.java
new file mode 100644
index 000000000..26a54798f
--- /dev/null
+++ b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerAlreadyOnException.java
@@ -0,0 +1,28 @@
+package com.codedifferently.lesson16.personcomputer;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class ComputerAlreadyOnExceptionTest {
+
+  @Test
+  void testExceptionMessage() {
+    String message = "Computer is already powered on.";
+    Computer.ComputerAlreadyOnException exception =
+        new Computer(message, message, message, 0, 0, message)
+        .new ComputerAlreadyOnException(message);
+    assertEquals(message, exception.getMessage());
+  }
+
+  @Test
+  void testPowerOnThrowsException() throws Exception {
+    Computer computer = new Computer("Dell", "XPS", "Intel", 8, 256, "");
+    computer.powerOn();
+
+    Exception exception =
+        assertThrows(Computer.ComputerAlreadyOnException.class, computer::powerOn);
+
+    assertEquals("Computer is already powered on.", exception.getMessage());
+  }
+}
diff --git a/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerStatusTest.java b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerStatusTest.java
new file mode 100644
index 000000000..606455aea
--- /dev/null
+++ b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerStatusTest.java
@@ -0,0 +1,28 @@
+package com.codedifferently.lesson16.personcomputer;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class ComputerStatusTest {
+
+  @Test
+  void testEnumValues() {
+    Computer.ComputerStatus[] statuses = Computer.ComputerStatus.values();
+    assertEquals(4, statuses.length);
+    assertArrayEquals(
+        new Computer.ComputerStatus[] {
+          Computer.ComputerStatus.OFFLINE,
+          Computer.ComputerStatus.ONLINE,
+          Computer.ComputerStatus.SLEEP,
+          Computer.ComputerStatus.SHUTDOWN
+        },
+        statuses);
+  }
+
+  @Test
+  void testValueOf() {
+    assertEquals(Computer.ComputerStatus.ONLINE, Computer.ComputerStatus.valueOf("ONLINE"));
+  }
+}
diff --git a/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerTest.java b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerTest.java
new file mode 100644
index 000000000..3aed1da33
--- /dev/null
+++ b/lesson_16/objects/objects_app/src/test/java/com/codedifferently/lesson16/personcomputer/ComputerTest.java
@@ -0,0 +1,58 @@
+package com.codedifferently.lesson16.personcomputer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class ComputerTest {
+
+  private Computer computer;
+
+  @BeforeEach
+  public void setUp() {
+    computer = new Computer("Dell", "Inspiron 15", "Intel Core i7", 16, 512, "Windows 11");
+  }
+
+  @Test
+  public void testPowerOn() throws Computer.ComputerAlreadyOnException {
+    assertFalse(computer.isPoweredOn());
+
+    computer.powerOn();
+
+    assertTrue(computer.isPoweredOn());
+    assertEquals(Computer.ComputerStatus.ONLINE, computer.getStatus());
+  }
+
+  @Test
+  public void testInstallProgram() {
+    // Install a new program
+    computer.installProgram("Windows 11");
+
+    assertTrue(computer.getInstalledPrograms().contains("Windows 11"));
+  }
+
+  @Test
+  public void testDuplicateProgramNotInstalledTwice() {
+    // Install a program
+    computer.installProgram("Google Chrome");
+
+    // Try installing the same program again
+    computer.installProgram("Google Chrome");
+
+    // Verify the program is only installed once
+    assertEquals(1, computer.getInstalledPrograms().size());
+  }
+
+  @Test
+  public void testGetters() {
+    // Verify that the getters return correct values
+    assertEquals("Dell", computer.getBrand());
+    assertEquals("Inspiron 15", computer.getModel());
+    assertEquals("Intel Core i7", computer.getCPU());
+    assertEquals(16, computer.getRAMGB());
+    assertEquals(512, computer.getSTORAGEGB());
+  }
+}