diff --git a/.forge/BAIS-POLICY-1783705261-attempt-1.md b/.forge/BAIS-POLICY-1783705261-attempt-3.md
similarity index 60%
rename from .forge/BAIS-POLICY-1783705261-attempt-1.md
rename to .forge/BAIS-POLICY-1783705261-attempt-3.md
index 53daa39..9f2d8e5 100644
--- a/.forge/BAIS-POLICY-1783705261-attempt-1.md
+++ b/.forge/BAIS-POLICY-1783705261-attempt-3.md
@@ -1,3 +1,3 @@
-# BAIS-POLICY-1783705261-attempt-1
+# BAIS-POLICY-1783705261-attempt-3
 
-Forge 이슈 작업 브랜치 `forge/BAIS-POLICY-1783705261-attempt-1`.
+Forge 이슈 작업 브랜치 `forge/BAIS-POLICY-1783705261-attempt-3`.
diff --git a/pom.xml b/pom.xml
new file mode 100644
index 0000000..1d4db07
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,39 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.example.baispolicy</groupId>
+    <artifactId>bais-policy</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>3.5.14</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+
+    <properties>
+        <java.version>17</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+</project>
diff --git a/src/main/java/com/example/baispolicy/PaymentService.java b/src/main/java/com/example/baispolicy/PaymentService.java
index f5f9ae7..420d154 100644
--- a/src/main/java/com/example/baispolicy/PaymentService.java
+++ b/src/main/java/com/example/baispolicy/PaymentService.java
@@ -3,8 +3,8 @@ package com.example.baispolicy;
 public class PaymentService {
     public String approve(String transactionId) {
         if (transactionId == null || transactionId.isBlank()) {
-            throw new IllegalArgumentException("Transaction ID cannot be blank");
+            throw new IllegalArgumentException("Transaction ID must not be blank.");
         }
         return "APPROVED:" + transactionId;
     }
-}
\ No newline at end of file
+}
diff --git a/src/test/java/com/example/baispolicy/PaymentServiceTest.java b/src/test/java/com/example/baispolicy/PaymentServiceTest.java
new file mode 100644
index 0000000..e29ee02
--- /dev/null
+++ b/src/test/java/com/example/baispolicy/PaymentServiceTest.java
@@ -0,0 +1,25 @@
+package com.example.baispolicy;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class PaymentServiceTest {
+    private final PaymentService paymentService = new PaymentService();
+
+    @Test
+    void testApprove_WithValidTransactionId_ShouldReturnApprovedMessage() {
+        String transactionId = "12345";
+        String result = paymentService.approve(transactionId);
+        assertEquals("APPROVED:12345", result);
+    }
+
+    @Test
+    void testApprove_WithBlankTransactionId_ShouldThrowException() {
+        assertThrows(IllegalArgumentException.class, () -> {
+            paymentService.approve("");
+        });
+        assertThrows(IllegalArgumentException.class, () -> {
+            paymentService.approve(null);
+        });
+    }
+}