diff --git a/testing-modules/pom.xml b/testing-modules/pom.xml
index a6b5fba570..9080d5a0ea 100644
--- a/testing-modules/pom.xml
+++ b/testing-modules/pom.xml
@@ -52,6 +52,7 @@
         <module>xmlunit-2</module>
         <module>zerocode</module>
         <module>mockito-2</module>
+        <module>testing-techniques</module>
         <module>gatling-java</module>
     </modules>
 
diff --git a/testing-modules/testing-techniques/pom.xml b/testing-modules/testing-techniques/pom.xml
new file mode 100644
index 0000000000..5902047aeb
--- /dev/null
+++ b/testing-modules/testing-techniques/pom.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+
+    <artifactId>testing-techniques</artifactId>
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <artifactId>testing-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+</project>
\ No newline at end of file
diff --git a/testing-modules/testing-techniques/src/main/java/com/baeldung/greyboxtesting/SalaryCommissionPercentageCalculator.java b/testing-modules/testing-techniques/src/main/java/com/baeldung/greyboxtesting/SalaryCommissionPercentageCalculator.java
new file mode 100644
index 0000000000..d97b6687b3
--- /dev/null
+++ b/testing-modules/testing-techniques/src/main/java/com/baeldung/greyboxtesting/SalaryCommissionPercentageCalculator.java
@@ -0,0 +1,67 @@
+package com.baeldung.greyboxtesting;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.stream.DoubleStream;
+
+public class SalaryCommissionPercentageCalculator {
+    public BigDecimal calculate(Level level, Type type, Seniority seniority, SalesImpact impact) {
+        return BigDecimal.valueOf(DoubleStream.of(level.getBonus(), type.getBonus(), seniority.getBonus(), impact.getBonus(), type.getBonus())
+                .average()
+                .orElse(0))
+                .setScale(2, RoundingMode.CEILING);
+    }
+
+    public enum Level {
+        L1(0.06), L2(0.12), L3(0.2);
+        private double bonus;
+
+        Level(double bonus) {
+            this.bonus = bonus;
+        }
+
+        public double getBonus() {
+            return bonus;
+        }
+    }
+
+    public enum Type {
+        FULL_TIME_COMMISSIONED(0.18), CONTRACTOR(0.1), FREELANCER(0.06);
+
+        private double bonus;
+
+        Type(double bonus) {
+            this.bonus = bonus;
+        }
+
+        public double getBonus() {
+            return bonus;
+        }
+    }
+
+    public enum Seniority {
+        JR(0.8), MID(0.13), SR(0.19);
+        private double bonus;
+
+        Seniority(double bonus) {
+            this.bonus = bonus;
+        }
+
+        public double getBonus() {
+            return bonus;
+        }
+    }
+
+    public enum SalesImpact {
+        LOW(0.06), MEDIUM(0.12), HIGH(0.2);
+        private double bonus;
+
+        SalesImpact(double bonus) {
+            this.bonus = bonus;
+        }
+
+        public double getBonus() {
+            return bonus;
+        }
+    }
+}
diff --git a/testing-modules/testing-techniques/src/test/java/com/baeldung/greyboxtesting/SalaryCommissionPercentageCalculatorUnitTest.java b/testing-modules/testing-techniques/src/test/java/com/baeldung/greyboxtesting/SalaryCommissionPercentageCalculatorUnitTest.java
new file mode 100644
index 0000000000..e39a1e5445
--- /dev/null
+++ b/testing-modules/testing-techniques/src/test/java/com/baeldung/greyboxtesting/SalaryCommissionPercentageCalculatorUnitTest.java
@@ -0,0 +1,41 @@
+package com.baeldung.greyboxtesting;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.math.BigDecimal;
+import java.util.stream.Stream;
+
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.Level.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.SalesImpact.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.Seniority.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.Type.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class SalaryCommissionPercentageCalculatorUnitTest {
+
+    private SalaryCommissionPercentageCalculator testTarget = new SalaryCommissionPercentageCalculator();
+
+    @ParameterizedTest
+    @MethodSource("provideReferenceTestScenarioTable")
+    void givenReferenceTable_whenCalculateAverageCommission_thenReturnExpectedResult(Level level, Type type, Seniority seniority, SalesImpact impact, double expected) {
+        BigDecimal got = testTarget.calculate(level, type, seniority, impact);
+        assertEquals(BigDecimal.valueOf(expected), got);
+    }
+
+    private static Stream<Arguments> provideReferenceTestScenarioTable() {
+        return Stream.of(
+                Arguments.of(L1, FULL_TIME_COMMISSIONED, JR, LOW, 0.26),
+                Arguments.of(L1, CONTRACTOR, SR, MEDIUM, 0.12),
+                Arguments.of(L1, FREELANCER, MID, HIGH, 0.11),
+                Arguments.of(L2, FULL_TIME_COMMISSIONED, SR, HIGH, 0.18),
+                Arguments.of(L2, CONTRACTOR, MID, LOW, 0.11),
+                Arguments.of(L2, FREELANCER, JR, MEDIUM, 0.24),
+                Arguments.of(L3, FULL_TIME_COMMISSIONED, MID, MEDIUM, 0.17),
+                Arguments.of(L3, CONTRACTOR, JR, HIGH, 0.28),
+                Arguments.of(L3, FREELANCER, SR, LOW, 0.12)
+        );
+    }
+}
\ No newline at end of file