Coffee Vending Machine Test Cases

This tutorial outlines sample test cases for a simple coffee vending machine. Coffee machine can provide many features for the customer. We will stick to a basic machine in this example.

Machine Components

Let’s look into some of the important Coffee machine components to understand the system better. A better understanding of the system under test yields effective test cases.

• Machine Body
• Smart card reader
• Motor
• Microcontroller
• Water heating Unit 
• Container , etc

The Coffee Vending Machine controller is a Finite State Machine(FSM). Let’s assume the machine is capable of making two coffee recipes by default:

• Cappuccino( Strong /Regular)
• Espresso (Strong /Regular)

However, the machine operator can add new coffee recipes to the machine. A coffee recipe consists of recipe name, coffee powder units in table spoons, milk in ml, super in table spoons, and recipe price in dollars.

Use cases

The main actors of the system:

• Customer
• Machine operator

 

 

Test cases

The main intended purpose of the coffee machine for the customer is to make coffee.

Functional Test Cases

Verify that when user deposits money and select the coffee recipe in the menu, the machine should dispense the selected coffee drink to the customer.

Verify that coffee is not dispensed, when the customer does not enter enough money. The money should be returned to the customer.

Verify that upon insufficient inventory, the machine should display an error message to the customer.

Verify that invalid coins are ejected out to the customer.

Functional testcases in table format:

Test Case ID	Test Scenario	Test Steps	Expected Result
TC01	Power ON Machine	Switch on the vending machine	Machine should power on and display welcome message
TC02	Select Coffee Option	Choose “Coffee” from menu options	Machine should display selected coffee option
TC03	Insert Sufficient Coins	Insert valid coins as per coffee price	Machine should accept coins and update balance
TC04	Insert Insufficient Coins	Insert fewer coins than required	Machine should show “Insufficient Balance” message
TC05	Dispense Coffee	After inserting sufficient coins, press “Start”	Machine should dispense hot coffee into cup
TC06	Check Sugar Level Option	Select sugar level before making coffee	Coffee should be dispensed with chosen sugar level
TC07	Check Milk Option	Select milk preference (with/without milk)	Coffee should be prepared as per selected option
TC08	Cancel Transaction	Insert coins → Press “Cancel”	Machine should return inserted coins
TC09	Out of Coffee Powder	Try ordering when coffee powder is empty	Machine should display “Out of Service” or “Refill Required”
TC10	Check Cup Availability	Try ordering when cups are empty	Machine should display “No Cups Available” message
TC11	Refund Extra Balance	Insert more coins than required	Machine should return balance after dispensing coffee
TC12	Machine Timeout	Leave machine idle after inserting coins	Machine should cancel transaction and return coins after timeout
TC13	Invalid Coin Detection	Insert invalid coin	Machine should reject coin and return it
TC14	Power OFF Machine	Switch off the vending machine	Machine should shut down safely

 

GUI Test Cases

Verify the Display Menu options for Cappuccino and Espresso.

Verify that the buttons are working properly.