Question

Use case diagram Vending Machine: After client interview the following system scenarios were identified:

• A customer buys a product

• The supplier restocks the machine

• The supplier collects money from the machine

A use case diagram provides a high level visual representation of user requirements. Design a high level use case diagram that represents the above system, identify all actors. At the very least your use case diagram should clearly show all actors (stick figures), the system, use Page 2 of 2 cases or services that the system knows how to perform, and interaction/relationship between the elements of the system. Optionally you may add sub-diagrams to show more details.

Answer 1

Based on the given scenario , UML Use Case diagram developed using and online free tool

• The actors are customer, machine and supplier
• Customer buys product which includes choosing the product , entering the needed quantity and inserting the price money into the machine
• The machine show products which includes listing the products
• Listing products extends showing the price of each product
• The machine dispense the product which extends checking the paid amount by the customer for specified quantity
• When the products stocks reaches to a re-order level the supplier restock the product into the machine
• The customer collects the money paid by customers from the machine

Note : Since the diagram didn't fit the page of the online tool , it is not clear while the picture size was reduced to 60 % to fit the display window as below. So I cut the diagram into 3 images for more clarity to view ,below this full diagram

The above diagram into 3 images for more clarity to view as below

Customer interacting with the vending machine system

Machine's automated interaction as a vending machine system

Supplier interacting with the vending machine system