ChatDiagram
Use Case Diagrams · E-commerce · System Design

Online Auction System Use Case Diagram

Type UML use case diagramStandard OMG UML 2.5.1 §18Engine schematex-usecaseUpdated 6/26/2026
Online Auction System Use Case Diagram
Drawing preview
The scenario

An online auction platform where bidders place manual or automatic bids, sellers list items, and a payment gateway processes winning bids. The diagram shows key use cases and their relationships.

What is in this drawing

Read the decisions behind it.

01

Modeled automatic bid as an include of Place Bid

02

Outbid notification extends Place Bid via extension point

03

Payment Gateway as external actor

Reusable for any auction or marketplace system with proxy bidding and payment integration.

More like this

Other examples in this family.

Browse all use case diagram templates →