Software Design

Modeling E-Commerce Cart to Order Checkout

UML Class Diagrams · made in Skemio

UML class diagram showing Cart containing CartItems, checking out into an Order containing OrderLines, with DiscountPolicy applied to the Order.
UML class diagram showing Cart containing CartItems, checking out into an Order containing OrderLines, with DiscountPolicy applied to the Order.
Open it in SkemioMake your own

What it shows

  • Carts calculate live estimates; orders freeze prices as immutable snapshots.
  • Line items capture item price at time of purchase, isolating catalog edits.
  • Discounts and taxes attach as line adjustments to maintain clean ledger math.

The takeaway

Never convert a cart to an order by updating a status flag; snapshot the lines immutably.

More uml class diagrams