The provided document presents a design class diagram for SIT773, focusing on the Leckie's Choice (LC) case study. The diagram illustrates the relationships between different classes such as user, account, customer, shopping cart, payment, order, and line item. It specifies data types, methods, and class interactions, including the management of customer accounts, shopping carts, and order processing. The document also references relevant academic articles and provides a visual representation of the class diagram, showing the structure of the LC system. The diagram shows the connections between users, customers, and their interactions with the system's core components. The class diagram also includes payment processing and order management functionalities. The document includes a bibliography of the sources used. This assignment is a solution to the SIT773 software requirements and analysis task, demonstrating an understanding of software design principles.