Design an OOD restaurant management system

Object-oriented design: Restaurant management system

Design an object-oriented system for a dine-in restaurant that supports the following:

Functional requirements

• The restaurant has tables with capacity; parties can be seated at a table.
• A party can create one or more orders ; an order contains multiple order items (menu item + quantity + special instructions).
• The kitchen tracks order item states (e.g., PLACED , IN_PREP , READY , SERVED , CANCELLED ).
• The restaurant generates a bill for a table/party and supports splitting the bill (by item or by amount).
• Payment can be made via multiple methods (cash/card); a bill can have multiple payments.

Non-functional / design goals

• Clean separation of concerns (table management, ordering, kitchen workflow, billing/payments).
• Extensible to add features later (takeout/delivery, discounts, loyalty).

What to provide

• Key classes, fields, and methods (UML-style text is fine).
• Important relationships (composition/aggregation) and patterns if appropriate.
• Brief explanation of how typical flows work (seat → order → prepare → serve → bill → pay).