Summary: Designing an Online Stock Brokerage System

Now that you’ve completed the online stock brokerage system case study, let’s take a moment to reflect on and consolidate what we’ve learned. We’ll revisit the key system requirements, identify the core classes along with their responsibilities and relationships, and highlight the major design principles applied. We’ll also examine how objects interact within the system and walk through the overall workflow to understand how the components come together to achieve the desired functionality.

Key requirements

Below are the primary functional and non-functional requirements that define the scope of the Online Stock Brokerage System:

1. The system must allow users to easily trade in stocks (buy or sell stocks).

2. Users can maintain multiple watchlists, each with different stock quotes.

3. The system should track different lots of the same stock for each user, distinguishing between several purchases of the same stock.

4. Users must receive notifications whenever trade orders are executed.

5. The system must support various order types: market order, limit order, stop-loss order, and stop-limit order.

6. Deposits and withdrawals should be supported via check, wire, and electronic bank transfers.

System actors

The following primary actor interacts with the system: ...